# doctools::idx(3tcl) 1.2.1 doctools "Documentation tools"

## Name

doctools::idx - docidx - Processing indices

## Synopsis

- package require Tcl 8.5 9
- package require doctools::idx ?1.2.1?

- ::doctools::idx::new objectName ?-option value ...?
- ::doctools::idx::help
- ::doctools::idx::search path
- objectName method ?arg arg ...?
- objectName configure
- objectName configure option
- objectName configure -option value...
- objectName cget -option
- objectName destroy
- objectName format text
- objectName map symbolic actual
- objectName parameters
- objectName search path
- objectName setparam name value
- objectName warnings

## Description

This package provides a class for the creation of objects able to process and convert text written in the docidx markup language into any output format X for which a formatting engine is available.

A reader interested in the markup language itself should start with the docidx language introduction and proceed from there to the formal specifications, i.e. the docidx language syntax and the docidx language command reference.

If on the other hand the reader wishes to write her own formatting engine for some format, i.e. is a plugin writer then reading and understanding the docidx plugin API reference is an absolute necessity, as that document specifies the interaction between this package and its plugins, i.e. the formatting engines, in detail.

## PUBLIC API

### PACKAGE COMMANDS

::doctools::idx::new objectName ?-option value ...?

  This command creates a new docidx object with an associated Tcl command whose name is objectName. This object command is explained in full detail in the sections OBJECT COMMAND and OBJECT METHODS. The object command will be created under the current namespace if the objectName is not fully qualified, and in the specified namespace otherwise.

  The options and their values coming after the name of the object are used to set the initial configuration of the object.

::doctools::idx::help

  This is a convenience command for applications wishing to provide their user with a short description of the available formatting commands and their meanings. It returns a string containing a standard help text.

::doctools::idx::search path

  Whenever an object created by this the package has to map the name of a format to the file containing the code for its formatting engine it will search for the file in a number of directories stored in a list. See section FORMAT MAPPING for more explanations.

  This list not only contains three default directories which are declared by the package itself, but is also extensible user of the package. This command is the means to do so. When given a path to an existing and readable directory it will prepend that directory to the list of directories to search. This means that the path added last is later searched through first.

  An error will be thrown if the path either does not exist, is not a directory, or is not readable.

### OBJECT COMMAND

All commands created by ::doctools::idx::new have the following general form and may be used to invoke various operations on their docidx converter object.

objectName method ?arg arg ...?

  The method method and its arg'uments determine the exact behavior of the command. See section OBJECT METHODS for the detailed specifications.

### OBJECT METHODS

objectName configure

  The method returns a list of all known options and their current values when called without any arguments.

objectName configure option

  The method behaves like the method cget when called with a single argument and returns the value of the option specified by said argument.

objectName configure -option value...

  The method reconfigures the specified options of the object, setting them to the associated values, when called with an even number of arguments, at least two.

  The legal options are described in the section OBJECT CONFIGURATION.

objectName cget -option

  This method expects a legal configuration option as argument and will return the current value of that option for the object the method was invoked for.

  The legal configuration options are described in section OBJECT CONFIGURATION.

objectName destroy

  This method destroys the object it is invoked for.

objectName format text

  This method runs the text through the configured formatting engine and returns the generated string as its result. An error will be thrown if no -format was configured for the object.

  The method assumes that the text is in docidx format as specified in the companion document docidx_fmt. Errors will be thrown otherwise.

objectName map symbolic actual

  This methods add one entry to the per-object mapping from symbolic filenames to the actual uris. The object just stores this mapping and makes it available to the configured formatting engine through the command dt_fmap. This command is described in more detail in the docidx plugin API reference which specifies the interaction between the objects created by this package and index formatting engines.

objectName parameters

  This method returns a list containing the names of all engine parameters provided by the configured formatting engine. It will return an empty list if the object is not yet configured for a specific format.

objectName search path

  This method extends the per-object list of paths searched for index formatting engines. See also the command ::doctools::idx::search on how to extend the per-package list of paths. Note that the path entered last will be searched first. For more details see section FORMAT MAPPING.

objectName setparam name value

  This method sets the named engine parameter to the specified value. It will throw an error if the object is either not yet configured for a specific format, or if the formatting engine for the configured format does not provide a parameter with the given name. The list of parameters provided by the configured formatting engine can be retrieved through the method parameters.

objectName warnings

  This method returns a list containing all the warnings which were generated by the configured formatting engine during the last invocation of the method format.

