FPDoc :
Free Pascal code documenter: Reference manual

Michaël Van Canneyt

Contents

Chapter 1  Introduction

1.1  About this document

This is the reference manual for FPDoc , a free documentation tool for Pascal units. It describes the usage of FPDoc and how to write documentation with it.

It attempts to be complete, but the tool is under continuous development, and so there may be some slight differences between the documentation and the actual program. In case of discrepancy, the sources of the tool are the final reference. A README or CHANGES file may be provided, and can also give some hints as to things which have changed. In case of doubt, these files or the sources are authoritative.

1.2  About FPDoc

FPDoc is a tool that combines a Pascal unit file and a description file in XML format and produces reference documentation for the unit. The reference documentation contains documentation for all of the identifiers found in the unit’s interface section. The documentation is fully cross-referenced, making it easy to navigate. It is also possible to refer to other documentation sets written with FPDoc , making it possible to maintain larger documentation sets for large projects.

Contrary to some other documentation techniques, FPDoc does not require the presence of formatted comments in the source code. It takes a source file and a documentation file (in XML format) and merges these two together to a full documentation of the source. This means that the code doesn’t get obfuscated with large pieces of comment, making it hard to read and understand.

FPDoc is package-oriented, which means that it considers units as part of a package. Documentation for all units in a package can be generated in one run.

At the moment of writing, the documentation can be generated in the following formats:

HTML
Plain HTML. Javascript is used to be able to show a small window with class properties or class methods, but the generated HTML will work without JavaScript as well. Style sheets are used to do the markup, so the output can be customised.
XHTML
As HTML, but using a more strict syntax.
LaTeX
LaTeX files, which can be used with the fpc.sty file which comes with the Free Pascal documentation. From this output, PDF documents can be generated, and with the use of latex2rtf, RTF or Winhelp files. Text files can also be generated.
Text
plain ascii text files. No cross-referencing exists. Other than that it resembles the LaTeX output in it’s structure.
Man
Unix man pages. Each function/procedure/method identifier is a man page. Constants are on a separate page, as are types, variables and resourcestrings.
CHM
HTML files compressed into a .chm file using lzx compression.
RTF
Linear RTF files.

Note that pascal program files cannot be parsed by fpdoc, it is therefor impossible to create documentation for a program. Only units are supported.

1.3  Getting more information.

If the documentation doesn’t give an answer to your questions, you can obtain more information on the Internet, on the Free Pascal Website:

http://www.freepascal.org/ http://www.freepascal.org

It contains links to download all FPDoc related material.

Finally, if you think something should be added to this manual (entirely possible), please do not hesitate and contact me at michael@freepascal.orgmailto:michael@freepascal.org.

Chapter 2  Compiling and Installing FPDoc

2.1  Compiling

In order to compile FPDoc , the following things are needed:

  1. The fpdoc sources. These can be downloaded from the FPDoc website.
  2. The Free Pascal compiler sources. FPDoc uses the scanner from the Free Pascal comiler to scan the source file.
  3. The FCL units (or their sources) should be installed.
  4. fpcmake is needed to create the makefile for fpdoc. It comes with Free Pascal , so if Free Pascal is installed, there should be no problem.
  5. To make new internationalisation support files, rstconv must be installed, and the GNU gettext package.

Links to download all these programs can be found on the FPDoc website.

When the fpdoc sources have been unzipped, the Makefile must be generated. Before generating the makefile, the location of the compiler source directory should be indicated. In the Makefile.fpc file, which has a windows ini file format, locate the fpcdir entry in the defaults section:

fpcdir=../..

and change it so it points to the top-level Free Pascal source directory.

After that, running fpcmake will produce the Makefile, and running make should produce 2 executables: fpdoc and makeskel.

2.2  Installation

When installing from sources, a simple

make install
cd intl
make install

should completely install the documentation tool.

When installing from a archive with the binaries, it should be sufficient to copy the binaries to a directory in the PATH.

To have fpdoc available in several languages, the language files should be installed in the following directory on Unix systems:

/usr/local/share/locale/XX/LC_MESSAGES/

or

/usr/share/locale/XX/LC_MESSAGES/

Depending on the setup. Here XX should be replaced by the locale identifier.

Chapter 3  FPDoc usage

3.1  fpdoc

Using FPDoc is quite simple. It takes some command-line options, and based on these options, creates documentation. The command-line options can be given as long or short options, as is common for most GNU programs.

In principle, only 2 command-line options are needed:

package
This specifies the name of the package for which documentation must be created. Exactly one package option can be specified.
input
The name of a unit file for which documentation should be generated. This can be a simple filename, but can also contain some syntax options as they could be given to the Free Pascal scanner. More than one input option can be given, and documentation will be generated for all specified input files.

Some examples:

fpdoc --package=fcl --input=crt.pp

This will scan the crt.pp file and generate documentation for it in a directory called fcl.

fpdoc --package=fcl --input='-I../inc -S2 -DDebug classes.pp'

This will scan the file classes.pp, with the DEBUG symbol defined, the scanner will look for include files in the ../inc directory, and OBJFPC-mode syntax will be accepted.

(for more information about these options, see the Free Pascal compiler user’s guide)

With the above commands, a set of documentation files will be generated in HTML format (this is the standard). There will be no description of any of the identifiers found in the unit’s interface section, but all identifiers declarations will be present in the documentation.

The actual documentation (i.e. the description of each of the identifiers) resides in a description file, which can be specified with the descr option:

fpdoc --package=fcl --descr=crt.xml --input=crt.pp

This will scan the crt.pp file and generate documentation for it, using the descriptions found in the filecrt.xml file. The documentation will be written in a directory called fcl.

fpdoc --package=fcl --descr=classes.xml \
      --input='-I../inc -S2 -DDebug classes.pp'

All options should be given on one line. This will scan the file classes.pp, with the DEBUG symbol defined, the scanner will look for include files in the ../inc directory, and OBJFPC-mode syntax will be accepted.

