NAME¶
doctools::idx::export::json - JSON export plugin
SYNOPSIS¶
package require
Tcl 8.4
package require
doctools::idx::export::json ?0.1?
package require
textutil::adjust
export serial configuration
DESCRIPTION¶
This package implements the doctools keyword index export plugin for the
generation of JSON markup.
This is an internal package of doctools, for use by the higher level management
packages handling keyword indices, especially
doctools::idx::export,
the export manager.
Using it from a regular interpreter is possible, however only with contortions,
and is not recommended. The proper way to use this functionality is through
the package
doctools::idx::export and the export manager objects it
provides.
API¶
The API provided by this package satisfies the specification of the docidx
export plugin API version 2.
- export serial configuration
- This command takes the canonical serialization of a keyword index, as
specified in section Keyword index serialization format, and
contained in serial, the configuration, a dictionary, and
generates JSON markup encoding the index. The created string is then
returned as the result of the command.
JSON NOTATION OF KEYWORD INDICES¶
The JSON format used for keyword indices is a direct translation of the
Keyword index serialization format, mapping Tcl dictionaries as JSON
objects and Tcl lists as JSON arrays. For example, the Tcl serialization
doctools::idx {
label {Keyword Index}
keywords {
changelog {changelog.man cvs.man}
conversion {doctools.man docidx.man doctoc.man apps/dtplite.man mpexpand.man}
cvs cvs.man
}
references {
apps/dtplite.man {manpage dtplite}
changelog.man {manpage doctools::changelog}
cvs.man {manpage doctools::cvs}
docidx.man {manpage doctools::idx}
doctoc.man {manpage doctools::toc}
doctools.man {manpage doctools}
mpexpand.man {manpage mpexpand}
}
title {}
}
is equivalent to the JSON string
{
"doctools::idx" : {
"label" : "Keyword Index",
"keywords" : {
"changelog" : ["changelog.man","cvs.man"],
"conversion" : ["doctools.man","docidx.man","doctoc.man","apps\/dtplite.man","mpexpand.man"],
"cvs" : ["cvs.man"],
},
"references" : {
"apps\/dtplite.man" : ["manpage","dtplite"],
"changelog.man" : ["manpage","doctools::changelog"],
"cvs.man" : ["manpage","doctools::cvs"],
"docidx.man" : ["manpage","doctools::idx"],
"doctoc.man" : ["manpage","doctools::toc"],
"doctools.man" : ["manpage","doctools"],
"mpexpand.man" : ["manpage","mpexpand"]
},
"title" : ""
}
}
CONFIGURATION¶
The JSON export plugin recognizes the following configuration variables and
changes its behaviour as they specify.
- boolean indented
- If this flag is set the plugin will break the generated JSON code across
lines and indent it according to its inner structure, with each key of a
dictionary on a separate line.
If this flag is not set (the default), the whole JSON object will be written
on a single line, with minimum spacing between all elements.
- boolean aligned
- If this flag is set the generator ensures that the values for the keys in
a dictionary are vertically aligned with each other, for a nice table
effect. To make this work this also implies that indented is set.
If this flag is not set (the default), the output is formatted as per the
value of indented, without trying to align the values for
dictionary keys.
Note that this plugin ignores the standard configuration variables
user,
format,
file, and
map and their values.
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,
refering to one of the documents the index was made for.
- url
- The identifier of the reference is interpreted as an url, refering 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.
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.
KEYWORDS¶
JSON, doctools, export, index, serialization
CATEGORY¶
Text formatter plugin
COPYRIGHT¶
Copyright (c) 2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>