class THtml: public TObject

The THtml class is designed to easily document classes, code, and code related text files (like change logs). It generates HTML pages conforming to the XHTML 1.0 transitional specifications; an example of these pages is ROOT's own reference guide. This page was verified to be valid XHTML 1.0 transitional, which proves that all pages generated by THtml can be valid, as long as the user provided XHTML (documentation, header, etc) is valid. You can check the current THtml by clicking this icon:

Overview:

1. Usage
2. Configuration
   1. Input files
   2. Output directory
   3. Linking other documentation
   4. Recognizing class documentation
   5. Author, copyright, etc.
   6. Header and footer
   7. Links to searches, home page, ViewVC
   8. HTML Charset
3. Documentation syntax
   1. Class description
   2. Class index
   3. Method documentation
   4. Data member documentation
4. Documentation directives
   1. BEGIN_HTML END_HTML: include 'raw' HTML
   2. BEGIN_MACRO END_MACRO: include a picture generated by a macro
   3. BEGIN_LATEX END_LATEX: include a latex picture
5. Product and module index
6. Auxiliary files: style sheet, JavaScript, help page
7. Class Charts
8. Configuration variables
9. Behind the scenes

I. Usage

These are typical things people do with THtml:

    root[] THtml html;                // create a THtml object
    root[] html.MakeAll();             // generate documentation for all changed classes

or to run on just a few classes:

    root[] THtml html;                // create a THtml object
    root[] html.MakeIndex();           // create auxilliary files (style sheet etc) and indices
    root[] html.MakeClass("TMyClass"); // create documentation for TMyClass only

To "beautify" (i.e. create links to documentation for class names etc) some text file or macro, use:

    root[] html.Convert( "hsimple.C", "Histogram example" )

II. Configuration

Most configuration options can be set as a call to THtml, or as a TEnv variable, which you can set in your .rootrc.

II.1 Input files

In your .rootrc, define Root.Html.SourceDir to point to directories containing .cxx and .h files (see: TEnv) of the classes you want to document, or call THtml::SetInputDir()

Example:

  Root.Html.SourceDir:  .:src:include
  Root.Html.Root:       http://root.cern.ch/root/html

II.2 Output directory

The output directory can be specified using the Root.Html.OutputDir configuration variable (default value: "htmldoc"). If that directory doesn't exist THtml will create it.

Example:

  Root.Html.OutputDir:         htmldoc

II.3 Linking other documentation

When trying to document a class, THtml searches for a source file in the directories set via SetInputDir(). If it cannot find it, it assumes that this class must have been documented before. Based on the library this class is defined in, it checks the configuration variable Root.Html.LibName, and creates a link using its value. Alternatively, you can set these URLs via THtml::SetLibURL().

Example:
If a class MyClass is defined in class mylibs/libMyLib.so, and .rootrc contains

  Root.Html.MyLib: ../mylib/

THtml will create a link to "../mylib/MyClass.html".

The library name association can be set up using the rootmap facility. For the library in the example above, which contains a dictionary generated from the linkdef MyLinkdef.h, the command to generate the rootmap file is

  $ rlibmap -f -r rootmap -l mylib/libMyLib.so -d libCore.so -c MyLinkdef.h

Here, -r specifies that the entries for libMyLib should be updated, -l specifies the library we're dealing with, -d its dependencies, and -c its linkdef. The rootmap file must be within one of the LD_LIBRARY_PATH (or PATH for Windows) directories when ROOT is started, otherwise ROOT will not use it.

II.4 Recognizing class documentation

The class documentation has to appear in the header file containing the class, right in front of its declaration. It is introduced by a string defined by Root.Html.Description or SetClassDocTag(). See the section on documentation syntax for further details.

Example:

  Root.Html.Description:       //____________________

The class documentation will show which include statement is to be used and which library needs to be linked to access it. The include file name is determined via TClass::GetDeclFileName(); leading parts are removed if they match any of the ':' separated entries in THtml::GetIncludePath().

II.5 Author, copyright, etc.

During the conversion, THtml will look for some strings ("tags") in the source file, which have to appear right in front of e.g. the author's name, copyright notice, etc. These tags can be defined with the following environment variables: Root.Html.Author, Root.Html.LastUpdate and Root.Html.Copyright, or with SetAuthorTag(), SetLastUpdateTag(), SetCopyrightTag().

If the LastUpdate tag is not found, the current date and time are used. This is useful when using THtml::MakeAll()'s default option force=kFALSE, in which case THtml generates documentation only for changed classes.

Authors can be a comma separated list of author entries. Each entry has one of the following two formats

• Name (non-alpha).