More than one input file or description file can be given:

fpdoc --package=fcl --descr=classes.xml --descr=process.xml \
      --input='-I../inc -S2 -DDebug classes.pp' \
      --input='-I../inc -S2 -DDebug process.pp'

Here, documentation will be generated for 2 units: classes and process

The format of the description file is discussed in the next chapter.

Other formats can be generated, such as latex:

fpdoc --format=latex --package=fcl \
      --descr=classes.xml --descr=process.xml\
      --input='-I../inc -S2 -DDebug classes.pp' \
      --input='-I../inc -S2 -DDebug process.pp'

This will generate a LaTeX file called fcl.tex, which contains the documentation of the units classes and process. The latex file contains no document preamble, it starts with a chapter command. It is meant to be included (using the LaTeX include command) in a latex document with a preamble.

The output of FPDoc can be further customised by several command-line options, which will be explained in the next section.

3.2  FPDoc command-line options reference

In this section all FPDoc command-line options are explained.

3.2.1  auto-index

This option generates an index of all the types including objects, classes, their methods and enums, sorted alphabhetically. Methods of classes and objects will appear as subitems of their class. If used in combination with –index-file this option will be used instead. This option only applies to the chm backend.

3.2.2  auto-toc

This option generates a Table of Contents that displays all classes, objects and routines in several ways. If used in combination with –toc-file this option will be used instead. This option only applies to the chm backend.

3.2.3  charset

This option can be used to specify the character set to be used for the HTML backend. It is simply inserted in the HTML tree. The default character set is iso-8859-1

For example

--charset=UTF8

will result in an UTF8 specification of the content attribute of the meta tag in the generated HTML file:

<meta content="text/html; charset=UTF8" http-equiv="Content-Type">

3.2.4  content

This option tells FPDoc to generate a content file. A content file contains a list of all the possible anchors (labels) in the generated documentation file, and can be used to create cross-links in documentation for units in other packages, using the counterpart of the content option, the import option (section ??, page ?? ).

3.2.5  css-file

This option only applies to the chm backend. Use this option to set the css file used to style the html when the html is rendered by a viewer.

3.2.6  default-page

This option only applies to the chm backend. The default page to load when the chm is opened by a viewer. Using this option does not include a file but instead specifies a file you have included using –other-files. You only need to use this option if you have used the –other-files option and included a page you wish to use instead of the default page.

3.2.7  descr

This option specifies the name of a description file that contains the actual documentation for the unit. This option can be given several times, for several description files. The file will be searched relative to the current directory. No extension is added to the file, it should be a complete filename.

If the filename starts with an ’at’ sign @, then it is interpreted as a text file which contains a list of filenames, one per line. Each of these files will be added to the list of description files.

The nodes in the description files will be merged into one big tree. This means that the documentation can be divided over multiple files. When merging the description files, nodes that occur twice will end up only once in the big node tree: the last node will always be the node that ends up in the parse tree. This means that the order of the various input commands or the ordering of the files in the file list is important.

Examples:

--descr=crt.xml 

will tell FPDoc to read documentation from crt.xml, while

--descr=@fcl.lst 

will tell FPDoc to read filenames from fcl.lst; each of the filenames found in it will be added to the list of files to be scanned for descriptions.

3.2.8  footer

This option tells the HTML engine to include the file indicated by this option as the footer of each generated HTML page. The file is assumed to contain a valid XHTML fragment. The contents of the file will be inserted in the HTML tree.

Example:

--footer=footer.xml

Where footer.xml contains for example:

<hr/>
<i>Date generated : June 1, 2008</i>

This option is mutually exclusive with the footer-date option.

3.2.9  footer-date

This option tells the HTML engine to generate a footer for each page containing the current date. The optional format argument can be used to specify the format of the date. The format must be a formatting string as understoof by the FormatDateTime function in the sysutils unit.

For example

--footer-date='mmm dd yyyy'

This option is mutually exclusive with the footer option.

3.2.10  format

Specifies the output format in which the documentation will be generated. Currently, the following formats are known:

htm
Plain HTML with 8.3 conforming filenames.
html
HTML with long filenames.
xhtml
XHTML with long filenames.
latex
LaTex, which uses the fpc.sty style used by the Free Pascal documentation.
xml-struct
Structured XML.
chm
Compressed HTML.

3.2.11  help

Gives a short copyright notice.

3.2.12  hide-protected

By default, the documentation will include descriptions and listings of protected fields and methods in classes or objects. This option changes this behaviour; if it is specified, no documentation will be generated for these methods. Note that public methods or properties that refer to these protected methods will then have a dangling (i.e. unavailable) link.

3.2.13  html-search

This option can be used when generating HTML documentation, to specify an url that can be used to search in the generated documentation. The URL will be included in the header of each generated page with a Search caption. The option is ignored for non-html output formats.

FPDoc does not generate a search page, this should be made by some external tool. Only the url to such a page can be specified.

Example:

--html-search=../search.html

3.2.14  image-dir

This option tells the backend where the images are located. By default, a directory images is assumed. A path using forward slashes must be provided.

Example:

--image-dir=pictures/

3.2.15  image-url

This option tells the HTML backend where the images are located: the argument must be an absolute URL. By default, the images are assumed to be in a images directory below the package directory. Note that the URL must be absolute, i.e. if it is provided, the link to the image will be composed from the argument of this option with the filename.

Example:

--image-url=http://www.mysite.org/docs/pictures/

3.2.16  import

Import a table of contents file, generated by FPDoc for another package with the content option (section ??, page ?? ). This option can be used to refer to documentation nodes in documentation sets for other packages. The argument consists of two parts: a filename, and a link prefix.

The filename is the name of the file that will be imported. The link prefix is a prefix that will be made to each HTML link; this needs to be done to be able to place the files in different directories.

Example:

--import=../fcl.cnt,../fcl

This will read the file fcl.cnt in the parent directory. For HTML documentation, all links to items in the fcl.cnt file, the link will be prepended with ../fcl.

This allows a setup where all packages have their own subdirectory of a common documentation directory, and all content files reside in the main documentation directory, as e.g. in the following directory tree:

/docs/fcl
     /fpdoc
     /fpgui
     /fpgfx
     /fpimg

The file fcl.cnt would reside in the docs directory. Similarly, for each package a contents file xxx.cnt could be places in that directory. Inside the subdirectory, commands as the above could be used to provide links to other documentation packages.

