Provided by: tcllib_1.21+dfsg-1_all 
NAME
doctools::toc::export - Exporting tables of contents
SYNOPSIS
package require doctools::toc::export ?0.2.1?
package require Tcl 8.4
package require struct::map
package require doctools::toc::structure
package require snit
package require pluginmgr
::doctools::toc::export objectName
objectName method ?arg arg ...?
objectName destroy
objectName export serial serial ?format?
objectName export object object ?format?
objectName config names
objectName config get
objectName config set name ?value?
objectName config unset pattern...
export serial configuration
_________________________________________________________________________________________________
DESCRIPTION
This package provides a class to manage the plugins for the export of tables of contents
to other formats, i.e. their conversion to, for example doctoc, HTML, etc.
This is one of the three public pillars the management of tables of contents resides on.
The other two pillars are
[1] Importing tables of contents, and
[2] Holding tables of contents
For information about the Concepts of tables of contents, and their parts, see the same-
named section. For information about the data structure which is the major input to the
manager objects provided by this package see the section ToC serialization format.
The plugin system of our class is based on the package pluginmgr, and configured to look
for plugins using
[1] the environment variable DOCTOOLS_TOC_EXPORT_PLUGINS,
[2] the environment variable DOCTOOLS_TOC_PLUGINS,
[3] the environment variable DOCTOOLS_PLUGINS,
[4] the path "~/.doctools/toc/export/plugin"
[5] the path "~/.doctools/toc/plugin"
[6] the path "~/.doctools/plugin"
[7] the path "~/.doctools/toc/export/plugins"
[8] the path "~/.doctools/toc/plugins"
[9] the path "~/.doctools/plugins"
[10] the registry entry "HKEY_CURRENT_USER\SOFTWARE\DOCTOOLS\TOC\EXPORT\PLUGINS"
[11] the registry entry "HKEY_CURRENT_USER\SOFTWARE\DOCTOOLS\TOC\PLUGINS"
[12] the registry entry "HKEY_CURRENT_USER\SOFTWARE\DOCTOOLS\PLUGINS"
The last three are used only when the package is run on a machine using Windows(tm)
operating system.
The whole system is delivered with six predefined export plugins, namely
doctoc See doctoc export plugin for details.
html See html export plugin for details.
json See json export plugin for details.
nroff See nroff export plugin for details.
text See text export plugin for details.
wiki See wiki export plugin for details.
Readers wishing to write their own export plugin for some format, i.e. plugin writers
reading and understanding the section containing the Export plugin API v2 reference is an
absolute necessity, as it specifies the interaction between this package and its plugins
in detail.
CONCEPTS
[1] A table of contents consists of a (possibly empty) list of elements.
[2] Each element in the list is identified by its label.
[3] Each element is either a reference, or a division.
[4] Each reference has an associated document, identified by a symbolic id, and a
textual description.
[5] Each division may have an associated document, identified by a symbolic id.
[6] Each division consists consists of a (possibly empty) list of elements, with each
element following the rules as specified in item 2 and above.
A few notes
[1] The above rules span up a tree of elements, with references as the leaf nodes, and
divisions as the inner nodes, and each element representing an entry in the whole
table of contents.
[2] The identifying labels of any element E are unique within their division (or toc),
and the full label of any element E is the list of labels for all nodes on the
unique path from the root of the tree to E, including E.
API
PACKAGE COMMANDS
::doctools::toc::export objectName
This command creates a new export manager 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.
OBJECT COMMAND
All objects created by the ::doctools::toc::export command have the following general
form:
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 destroy
This method destroys the object it is invoked for.
objectName export serial serial ?format?
This method takes the canonical serialization of a table of contents stored in
serial and converts it to the specified format, using the export plugin for the
format. An error is thrown if no plugin could be found for the format. The string
generated by the conversion process is returned as the result of this method.
If no format is specified the method defaults to doctoc.
The specification of what a canonical serialization is can be found in the section
ToC serialization format.
The plugin has to conform to the interface specified in section Export plugin API
v2 reference.
objectName export object object ?format?
This method is a convenient wrapper around the export serial method described by
the previous item. It expects that object is an object command supporting a
serialize method returning the canonical serialization of a table of contents. It
invokes that method, feeds the result into export serial and returns the resulting
string as its own result.
objectName config names
This method returns a list containing the names of all configuration variables
currently known to the object.
objectName config get
This method returns a dictionary containing the names and values of all
configuration variables currently known to the object.
objectName config set name ?value?
This method sets the configuration variable name to the specified value and returns
the new value of the variable.
If no value is specified it simply returns the current value, without changing it.
Note that while the user can set the predefined configuration variables user and
format doing so will have no effect, these values will be internally overridden
when invoking an import plugin.
objectName config unset pattern...
This method unsets all configuration variables matching the specified glob
patterns. If no pattern is specified it will unset all currently defined
configuration variables.
