[comment {-*- tcl -*- doctools manpage}]
[manpage_begin doctools::idx n 2.1]
[keywords conversion]
[keywords {docidx markup}]
[keywords documentation]
[keywords formatting]
[keywords generation]
[keywords HTML]
[keywords index]
[keywords json]
[keywords {keyword index}]
[keywords latex]
[keywords manpage]
[keywords markup]
[keywords nroff]
[keywords parsing]
[keywords plugin]
[keywords reference]
[keywords {tcler's wiki}]
[keywords text]
[keywords TMML]
[keywords url]
[keywords wiki]
[copyright {2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>}]
[moddesc   {Documentation tools}]
[titledesc {Holding keyword indices}]
[category  {Documentation tools}]
[require doctools::idx [opt 2.1]]
[require Tcl "8.5 9"]
[require doctools::idx::structure]
[require snit]
[description]

This package provides a class to contain and programmatically
manipulate keyword indices

[para]

This is one of the three public pillars the management of keyword
indices resides on. The other two pillars are

[list_begin enum]
[enum] [manpage {Exporting keyword indices}], and
[enum] [manpage {Importing keyword indices}]
[list_end]

[para]

For information about the [sectref Concepts] of keyword indices, and
their parts, see the same-named section.

For information about the data structure which is used to encode
keyword indices as values see the section
[sectref {Keyword index serialization format}].

This is the only format directly known to this class. Conversions from
and to any other format are handled by export and import manager
objects. These may be attached to a container, but do not have to be,
it is merely a convenience.

[section Concepts] [include include/concept.inc]

[section API]
[subsection {Package commands}]

[list_begin definitions]

[call [cmd ::doctools::idx] [arg objectName]]

This command creates a new container object with an associated Tcl
command whose name is [arg objectName]. This [term object] command is
explained in full detail in the sections [sectref {Object command}]
and [sectref {Object methods}]. The object command will be created
under the current namespace if the [arg objectName] is not fully
qualified, and in the specified namespace otherwise.

[list_end]

[subsection {Object command}]

All objects created by the [cmd ::doctools::idx] command have the
following general form:

[list_begin definitions]

[call [cmd objectName] [method method] [opt [arg "arg arg ..."]]]

The method [method method] and its [arg arg]'uments determine the
exact behavior of the command.

See section [sectref {Object methods}] for the detailed
specifications.

[list_end]

[subsection {Object methods}]

[list_begin definitions]

[call [arg objectName] [method destroy]]

This method destroys the object it is invoked for.

[call [arg objectName] [method {key add}] [arg name]]

This method adds the keyword [arg name] to the index. If the keyword
is already known nothing is done. The result of the method is the
empty string.

[call [arg objectName] [method {key remove}] [arg name]]

This method removes the keyword [arg name] from the index. If the
keyword is already gone nothing is done. Any references for whom this
keyword was the last association are removed as well.  The result of
the method is the empty string.

[call [arg objectName] [method {key references}] [arg name]]

This method returns a list containing the names of all references
associated with the keyword [arg name]. An error is thrown in the
keyword is not known to the index. The order of the references in the
list is undefined.

[call [arg objectName] [method keys]]

This method returns a list containing the names of all keywords known
to the index. The order of the keywords in the list is undefined.

[call [arg objectName] [method {reference add}] [arg type] [arg key] [arg name] [arg label]]

This method adds the reference [arg name] to the index and associates
it with the keyword [arg key].

The other two arguments hold the [arg type] and [arg label] of the
reference, respectively.

The type has to match the stored information, should the reference
exist already, i.e. this information is immutable after the reference
is known. The only way to change it is delete and recreate the
reference.

The label on the other hand is automatically updated to the value of
the argument, overwriting any previously stored information.

Should the reference exists already it is simply associated with the
[arg key].  If that is true already as well nothing is done, but the
[arg label] updated to the new value.  The result of the method is the
empty string.

[para]

The [arg type] argument has be to one of [const manpage] or [const url].

[call [arg objectName] [method {reference remove}] [arg name]]

The reference [arg name] is removed from the index. All associations
with keywords are released and the relevant reference labels removed.
The result of the method is the empty string.

[call [arg objectName] [method {reference label}] [arg name]]

This method returns the label associated with the reference
[arg name]. An error is thrown if the reference is not known.

[call [arg objectName] [method {reference keys}] [arg name]]

This method returns a list containing the names of all keywords
associated with the reference [arg name]. An error is thrown in the
reference is not known to the index. The order of the keywords in the
list is undefined.

[call [arg objectName] [method {reference type}] [arg name]]

This method returns the type of the reference [arg name]. An error is
thrown in the reference is not known to the index.

[call [arg objectName] [method references]]

This method returns a list containing the names of all references
known to the index. The order of the references in the list is
undefined.

[call [arg objectName] [method title]]

Returns the currently defined title of the keyword index.

[call [arg objectName] [method title] [arg text]]

Sets the title of the keyword index to [arg text], and returns it as
the result of the command.

[call [arg objectName] [method label]]

Returns the currently defined label of the keyword index.

[call [arg objectName] [method label] [arg text]]

Sets the label of the keyword index to [arg text], and returns it as
the result of the command.

[call [arg objectName] [method importer]]

Returns the import manager object currently attached to the container,
if any.

[call [arg objectName] [method importer] [arg object]]

Attaches the [arg object] as import manager to the container, and
returns it as the result of the command.

Note that the [arg object] is [emph not] put into ownership of the
container. I.e., destruction of the container will [emph not] destroy
the [arg object].

[para]

It is expected that [arg object] provides a method named
[method {import text}] which takes a text and a format name, and
returns the canonical serialization of the keyword index contained in
the text, assuming the given format.

[call [arg objectName] [method exporter]]

Returns the export manager object currently attached to the container,
if any.

[call [arg objectName] [method exporter] [arg object]]

Attaches the [arg object] as export manager to the container, and
returns it as the result of the command.

Note that the [arg object] is [emph not] put into ownership of the
container. I.e., destruction of the container will [emph not] destroy
the [arg object].

[para]

It is expected that [arg object] provides a method named
[method {export object}] which takes the container and a format name,
and returns a text encoding keyword index stored in the container, in
the given format. It is further expected that the [arg object] will
use the container's method [method serialize] to obtain the
serialization of the keyword index from which to generate the text.

[call [arg objectName] [method {deserialize =}] [arg data] [opt [arg format]]]

This method replaces the contents of the index object with the index
contained in the [arg data]. If no [arg format] was specified it is
assumed to be the regular serialization of a keyword index.

[para]

Otherwise the object will use the attached import manager to convert
the data from the specified format to a serialization it can handle.

In that case an error will be thrown if the container has no import
manager attached to it.

[para]

The result of the method is the empty string.

[call [arg objectName] [method {deserialize +=}] [arg data] [opt [arg format]]]

This method behaves like [method {deserialize =}] in its essentials,
except that it merges the keyword index in the [arg data] to its
contents instead of replacing it.

The method will throw an error if merging is not possible, i.e. would
produce an invalid index. The existing content is left unchanged in
that case.

[para]

The result of the method is the empty string.

[call [arg objectName] [method serialize] [opt [arg format]]]

This method returns the keyword index contained in the object. If no
[arg format] is not specified the returned result is the canonical
serialization of its contents.

[para]

Otherwise the object will use the attached export manager to convert
the data to the specified format.

In that case an error will be thrown if the container has no export
manager attached to it.

[list_end]

[include include/serialization.inc]
[vset CATEGORY doctools]
[include ../common-text/feedback.inc]
[manpage_end]