Example:

--import=../fcl.cnt,ms-its:fcl.chm::/

As in the previous example this will read the file fcl.cnt in the parent directory. But all links to items in the fcl.cnt file, will be prepended with ms-its:fcl.chm::/. This is how chm’s are crosslinked.

Note that for Latex documentation, this option is ignored.

3.2.17  index-colcount

For the HTML backend, this option can be used to specify the number of columns that should be used when generating an identifier index page. By default, 3 columns are used.

Example:

--index-colcount=4

Will use 4 columns instead.

3.2.18  index-file

Use this option to specify a local file to include and use as the index. This file is in the sitemap format. You can use the unit chmsitemap in your programs to read and write this type of file. Usually this file ends with .hhk. This option only applies to the chm backend.

3.2.19  input

This option tells FPDoc what input file should be used. The argument can be just a filename, but can also be a complete compiler command-line with options that concern the scanning of the Pascal source: defines, include files, syntax options, as they would be specified to the Free Pascal compiler when compiling the file. If a complete command is used, then it should be enclosed in single or double quotes, so the shell will not break them in parts.

It is possible to specify multiple input commands; they will be treated one by one, and documentation will be generated for each of the processed files.

3.2.20  lang

Select the language for the generated documentation. This will change all header names to the equivalent in the specified language. The documentation itself will not be translated, only the captions and headers used in the text.

Currently, valid choices are

de
German.
fr
French.
nl
Dutch.

Example:

--lang=de

Will select German language for headers.

The language files should be installed correctly for this option to work. See the section on installing to check whether the languages are installed correctly.

3.2.21  latex-highlight

Switches on an internal latex syntax highlighter. This is not yet implemented. By default, syntax highlighting is provided by the syntax package that comes with Free Pascal .

3.2.22  make-searchable

This option generates an index of all the *.htm* files added in the chm, including files added with the –other-files option so that a full text search is possible. This option only applies to the chm backend.

3.2.23  other-files

This option specifies a text file with one filename per line to be included in the chm. You can include any type of file you want; it does not have to be a html file. For instance you can include images that you have linked to in the xml descr files. The files should be in a subfolder of the working directory and within their own folder to avoid naming conflicts with the auto generated files. This option only applies to the chm backend.

3.2.24  output

This option tells FPDoc where the output file should be generated. How this option is interpreted depends on the format that is used. For latex, this is interpreted as the filename for the tex file. For chm, this is interpreted as the output filename. For all other formats, this is interpreted as the directory where all documentation files will be written. The directory will be created if it does not yet exist.

The filename or directory name is interpreted as relative to the current directory.

Example:

--format=html --output=docs/classes

will generate HTML documentation in the directory docs/classes.

--format=latex --output=docs/classes.tex

will generate latex documentation in the file docs/classes.

--format=chm --output=docs.chm

will generate chm documentation in the file docs.chm.

3.2.25  package

This option specifies the name of the package to be used. The package name will also be used as a default for the output option (section ??, page ?? ).

3.2.26  show-private

By default, no documentation is generated for private methods or fields of classes or objects. This option causes FPDoc to generate documentation for these methods and fields as well.

3.2.27  toc-file

Use this option to specify a local file to include as a the Table of Contents. The table of contents is in the sitemap format and usually ends in .hhc. You can use the unit chmsitemap in your programs to read and write files of this type. This option only applies to the chm backend of FPDoc .

3.2.28  warn-no-node

If this option is given, then fpdoc will emit a warning if it cannot find a documentation node for some identifier. This can be used to see whether the description files are up-to-date, or whether they must be updated.

3.3  makeskel

3.3.1  introduction

The makeskel tool can be used to generate an empty description file for a unit. The description file will contain an element node for each identifier in the interface section of the Pascal unit.

It’s usage is quite straightforward: the name of an input file (one or more) must be specified (as for FPDoc ), an output file, and the name of a package:

makeskel --package=rtl --input=crt.pp --output=crt.xml

This will read the file crt.pp and will create a file crt.xml which contains empty nodes for all identifiers found in crt.pp, all in a package named rtl.

The input option can be given more than once, as for the fpdoc command:

makeskel --input='-Sn system.pp' --input=crt.pp --output=rtl.xml

As can be seen, the input option can contain some compiler options, as is the case for FPDoc . The above command will process the files system.pp and crt.pp, and will create element tags for the identifiers in both units in the file rtl.xml.

The output of makeskel is a valid, empty description file. It will contain a module tag for each unit specified, and each module will have element tags for each identifier in the unit.

Each element tag will by default contain short, descr, errors and seealso tags, but this can be customised.

3.4  Makeskel option reference

The output of makeskel can be customised using several options, which are discussed below.

3.4.1  descr

When in update mode (section ??, page ?? ), this opion can be used to add an existing documentation file, as for fpdoc. Nodes that are already in one of the existing documentation files will not be written to the output file.

3.4.2  disable-arguments

By default, for each function or procedure argument, a element tag will be generated. This option disables this behaviour: no element tags will be generated for procedure and function arguments.

3.4.3  disable-errors

If this option is specified, no errors tag will be generated in the element nodes. By default all element tags contain a errors node.

The errors tag is ignored when it is not needed; Normally, an errors tag is only needed for procedure and function elements.

3.4.4  disable-function-results

If this option is specified, then no element tag will be generated for function results. By default, makeskel will generate a result node for each function in the interface section. The result node is used in the documentation to document the return value of the function under a separate heading in the documentation page. Specifying this option suppresses the generation of the element tag for the function result.

3.4.5  disable-override

If this option is specified, then no element tags will be generated for methods that override a method in a parent class. This means that the fpdoc engine will refer to the parent implementation for the documentation of the inherited method (provided it can find a parent implementation).

3.4.6  disable-private

If this option is specified, then no element tags will be generated for private methods or fields of classes or objects. The default behaviour is to generate nodes for private methods or fields. It can be used to generate a skeleton for end-user and developer documentation.