### OBJECT CONFIGURATION

All docidx objects understand the following configuration options:

-file file

  The argument of this option is stored in the object and made available to the configured formatting engine through the command dt_file. This command is described in more detail in the companion document docidx_api which specifies the API between the object and formatting engines.

  The default value of this option is the empty string.

  The configured formatting engine should interpret the value as the name of the file containing the document which is currently processed.

-format text

  The argument of this option specifies the format to generate and by implication the formatting engine to use when converting text via the method format. Its default value is the empty string. The method format cannot be used if this option is not set to a valid value at least once.

  The package will immediately try to map the given name to a file containing the code for a formatting engine generating that format. An error will be thrown if this mapping fails. In that case a previously configured format is left untouched.

  The section FORMAT MAPPING explains in detail how the package and object will look for engine implementations.

### FORMAT MAPPING

The package and object will perform the following algorithm when trying to map a format name foo to a file containing an implementation of a formatting engine for foo:

1. If foo is the name of an existing file then this file is directly taken as the implementation.

2. If not, the list of per-object search paths is searched. For each directory in the list the package checks if that directory contains a file "idx.foo". If yes, then that file is taken as the implementation.

   Note that this list of paths is initially empty and can be extended through the object method search.

3. If not, the list of package paths is searched. For each directory in the list the package checks if that directory contains a file "idx.foo". If yes, then that file is taken as the implementation.

   This list of paths can be extended through the command ::doctools::idx::search. It contains initially one path, the subdirectory "mpformats" of the directory the package itself is located in. In other words, if the package implementation "docidx.tcl" is installed in the directory "/usr/local/lib/tcllib/doctools" then it will by default search the directory "/usr/local/lib/tcllib/doctools/mpformats" for format implementations.

4. The mapping fails.

## PREDEFINED ENGINES

The package provides predefined formatting engines for the following formats. Some of the formatting engines support engine parameters. These will be explicitly highlighted.

html

  This engine generates HTML markup, for processing by web browsers and the like. This engine supports three parameters:

  footer

    The value for this parameter has to be valid selfcontained HTML markup for the body section of a HTML document. The default value is the empty string. The value is inserted into the generated output just before the </body> tag, closing the body of the generated HTML.

    This can be used to insert boilerplate footer markup into the generated document.

  header

    The value for this parameter has to be valid selfcontained HTML markup for the body section of a HTML document. The default value is the empty string. The value is inserted into the generated output just after the <body> tag, starting the body of the generated HTML.

    This can be used to insert boilerplate header markup into the generated document.

  meta

    The value for this parameter has to be valid selfcontained HTML markup for the header section of a HTML document. The default value is the empty string. The value is inserted into the generated output just after the <head> tag, starting the header section of the generated HTML.

    This can be used to insert boilerplate meta data markup into the generated document, like references to a stylesheet, standard meta keywords, etc.

latex

  This engine generates output suitable for the latex text processor coming out of the TeX world.

list

  This engine retrieves version, section and title of the manpage from the document. As such it can be used to generate a directory listing for a set of manpages.

markdown

  This engine generates Markdown markup.

nroff

  This engine generates nroff output, for processing by nroff, or groff. The result will be standard man pages as they are known in the unix world.

null

  This engine generates no outout at all. This can be used if one just wants to validate some input.

tmml

  This engine generates TMML markup as specified by Joe English. The Tcl Manpage Markup Language is a derivate of XML.

wiki

  This engine generates Wiki markup as understood by Jean Claude Wippler's wikit application.

## Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category doctools of the Tcllib Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide unified diffs, i.e the output of diff -u.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar.

## See Also

docidx_intro, docidx_lang_cmdref, docidx_lang_intro, docidx_lang_syntax, docidx_plugin_apiref

## Keywords

HTML, TMML, conversion, docidx, documentation, index, keyword index, latex, manpage, markdown, markup, nroff, wiki

## Category

Documentation tools

## Copyright

Copyright © 2003-2019 Andreas Kupries <andreas_kupries@users.sourceforge.net>