EXPORT PLUGIN API V2 REFERENCE
Plugins are what this package uses to manage the support for any output format beyond the
ToC serialization format. Here we specify the API the objects created by this package use
to interact with their plugins.
A plugin for this package has to follow the rules listed below:
[1] A plugin is a package.
[2] The name of a plugin package has the form doctools::toc::export::FOO, where FOO is
the name of the format the plugin will generate output for. This name is also the
argument to provide to the various export methods of export manager objects to get
a string encoding a table of contents in that format.
[3] The plugin can expect that the package doctools::toc::export::plugin is present, as
indicator that it was invoked from a genuine plugin manager.
[4] A plugin has to provide one command, with the signature shown below.
export serial configuration
Whenever an export manager of doctools::toc has to generate output for a
table of contents it will invoke this command.
string serial
This argument will contain the canonical serialization of the table
of contents for which to generate the output. The specification of
what a canonical serialization is can be found in the section ToC
serialization format.
dictionary configuration
This argument will contain the current configuration to apply to the
generation, as a dictionary mapping from variable names to values.
The following configuration variables have a predefined meaning all
plugins have to obey, although they can ignore this information at
their discretion. Any other other configuration variables recognized
by a plugin will be described in the manpage for that plugin.
user This variable is expected to contain the name of the user
owning the process invoking the plugin.
format This variable is expected to contain the name of the format
whose plugin is invoked.
file This variable, if defined by the user of the table object is
expected to contain the name of the input file for which the
plugin is generating its output for.
map This variable, if defined by the user of the table object is
expected to contain a dictionary mapping from symbolic
document ids used in the table entries to actual paths (or
urls). A plugin has to be able to handle the possibility that
a document id is without entry in this mapping.
[5] A single usage cycle of a plugin consists of the invokations of the command export.
This call has to leave the plugin in a state where another usage cycle can be run
without problems.
TOC SERIALIZATION FORMAT
Here we specify the format used by the doctools v2 packages to serialize tables of
contents as immutable values for transport, comparison, etc.
We distinguish between regular and canonical serializations. While a table of contents
may have more than one regular serialization only exactly one of them will be canonical.
regular serialization
[1] The serialization of any table of contents is a nested Tcl dictionary.
[2] This dictionary holds a single key, doctools::toc, and its value. This value
holds the contents of the table of contents.
[3] The contents of the table of contents are a Tcl dictionary holding the title
of the table of contents, a label, and its elements. The relevant keys and
their values are
title The value is a string containing the title of the table of contents.
label The value is a string containing a label for the table of contents.
items The value is a Tcl list holding the elements of the table, in the
order they are to be shown.
Each element is a Tcl list holding the type of the item, and its
description, in this order. An alternative description would be that
it is a Tcl dictionary holding a single key, the item type, mapped to
the item description.
The two legal item types and their descriptions are
reference
This item describes a single entry in the table of contents,
referencing a single document. To this end its value is a Tcl
dictionary containing an id for the referenced document, a
label, and a longer textual description which can be
associated with the entry. The relevant keys and their values
are
id The value is a string containing the id of the document
associated with the entry.
label The value is a string containing a label for this
entry. This string also identifies the entry, and no
two entries (references and divisions) in the
containing list are allowed to have the same label.
desc The value is a string containing a longer description
for this entry.
division
This item describes a group of entries in the table of
contents, inducing a hierarchy of entries. To this end its
value is a Tcl dictionary containing a label for the group, an
optional id to a document for the whole group, and the list of
entries in the group. The relevant keys and their values are
id The value is a string containing the id of the document
associated with the whole group. This key is optional.
label The value is a string containing a label for the group.
This string also identifies the entry, and no two
entries (references and divisions) in the containing
list are allowed to have the same label.
items The value is a Tcl list holding the elements of the
group, in the order they are to be shown. This list
has the same structure as the value for the keyword
items used to describe the whole table of contents, see
above. This closes the recusrive definition of the
structure, with divisions holding the same type of
elements as the whole table of contents, including
other divisions.
canonical serialization
The canonical serialization of a table of contents has the format as specified in
the previous item, and then additionally satisfies the constraints below, which
make it unique among all the possible serializations of this table of contents.
[1] The keys found in all the nested Tcl dictionaries are sorted in ascending
dictionary order, as generated by Tcl's builtin command lsort -increasing
-dict.
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
[http://core.tcl.tk/tcllib/reportlist]. 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.
KEYWORDS
HTML, conversion, doctoc, documentation, export, formatting, generation, json, manpage,
markup, nroff, plugin, reference, table, table of contents, tcler's wiki, text, url, wiki
CATEGORY
Documentation tools
COPYRIGHT
Copyright (c) 2009-2019 Andreas Kupries <andreas_kupries@users.sourceforge.net>