3.4.7  disable-protected

If this option is specified, then no element tags will be generated for protected and private methods or fields of classes or objects. The default is to generate nodes for protected methods or fields. If this option is given, the option --disable-private is implied. It can be used to generate end-user-only documentation for classes.

3.4.8  disable-seealso

If this option is specified, no seealso tag will be generated in the element nodes. By default all element tags contain a seealso tag.

3.4.9  emitclassseparator

When this option is specified, at the beginning of the elements for the documentation of a class, a comment tag is emitted which contains a separator text. This can be useful to separate documentation of different classes and make the description file more understandable.

3.4.10  help

Makeskel emits a short copyright notice and exits when this option is specified.

3.4.11  input

This option is identical in meaning and functionality as the input option for FPDoc . (section ??, page ?? ) It specifies the Pascal unit source file that will be scanned and for which a skeleton description file will be generated. Multiple input options can be given, and element tags will be written for all the files, in one big output file.

3.4.12  lang

This option is used to specify the language for messages emitted by makeskel. The supported languages are identical to the ones for FPDoc :

de
German.
fr
French.
nl
Dutch.

3.4.13  output

This option specifies the name of the output file. A full filename must be given, no extension will be added. If this option is omitted, the output will be sent to standard output.

When using update mode, the output file name should not appear in the list of existing documentation files. The makeskel program will do some elementary checks on this.

3.4.14  package

This option specifies the package name that will be used when generating the skeleton. It is a mandatory option.

3.4.15  update

This option tells makeskel to create an update file: it will read description files (section ??, page ?? ) and will only create documentation nodes for identifiers which do not yet have a documentation node in the read documentation files. The output file in this case can be merged with one (or more) of the documentation files: it’s name should not appear in the list of existing documentation files. The makeskel program will do some elementary checks on this.

Chapter 4  The description file

4.1  Introduction

The description file is a XML document, which means that it is a kind of HTML or SGML like format, however it is more structured than HTML, making it easier to parse - and makes it easier to connect or merge it with a Pascal source file. Since the allowed syntax uses a lot of HTML tags, this makes it easy to write code for those that are familiar with writing HTML.

More information about the XML format, SGML and HTML can be found on the website of the W3 (World Wide Web) consortium: http://www.w3.org/http://www.w3.org

The remaining of this chapter assumes a basic knowledge of tags, their attributes and markup language, so these terms will not be explained here.

The minimal documentation file would look something like this:

<?xml version="1.0" encoding="ISO-8859-1"?>
<fpdoc-description>
<package name="fpc">
<module name="Classes">
</module>
</package>
</fpdoc-description>

The header xml tag is mandatory, and indicates that the file contains a documentation XML document.

Inside the document, one or more top-level fpdoc-descriptions tags may appear. Each of these tags can contain one or more package tags, which must have a name attribute. The name attribute will be used by fpdoc to select the documentation nodes.

Inside a package tag, one or more module tags may appear. there should be one module tag per unit that should be documented. The value of the name attribute of the module should be the name of the unit for which the module tag contains the documentation. The value of the name attribute is case insensitive, i.e.

<module name="CRT">

can be used for the documentation of the crt unit.

As it is above, the documentation description does not do much. To write real documentation, the module tag must be filled with the documentation for each identifier that appears in the unit interface header.

For each identifier in the unit interface header, the module should contain a tag that documents the identifier: this is the element tag. The name attribute of the element tag links the documentation to the identifier: the name attribute should have as value the fully qualified name of the identifier in the unit.

For example, to document the type

Type
  MyEnum = (meOne,meTwo,meThree);

an element tag called myenum should exist:

<element name="myenum">
</element>

But also for each of the three enumerated values an element tag should exist:

<element name="myenum.meOne">
</element>
<element name="myenum.meTwo">
</element>
<element name="myenum.meThree">
</element>

As it can be seen, the names of the identifiers follow a hierarchical structure. More about this in the next section.

Now the tags for the types are present, all that should be done is to fill it with the actual description. For this, several tags can be placed inside a element tag. The most important tag is the descr tag. The contents of the descr tag will be used to describe a type, function, constant or variable:

<element name="myenum">
<descr>
The MyEnum type is a simple enumeration type which is not
really useful, except for demonstration purposes.
</descr>
</element>

A second important tag is the short tag. It should contain a short description of the identifier, preferably a description that fits on one line. The short tag will be used in various overviews, at the top of a page in the HTML documentation (a synopsis) or will be used instead of the descr tag if that one is not available. It can also be used in different other cases: For instance the different values of an enumeration type will be laid out in a table, using the short description:

<element name="myenum.meOne">
<short>The first enumeration value</short>
</element>
<element name="myenum.meTwo">
<short>The second enumeration value</short>
</element>
<element name="myenum.meThree">
<short>The third enumeration value</short>
</element>

This will be converted to a table looking more or less like this:

meOneThe first enumeration value
meTwoThe second enumeration value
meThreeThe third enumeration value

For functions and procedures, a list of possible error conditions can be documented inside a errors tag. This tag is equivalent to the descr tag, but is placed under a different heading in the generated documentation.

Finally, to cross-reference between related functions, types or classes, a seealso tag is also introduced. This will be used to lay out a series of links to related information. This tag can only have sub-tags which are link tags. For more about the link tag, see link (??) .

If a certain identifier has appeared only in a certain version of a library, then this information can be specified in a version tag, see version (??) for more information.

The following example illustrates the use:

<element name="myenum">
<descr>
The MyEnum type is a simple enumeration type which is not
really useful, except for demonstration purposes.
</descr>
<version>The myenum type appeared in version 2.1</version>
</element>

When documenting methods or properties, it is possible to let the fpdoc engine refer to the parent method when it generates an overview of methods or properties. There are 2 ways of achieving this:

  1. Do not include an element tag
  2. Specify the link attribute, with the name of the parent method which contains the documentation, as in the following example:
    <element name="TParent.SomeMethod">
    </element
    
    <element name="TChild.SomeMethod" link="TParent.SomeMethod"/>
    
    this can be used to speed up the search for the parent implementation, or to skip several parent classes.