  THtml will generate an HTML link for Name, taking the Root.Html.XWho configuration variable (defaults to "http://consult.cern.ch/xwho/people?") and adding all parts of the name with spaces replaces by '+'. Non-alphanumerical characters are printed out behind Name.

  Example:

  // Author: Enrico Fermi appears in the source file. THtml will generate the link http://consult.cern.ch/xwho/people?Enrico+Fermi. This works well for people at CERN.
• Name <link> Info.

  THtml will generate an HTML link for Name as specified by link and print Info behind Name.

  Example:

  // Author: Enrico Fermi <http://www.enricos-home.it> or
  // Author: Enrico Fermi <mailto:enrico@fnal.gov> in the source file. That's world compatible.

Example (with defaults given):

      Root.Html.Author:     // Author:
      Root.Html.LastUpdate: // @(#)
      Root.Html.Copyright:  * Copyright
      Root.Html.XWho:       http://consult.cern.ch/xwho/people?

II.6 Header and footer

THtml generates a default header and footer for all pages. You can specify your own versions with the configuration variables Root.Html.Header and Root.Html.Footer, or by calling SetHeader(), SetFooter(). Both variables default to "", using the standard Root versions. If it has a "+" appended, THtml will write both versions (user and root) to a file, for the header in the order 1st root, 2nd user, and for the footer 1st user, 2nd root (the root versions containing "<html>" and </html> tags, resp).

If you want to replace root's header you have to write a file containing all HTML elements necessary starting with the <doctype> tag and ending with (and including) the <body> tag. If you add your header it will be added directly after Root's <body> tag. Any occurrence of the string %TITLE% in the user's header file will be replaced by a sensible, automatically generated title. If the header is generated for a class, occurrences of %CLASS% will be replaced by the current class's name, %SRCFILE% and %INCFILE% by the name of the source and header file, resp. (as given by TClass::GetImplFileName(), TClass::GetDeclFileName()). If the header is not generated for a class, they will be replaced by "".

Root's footer starts with the tag <!--SIGNATURE-->. It includes the author(s), last update, copyright, the links to the Root home page, to the user home page, to the index file (ClassIndex.html), to the top of the page and this page is automatically generated infomation. It ends with the tags </body></html>. If you want to replace it, THtml will search for some tags in your footer: Occurrences of the strings %AUTHOR%, %UPDATE%, and %COPYRIGHT% are replaced by their corresponding values before writing the html file. The %AUTHOR% tag will be replaced by the exact string that follows Root.Html.Author, no link generation will occur.

II.7 Links to searches, home page, ViewVC

Additional parameters can be set by Root.Html.Homepage (address of the user's home page), Root.Html.SearchEngine (search engine for the class documentation), Root.Html.Search (search URL, where %u is replaced by the referer and %s by the escaped search expression), and a ViewVC base URL Root.Html.ViewCVS. For the latter, the file name is appended or, if the URL contains %f, %f is replaced by the file name. All values default to "".

Examples:

      Root.Html.Homepage:     http://www.enricos-home.it
      Root.Html.SearchEngine: http://root.cern.ch/root/Search.phtml
      Root.Html.Search:       http://www.google.com/search?q=%s+site%3A%u

II.8 HTML Charset

XHTML 1.0 transitional recommends the specification of the charset in the content type meta tag, see e.g. http://www.w3.org/TR/2002/REC-xhtml1-20020801/ THtml generates it for the HTML output files. It defaults to ISO-8859-1, and can be changed using Root.Html.Charset.

Example:

      Root.Html.Charset:      EUC-JP

III. Documentation syntax

III.1 Class description

A class description block, which must be placed before the first member function, has a following form:

////////////////////////////////////////////////////////////////
//                                                            //
// TMyClass                                                   //
//                                                            //
// This is the description block.                             //
//                                                            //
////////////////////////////////////////////////////////////////

The environment variable Root.Html.Description (see: TEnv) contains the delimiter string (default value: //_________________). It means that you can also write your class description block like this:

   //_____________________________________________________________
   // A description of the class starts with the line above, and
   // will take place here !
   //

Note that everything until the first non-commented line is considered as a valid class description block.

III.2 Class index

All classes to be documented will have an entry in the ClassIndex.html, showing their name with a link to their documentation page and a miniature description. This discription for e.g. the class MyClass has to be given in MyClass's header as a comment right after ClassDef(MyClass, n).

III.3 Method documentation

A member function description block starts immediately after '{' and looks like this:

   void TWorld::HelloWorldFunc(string *text)
   {
      // This is an example of description for the
      // TWorld member function
      helloWorld.Print( text );
   }

Like in a class description block, everything until the first non-commented line is considered as a valid member function description block. If the rootrc variable Root.Html.DescriptionStyle is set to Doc++ THtml will also look for method documentation in front of the function implementation. This feature is not recommended; source code making use of this does not comply to the ROOT documentation standards, which means future versions of THtml might not support it anymore.

