doctools::idx::export - Exporting keyword indices
package require doctools::idx::export ?0.2.1?
package require Tcl 8.4
package require struct::map
package require doctools::idx::structure
package require snit
package require pluginmgr
::doctools::idx::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
This package provides a class to manage the plugins for the export
of keyword indices to other formats, i.e. their conversion to, for example
docidx, HTML, etc.
This is one of the three public pillars the management of keyword
indices resides on. The other two pillars are
- [1]
- Importing keyword indices, and
- [2]
- Holding keyword indices
For information about the Concepts of keyword indices, 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 Keyword index 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_IDX_EXPORT_PLUGINS,
- [2]
- the environment variable DOCTOOLS_IDX_PLUGINS,
- [3]
- the environment variable DOCTOOLS_PLUGINS,
- [4]
- the path "~/.doctools/idx/export/plugin"
- [5]
- the path "~/.doctools/idx/plugin"
- [6]
- the path "~/.doctools/plugin"
- [7]
- the path "~/.doctools/idx/export/plugins"
- [8]
- the path "~/.doctools/idx/plugins"
- [9]
- the path "~/.doctools/plugins"
- [10]
- the registry entry
"HKEY_CURRENT_USER\SOFTWARE\DOCTOOLS\IDX\EXPORT\PLUGINS"
- [11]
- the registry entry
"HKEY_CURRENT_USER\SOFTWARE\DOCTOOLS\IDX\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
- docidx
- See docidx 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.
- [1]
- A keyword index consists of a (possibly empty) set of
keywords.
- [2]
- Each keyword in the set is identified by its name.
- [3]
- Each keyword has a (possibly empty) set of references.
- [4]
- A reference can be associated with more than one keyword.
- [5]
- A reference not associated with at least one keyword is not possible
however.
- [6]
- Each reference is identified by its target, specified as either an url or
symbolic filename, depending on the type of reference (url, or
manpage).
- [7]
- The type of a reference (url, or manpage) depends only on the reference
itself, and not the keywords it is associated with.
- [8]
- In addition to a type each reference has a descriptive label as well. This
label depends only on the reference itself, and not the keywords it is
associated with.
A few notes
- [1]
- Manpage references are intended to be used for references to the documents
the index is made for. Their target is a symbolic file name identifying
the document, and export plugins may replace symbolic with actual file
names, if specified.
- [2]
- Url references are intended on the othre hand are inteded to be used for
links to anything else, like websites. Their target is an url.
- [3]
- While url and manpage references share a namespace for their identifiers,
this should be no problem, given that manpage identifiers are symbolic
filenames and as such they should never look like urls, the identifiers
for url references.
- ::doctools::idx::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.
All objects created by the ::doctools::idx::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.
- objectName
destroy
- This method destroys the object it is invoked for.
- objectName
export serial serial ?format?
- This method takes the canonical serialization of a keyword index 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
docidx.
The specification of what a canonical serialization is
can be found in the section Keyword index 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 keyword index. 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.
Plugins are what this package uses to manage the support for any
output format beyond the Keyword index 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::idx::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 keyword index in that format.
- [3]
- The plugin can expect that the package
doctools::idx::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::idx has to generate output
for an index it will invoke this command.
- string
serial
- This argument will contain the canonical serialization of the index
for which to generate the output. The specification of what a
canonical serialization is can be found in the section Keyword
index 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 index 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 index object is expected to
contain a dictionary mapping from symbolic file names used in the
references of type manpage to actual paths (or urls). A plugin has
to be able to handle the possibility that a symbolic name 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.
Here we specify the format used by the doctools v2 packages to
serialize keyword indices as immutable values for transport, comparison,
etc.
We distinguish between regular and canonical
serializations. While a keyword index may have more than one regular
serialization only exactly one of them will be canonical.
- regular
serialization
- [1]
- An index serialization is a nested Tcl dictionary.
- [2]
- This dictionary holds a single key, doctools::idx, and its value.
This value holds the contents of the index.
- [3]
- The contents of the index are a Tcl dictionary holding the title of the
index, a label, and the keywords and references. The relevant keys and
their values are
- title
- The value is a string containing the title of the index.
- label
- The value is a string containing a label for the index.
- keywords
- The value is a Tcl dictionary, using the keywords known to the index as
keys. The associated values are lists containing the identifiers of the
references associated with that particular keyword.
Any reference identifier used in these lists has to exist as a
key in the references dictionary, see the next item for its
definition.
- references
- The value is a Tcl dictionary, using the identifiers for the references
known to the index as keys. The associated values are 2-element lists
containing the type and label of the reference, in this order.
Any key here has to be associated with at least one keyword,
i.e. occur in at least one of the reference lists which are the values
in the keywords dictionary, see previous item for its
definition.
- [4]
- The type of a reference can be one of two values,
- manpage
- The identifier of the reference is interpreted as symbolic file name,
referring to one of the documents the index was made for.
- url
- The identifier of the reference is interpreted as an url, referring to
some external location, like a website, etc.
- canonical
serialization
- The canonical serialization of a keyword index 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 the
keyword index.
- [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.
- [2]
- The references listed for each keyword of the index, if any, are listed in
ascending dictionary order of their labels, as generated by Tcl's
builtin command lsort -increasing -dict.
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.
HTML, conversion, docidx, documentation, export, formatting,
generation, index, json, keyword index, manpage, markup, nroff, plugin,
reference, tcler's wiki, text, url, wiki
Copyright (c) 2009-2019 Andreas Kupries <andreas_kupries@users.sourceforge.net>