To add a section or page of documentation that is not directly related to a single identifier in a unit, a topic tag can be used. This tag can appear inside a package or module tag, and can contain a short or descr tag. The contents of the short tag will be used for the title of the section or page. In on-line formats, a short list of related topics will appear in the package or module page, with links to the pages that contain the text of the topics. In a linear format, the topic sections will be inserted before the description of all identifiers.

If the topic appears in a package tag, then it can be nested: 2 levels of topics may be used. This is not so for topics inside a module: they can not be nested (the level of nesting in a linear documentation format is limited).

The following is an example of a valid topic tag:

<module name="CRT">
<topic name="UsingKeyboard">
<short>Using the keyboard functions</short>
<descr>
To use the keyboard functions of the CRT unit, one...
</descr>
</topic>

Topic nodes can be useful to add ’how to’ sections to a unit, or to provide general IDE help.

4.2  Element names and cross-referencing

4.2.1  Element name conventions

As mentioned in the previous section, the element tag’s name attribute is hierarchical. All levels in the hierarchy are denoted by a dot (.) in the name attribute.

As shown in the previous example, for an enumerated type, the various enumeration constants can be documented by specifying their name as enumname.constname. For example, given the type

Type
  MyEnum = (meOne,meTwo,meThree);

The various enumeration values can be documented using the element names MyEnum.meOne, MyEnum.meTwo and MyEnum.meThree:

<element name="myenum.meOne">
</element>
<element name="myenum.meTwo">
</element>
<element name="myenum.meThree">
</element>

Note that the casing of the name attribute need not be the same as the casing of the declaration.

This hierarchical structure can be used for all non-simple types:

4.2.2  Cross referencing: the link tag

To refer to another point in the documentation (a related function, class or whatever), a link tag exists. The link tag takes as a sole attribute a target id attribute. The link tag usually encloses a piece of text. In the HTML version of the documentation, this piece of text will function as a hyperlink. In the latex version, a page number reference will be printed.

The id attribute contains the name of an element to which the link refers. The name is not case sensitive, but it must be a fully qualified name.

An example of the link type would be:

The <link id="MyEnum">MyEnum</link> type is a simple type.

The link attribute also has a short form:

The <link id="MyEnum"/> type is a simple type.

In the short form, the value of the id attribute will be used as the text which will be hyperlinked. This is especially useful in the seealso tag.

To refer to a type in another unit, the unit name must be prepended to the id attribute:

<link id="myunit.myenum"/>

will link to the myenum type in a unit named myunit.

To refer to a node in the documentation of another package, the package name should be prepended to the id attribute, and it should be prepended with the hash symbol (#):

<link id="#fcl.classes.sofrombeginning"/>

will link to the constant sofrombeginning in the classes unit of the FCL reference documentation. Note that for this to work correctly, the contents file which was created when generating the documentation of the type must be imported correctly (see the import option).

4.3  Tag reference

4.3.1  Overview

The tags can roughly be divided in 2 groups:

  1. Documentation structure tags. These are needed for fpdoc to do it’s work. They determine what elements are documented. See table (??)
  2. Text structure and formartting tags. These tags indicate blocks of text, such as paragraphs, tables, lists and remarks, but also specify formatting: apply formatting (make-up) to the text, or to provide links to other parts of the text. These mostly occur in text structure tags. See table (??)

Table 4.1: Documentation structure tags
TagDescriptionPage
descrElement description??
elementIdentifier documentation??
errorsError section??
fpdoc-descriptionGlobal tag??
moduleUnit tag??
packagePackage global tab??
seealsoCross-reference section??
shortShort description??
topicTopic page??


Table 4.2: Text formatting tags
TagDescriptionPage
bFormat bold??
captionSpecify table caption??
codeSyntax highlight code??
dddefinition data??
dldefinition list??
dtDefinition term??
iformat italics??
imginclude image??
lilist element??
linkCross-reference??
olnumbered list??
pparagraph??
prePreformatted text??
remarkremark paragraph??
tableTable??
tdTable cell??
thTable header??
trTable row??
uformat underlined??
ulbulleted list??
varformat as variable??

The nodes for formatting a text resemble closely the basic HTML formatting tags with the following exceptions:

Also, if special formatting tags such as a table or lists are inserted, then the remaining text must be inside a paragraph tag. This means that the following is wrong:

<descr>
Some beginning text
<ol>
<li>A list item</li>
</ol>
some ending text
</descr>

Instead, the correct XML should be

<descr>
<p>Some beginning text</p>
<ol>
<li>A list item</li>
</ol>
<p>some ending text</p>
</descr>

4.3.2  b : format bold

This tag will cause the text inside it to be formatted using a bold font.

Example:

Normal text <b>Bold text</b> normal text.

will be formatted as:
Normal text Bold text normal text.

See also: i (??) , u (??) .

4.3.3  caption : Specify table caption

This tag can occur inside a table tag and serves to set the table caption.

Example

<table>
<caption>This caption will end up above the table</caption>
<th><td>Column 1</td><td>Column 2</td></th>
</table>

See also: table (??)

4.3.4  code : format as pascal code

The code tag serves to insert Pascal code into the text. When possible this code will be highlighted in the output. It can be used to put highlighted Pascal code in the documentation of some identifier. It can occur inside descr or errors tags.

Note that any text surrounding the code tag should be placed in paragraph tags p.

Example:

<code>
With Strings do
  For i:=Count-1 downto 0 do
    Delete(i);
</code>

Seealso: pre (??) , p (??)

4.3.5  descr : Descriptions

This is the actual documentation tag. The contents of this tag will be written as the documentation of the element. It can contain any mixture of text and markup tags. The descr tag can only occur inside a element or module.

Example:

<element name="MyEnym">
<descr>Myenum is a simple enumeration type</descr>
</element>

See also: element (??) , short (??) , errors (??) , seealso (??)

4.3.6  dd : definition data.

The dd tag is used to denote the definition of a term in a definition list. It can occur only inside a definition list tag (dl), after a definition term (dt) tag. It’s usage is identical to the one in HTML.