III.4 Data member documentation

Data members are documented by putting a C++ comment behind their declaration in the header file, e.g.

   int fIAmADataMember; // this is a data member

IV. Documentation directives

NOTE that THtml does not yet support nested directives (i.e. latex inside html etc)!

IV.1 BEGIN_HTML END_HTML: include 'raw' HTML

You can insert pure html code into your documentation comments. During the generation of the documentation, this code will be inserted as is into the html file.

Pure html code must be surrounded by the keywords BEGIN_HTML and END_HTML, where the case is ignored. An example of pure html code is this class description you are reading right now. THtml uses a TDocHtmlDirective object to process this directive.

IV.2 BEGIN_MACRO END_MACRO: include a picture generated by a macro

THtml can create images from scripts. You can either call an external script by surrounding it by "begin_macro"/"end_macro", or include an unnamed macro within these keywords. The macro should return a pointer to an object; this object will then be saved as a GIF file.

Objects deriving from TGObject (GUI elements) will need to run in graphics mode (non-batch). You must specify this as a parameter: "Begin_macro(GUI)...". To create a second tab that displays the source of the macro you can specify the argument "Begin_macro(source)...". Of course you can combine them, e.g. as "Begin_macro(source,gui)...". THtml uses a TDocMacroDirective object to process this directive.

This is an example:

IV.3 BEGIN_LATEX END_LATEX: include a latex picture

You can specify TLatex style text and let THtml convert it into an image by surrounding it by "Begin_Latex", "End_Latex". You can have multiple lines, and e.g. align each line at the '=' sign by passing the argument separator='='. You can also specify how to align these parts; if you want the part left of the separator to be right aligned, and the right part to be left aligned, you could specify align='rl'. THtml uses a TDocLatexDirective object to process the directive. This is an example output with arguments separator='=', align='rl':

V. Product and module index

THtml::MakeIndex() will generate index files for classes and types, all modules, and the product which you can set by THtml::SetProductName(). THtml will make use of external documentation in the module and product index, either by linking it or by including it. The files for modules are searched based on the source file directory of the module's classes.

A filename starting with "index." will be included in the index page; all other files will be linked. Only files ending on .html or .txt will be taken into account; the text files will first be run through THtml::Convert(). You can see an example here; the part between "Index of HIST classes" and "Jump to" is created by parsing the module's doc directory.

VI. Auxiliary files: style sheet, JavaScript, help page

The documentation pages share a common set of javascript and CSS files. They are generated automatically when running MakeAll(); they can be generated on demand by calling CreateAuxiliaryFiles().

VII. Class Charts

THtml can generate a number of graphical representations for a class, which are displayed as a tabbed set of imaged ontop of the class description. It can show the inheritance, inherited and hidden members, directly and indirectly included files, and library dependencies. These graphs are generated using the Graphviz package. You can install it from http://www.graphviz.org. You can either put it into your $PATH, or tell THtml where to find it by calling SetDotDir().

VIII. Configuration variables

Here is a list of all configuration variables that are known to THtml. You can set them in your .rootrc file, see TEnv.

  Root.Html.OutputDir    (default: htmldoc)
  Root.Html.SourceDir    (default: .:src/:include/)
  Root.Html.Author       (default: // Author:) - start tag for authors
  Root.Html.LastUpdate   (default: // @(#)) - start tag for last update
  Root.Html.Copyright    (default:  * Copyright) - start tag for copyright notice
  Root.Html.Description  (default: //____________________ ) - start tag for class descr
  Root.Html.HomePage     (default: ) - URL to the user defined home page
  Root.Html.Header       (default: ) - location of user defined header
  Root.Html.Footer       (default: ) - location of user defined footer
  Root.Html.Root         (default: ) - URL of Root's class documentation
  Root.Html.SearchEngine (default: ) - link to the search engine
  Root.Html.Search       (defualt: ) - link to search by replacing "%s" with user input
  Root.Html.ViewCVS      (default: ) - URL of ViewCVS base
  Root.Html.XWho         (default: http://consult.cern.ch/xwho/people?) - URL of CERN's xWho
  Root.Html.Charset      (default: ISO-8859-1) - HTML character set

IX. Behind the scene

Internally, THtml is just an API class that sets up the list of known classes, and forwards API invocations to the "work horses". TDocOutput generates the output by letting a TDocParser object parse the sources, which in turn invokes objects deriving from TDocDirective to process directives.