Example:

<dl>
<dt>FPC</dt><dd>stands for Free Pascal Compiler.</dd>
</dl>

Will be typeset as

FPC
stands for Free Pascal Compiler.

See also: dl (??) , dt (??) , ol (??) , ul (??)

4.3.7  dl : definition list.

Definition lists are meant to type a set of terms together with their explanation. It’s usage is identical to the one in HTML, with the exception that it cannot occur inside ordinary text: surrounding text should always be enclosed in paragraph tags.

Example:

<dl>
<dt>meOne</dt><dd>First element of the enumeration type.</dd>
<dt>meTwo</dt><dd>Second element of the enumeration type.</dd>
<dt>meThree</dt><dd>Thir element of the enumeration type.</dd>
</dl>

Will be typeset as

meOne
First element of the enumeration type.
meTwo
Second element of the enumeration type.
meThree
Third element of the enumeration type.

See also: dt (??) , dd (??) , ol (??) , ul (??)

4.3.8  dt : definition term.

The dt tag is used in definition lists to enclose the term for which a definition is presented. It’s usage is identical to the usage in HTML.

Example:

<dl>
<dt>FPC</dt><dd>stands for Free Pascal Compiler.</dd>
</dl>

Will be typeset as

FPC
stands for Free Pascal Compiler.

See also: dl (??) , dd (??) , ol (??) , ul (??)

4.3.9  element : Identifier documentation

The element contains the documentation for an identifier in a unit. It should occur inside a module tag. It can contain 4 tags:

short
For a one-line description of the identifier. Is used as a header or is used in overviews of constants, types, variables or classes.
descr
Contains the actual description of the identifier.
errors
For functions an procedures this can be used to describe error conditions. It will be put in a separate section below the description section.
seealso
Used to refer to other nodes. will be typeset in a separate section.

The element tag should have at least the name attribute, it is used to link the element node to the actual identifier in the Pascal unit. Other attributes may be added in future.

Example:

<element name="MyEnym">
<descr>Myenum is a simple enumeration type</descr>
</element>

See also: descr (??) , short (??) , errors (??) , seealso (??)

4.3.10  errors : Error section.

The errors tag is used to document any errors that can occur when calling a function or procedure. it is placed in a different section in the generated documentation. It occurs inside a element tag, at the same level as a descr or short tag. It’s contents can be any text or formatting tag.

Example:

<element name="MyDangerousFunction">
<descr>MyDangerousFunction is a dangerous function</descr>
<errors>When MyDangerousFunction fails, all is lost</errors>
</element>

See also: descr (??) , short (??) , element (??) , seealso (??)

4.3.11  fpdoc-description : Global tag

The fpdoc-description tag is the topmost tag in a description file. It contains a series of package tags, one for each package that is described in the file.

See also: package (??)

4.3.12  i : Format italics

The i tag will cause its contents to be typeset in italics. It can occur mixed with any text.

Example:

Normal text <i>italic text</i> normal text.

will be formatted as:
Normal text italic text normal text.

See also: b (??) , u (??)

4.3.13  img : include image

The img tag will include an image in the text. It is considered equivalent to a paragraph tag. The required attribute file can be used to search to specify the filename. What kind of file is used depends on the output format. Normally, using png images should work with all output formats.

The caption attribute is optional and can be used to specify a caption text which will be displayed above or under the figure. Lastly, the name attribute can be used to attach a name to the figure (a label to which can be referred).

For example:

<p>
some text
</p>
<img file="myfile" caption="A nice caption"/>
<p>
Some more text.
</p>

See also: p (??) .

4.3.14  li : list element

The tag li denotes an element in a ol or ul list. The usage is the same as for it’s HTML counterpart: It can occur only inside one of the ol or ul list tags. It’s contents may be arbitrary text and formatting tags, contrary to HTML tags, the li tag always must have a closing tag. Note that it cannot be used in a definition list (dl (??) ).

Example:

<ul>
<li>First item in the list</li>
<li>Second item in the list</li>
</ul>

Will be typeset as

See also: ol (??) , ul (??) .

4.3.15  link : Cross-reference

The link tag is used to insert a reference to an element inside some piece of text or inside the seealso section. It is similar in functionality to the

<A HREF="SomeAnchor">some linked text</A>

construct in HTML.

The mandatory id attribute of the link tag should have the name of an element tag in it. This name is not case sensitive. FPDoc will issue a warning if it cannot find a matching name. It will look for matching names in the current file, and in all content files that have been specified with the import command-line option.

The link tag can exist in 2 forms: one with separate closing tag, surrounding a piece of text, one without separate closing tag. If a piece of text is surrounded by the link tag, then the text will be converted to a hyperlink in the HTML documentation. If there is no surrounded text, then the value of the id attribute will be used as the text. This means that

<link id="TStream">TStream</link>

and

<link id="TStream"/>

are completely equivalent.

Example:

The <link id="TStringlist">stringlist</link> class is a descendent of the
<link id="TStrings"/> class.

See also: element (??) , url (??) and the import option (section ??, page ?? ).

4.3.16  module : Unit reference

The module tag encloses all element tags for a unit. It can contain only element tags for all identifiers in the unit and a descr tag describing the unit itself. The module tag should occur inside a package tag.

The name attribute should have as a value the name of the unit which is described by the module. This name is not case sensitive.

Example:

<module name="classes">
<descr>
The classes unit contains basic class definitions for the FCL.
</descr>
</module>

See also: package (??) , descr (??) , element (??)

4.3.17  ol : Numbered list.

The ol tag starts a numbered list. It can contain only li (??) tags, which denote the various elements in the list. Each item will be preceded by a number. The ol tag can occur inside a text, but surrounding text should always be enclosed in a p (??) paragraph tag, i.e. an ol tag should occur always at the same level as a p tag.

Example:

<p> some text before</p>
<ol>
<li>First item in the list</li>
<li>Second item in the list</li>
</ol>

Will be typeset as:

some text before

  1. First item in the list.
  2. Second item in the list.

See also: li (??) , ul (??) .

4.3.18  p : Paragraph

The p tag is the paragraph tag. Every description text should be enclosed in a p tag. Only when there is only one paragraph (and no lists or tables or remarks) in a description node, then the p tag may be skipped.

Note that if a description node contains a table, pre, code or any list tag, then the text surrounding these tags must be put inside a p paragraph tag. This is different from the behaviour in HTML.

The paragraph tag must always have an opening tag and a closing tag, unlike html where only the opening tag may be present.

Example:

<descr>
This is a paragraph which need not be surrounded by paragraph tags.
</descr>
<descr>
<p>
This is the first paragraph.
</p>
<p>
This is the second paragraph.
</p>
</descr>

See also: table (??) , dl (??) , remark (??) ,code (??) , ol (??) ,ul (??) ,ol (??)

4.3.19  package : Package reference

The package tag indicates the package for which the description file contains documentation. A package is a collection of units which are logically grouped together (for a library, program, component suites). The name attribute of the package tag will be used to select the package node in the description file: Only the package node with name as specified by the package command-line option will be used when generating documentation. All other package nodes will be ignored.

The package node must always reside in a fpdoc-description node. It can contain a descr node, and various module nodes, one node per unit in the package.

See also: fpdocdescription (??) , module (??) , descr (??)

4.3.20  pre : Insert text as-is

The pre tag can be used to insert arbitrary text in the documentation. The text will not be formatted in any way, and will be displayed as it is encountered in the description node. It is functionally equivalent to the pre tag in HTML.

Note that if there is text surrounding the pre tag, it should be placed inside a p paragraph tag.

Example:

<pre>
This is some text.
  This is some more text

    And yet more text...
</pre>

This will be typeset as:

This is some text.
  This is some more text

    And yet more text...

See also: code (??) , p (??)

4.3.21  printshort : insert short description

A printshort tag can be used to insert the short description of an element in the current text. The name of the element whose short description must be printed must be given in the id attribute. Typical use for this is to repeat the elements of an enumerated type when discussion function results or possible parameter values.

Example:

<dl>
<dt>float_round_nearest_even</dt><dd><printshort id="float_round_nearest_even"/></dd>
<dt>float_round_down</dt><dd><printshort id="float_round_down"/></dd>
<dt>float_round_up</dt><dd><printshort id="float_round_up"/></dd>
<dt>float_round_to_zero</dt><dd><printshort id="float_round_to_zero"/></dd>

4.3.22  remark : format as remark

A remark tag can be used to make a paragraph stand out. The remark is equivalent to the p tag, but it’s contents is formatted in a way that makes it stand out from the rest of the text.

Note that any text before or after the remark tag must be enclosed in paragraph (p) tags.

Example:

<p>Normal text.</p>
<remark>
This text will stand out.
<example>
<p>Again normal text.</p>

Will be formatted as

Normal text.

Remark: This text will stand out.

Again normal text.

See also: p (??) , code (??) , pre (??)

4.3.23  seealso : Cross-reference section

The seealso section can occur inside any element tag, and will be used to create a list of cross-references. The contents of the seealso tag is a list of link tags. No other text is allowed inside this tag. Note that both the long and short form if the link tag may be used.

Example:

<seealso>
<link id="TStrings"/>
<link id="TStringList.Create">Create</link>
</seealso>

See also: link (??) , element (??)

4.3.24  short : Short description

The short description is used to give a short description of an identifier. If possible, the description should fit on a single line of text. The contents of this tag will be used for the following purposes:

Example:

<element name="MyEnum.meOne">
<short>First element of MyEnum</short>
</element>

See also: element (??) , descr (??)

4.3.25  table : Table start

The table tag starts a table, as in HTML. A table can contain tr (table row), th (table header row) or caption tags. Any text surrounding the table must be enclosed in paragraph tags (p).

Example:

<table>
<caption>
<var>TALignment</var> values and their meanings.
</caption>
<th><td>Value</td><td>Meaning</td></th>
<tr>
  <td><var>taLeftJustify</var></td>
  <td>Text is displayed aligned to the left.</td>
</tr>
<tr>
  <td><var>taRightJustify</var></td>
  <td>Text is displayed aligned to the right</td>
</tr>
<tr>
  <td><var>taCenter</var></td>
  <td>Text is displayed centred.</td>
</tr>
</table>

Will be formatted approximately as follows:

ValueMeaning
taLeftJustifyText is displayed aligned to the left.
taRightJustifyText is displayed aligned to the right
taCenterText is displayed centred.

See also: th (??) , caption (??) , tr (??) , p (??)

4.3.26  td : Table cell

The td tag is used to denote one cell in a table. It occurs inside a tr or th tag, and can contain any text and formatting tags.

Example:

<table>
<tr><td>Cell (1,1)</td><td>Cell (2,1)</td></tr>
<tr><td>Cell (1,2)</td><td>Cell (2,2)</td></tr>
</table>

Will be formatted approximately as

Cell (1,1)Cell (2,1)
Cell (1,2)Cell (2,2)

See also: table (??) , th (??) , tr (??)

4.3.27  th : Table header

The th table header tag is used to denote the first row(s) of a table: It (they) will be made up differently from the other rows in the table. Exactly how it is made up depends on the format. In printed documentation (latex) a line will be drawn under the row. In HTML, the font and background may be formatted differently.

The th tag can only occur inside a table tag, and can contain only td tags.

Example:

<table>
<th><td>Cell (1,1)</td><td>Cell (2,1)</td></th>
<tr><td>Cell (1,2)</td><td>Cell (2,2)</td></tr>
</table>

Will be formatted approximately as

Cell (1,1)Cell (2,1)
Cell (1,2)Cell (2,2)

See also: tr (??) , table (??)

4.3.28  topic : Topic section

The topic tag starts a topic page or section. A topic page or section is not linked to an identifier in some unit: it exists by itself. It must be inside a package or module tag. It must have a name attribute (for cross-referencing). If it appears inside a package, it can be nested: a topic may be inside another topic tag.

<module name="CRT">
<topic name="UsingKeyboard">
<short>Using the keyboard functions</short>
<descr>
To use the keyboard functions of the CRT unit, one...
</descr>
</topic>

4.3.29  tr : table row

The tr tag denotes a row in a table. It works the same as in HTML. It can occur only in a table tag, and should contain only td table data tags.

Example:

<table>
<tr><td>Cell (1,1)</td><td>Cell (2,1)</td></tr>
<tr><td>Cell (1,2)</td><td>Cell (2,2)</td></tr>
</table>

Will be formatted approximately as

Cell (1,1)Cell (2,1)
Cell (1,2)Cell (2,2)

See also: table (??) , th (??) , td (??)

4.3.30  u : Format underlined

Example:

Normal text <u>underlined text</u> normal text.

will be formatted as:
Normal text underlined text normal text.

See also: i (??) , b (??) .

4.3.31  ul : bulleted list

The ul tag starts a bulleted list. This works as under HTML, with the exception that any text surrounding the list must be enclosed in paragraph tags (p). The list elements should be enclosed in li tags.

Example:

<p> some text before</p>
<ol>
<li>First item in the list</li>
<li>Second item in the list</li>
</ol>

Will be typeset as:

some text before

See also: li (??) , ol (??) .

4.3.32  url : Hyperlink

The url tag is meant to include an URL to an arbitrary web page. It works much like the link tag, except that any URL may be specified. The attribute href specifies the URL to link to. In output formats that support links, the text in the url tag will be the link’s text. For other formats, the URL will be printed after the text.

If the url tag does not enclose any text, then the URL itself will be printed.

Examples:

The normal usage is:

<url href="http://www.freepascal.org/">Here</url> 
is the website of Free Pascal.

It will be typeset as:

Herehttp://www.freepascal.org/ is the website of Free Pascal.

The short usage is:

Check out the following site: <url href="http://www.freepascal.org/"/>.

Which will be typeset as:

Check out the following site: http://www.freepascal.org/http://www.freepascal.org/.

See also: link (??) .

4.3.33  var : variable

The var tag is used to mark a piece of text as a variable (or, more general, as an identifier). It will be typeset differently from the surrounding text. Exactly how this is done depends on the output format.

Example:

The <var>Items</var> property gives indexed access to...

Will be typeset as

The Items property gives indexed access to...

See also: b (??) , u (??) , i (??) , code (??)

4.3.34  version : version info

The version can be used to give version information: as of what version an identifier appeared or was deprecated. It should be specified below the element (??) tag, and will be output in the documentation. It can contain the same tags as the descr (??) tag, and is typeset in the same way.

The following is an example:

<element name="myenum">
<descr>
The MyEnum type is a simple enumeration type which is not
really useful, except for demonstration purposes.
</descr>
<version>The myenum type appeared in version 2.1</version>
</element>

See also: element (??) , descr (??) , errors (??) , seealso (??)

Chapter 5  Generated output files.

5.1  HTML output

The HTML output consists of the following files, per unit:

  1. A general unit description with the contents of the module’s descr tag. The uses clause is documented here as well. All units in the uses clause together with their short description tags are typeset in a table.
  2. A listing of all constants in the unit.
  3. A listing of all types in the unit (except classes).
  4. A listing of all variables in the unit.
  5. A listing of all functions/procedures in the unit.
  6. A listing of all classes in the unit.
  7. An index page per unit and per package. This is an index page, listing all top-level identifiers in the current unit or all units of the package.

All these overviews are hyperlinked to pages which contain the documentation of each identifier. Each page starts with the name of the identifier, plus a synopsis (made from the short tag’s contents). After that follows the declaration, and the description. The description is filled with the descr node of the identifiers element tag.

If an errors tag was present, an ’Errors’ section follows the description. Similarly, if there is a seealso tag, a ’See also’ section with cross-reference links is made.

For classes, the declaration contains hyperlinks to separate pages which document all the members of the class. Each member in the declaration is followed by the short tag of the member’s element tag, if one exists. As an extra, the class hierarchy is given, plus links to pop-up pages (if JavaScript is available, otherwise they are normal links) which contain alphabetical or hierarchical listings of the methods, fields or properties of the class.

For functions and procedures, the declaration will be typeset in such a way that all function arguments (if they are present) are in tabular format, followed by the short description of the argument. If it concerns a function, and a result element exists, the result description will be provided in a separate section, before the actual description.

The declaration of an enumerated type will be laid out in a table, with the enumeration value at the left, and the short description node of the value’s element.

5.2  Latex output

The latex output is in one big file with the name of the package as specified on the command line. in this file, one chapter is made per unit.

Per unit the following sections are made:

  1. A section with all constants.
  2. A section with all types.
  3. A section with all variables.
  4. A section with all functions and procedures.
  5. A section per declared class.

For the constants, types and variables, the declaration is given, followed by the descr node of the element corresponding to the identifier. All other nodes are ignored.

For functions and procedures, a subsection is made per procedure or function. This subsection consists of a list with the following entries:

Synopsis
filled with the contents of the short tag.
Declaration
Filled with the declaration of the function.
Arguments
A tabular description of all arguments, if short tags are found for them.
Description
Description of the function. Filled with the contents of the descr tag.
Errors
Description of any error conditions. Filled with the contents of the errors tag.
See Also
Cross-references to other functions. Filled with the contents of the seealso tag.

For classes, a subsection is made with an overview of implemented methods. Then a subsection is presented with available properties.

Then follows a subsection per method. These are formatted as a function, with an additional Visibility list element, giving the visibility of the function.

After the methods, a list of properties is given , formatted as a method, with an additional Access list element, specifying whether the property is read/write or not.

5.3  CHM output

The chm output in FPDoc is actually inherited from the HTML backend so everything that applies to the HTML backend applies to the chm backend, except that all generated HTML files are written directly to a stream. After all the HTML files are generated the compression is begun. Once all the auto generated files are compressed, if the –other-files option is used these files are collected and compressed. Now if the –auto-index or –auto-toc are used the Index and Table of Contents are created and the compression is finished.


This document was translated from LATEX by HEVEA.