Provided by: tcllib_1.19-dfsg-2_all bug

NAME

       doctools::toc::export::json - JSON export plugin

SYNOPSIS

       package require Tcl  8.4

       package require doctools::toc::export::json  ?0.1?

       package require textutil::adjust

       export serial configuration

_________________________________________________________________________________________________

DESCRIPTION

       This package implements the doctools table of contents export plugin for the generation of
       JSON markup.

       This is an internal package of doctools, for use by the higher level  management  packages
       handling tables of contents, especially doctools::toc::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::toc::export and the export manager objects it provides.

API

       The  API  provided by this package satisfies the specification of the doctoc export plugin
       API version 2.

       export serial configuration
              This command takes the canonical serialization of a table of contents, as specified
              in  section ToC serialization format, and contained in serial, the configuration, a
              dictionary, and generates JSON markup encoding the table.  The  created  string  is
              then returned as the result of the command.

JSON NOTATION OF TABLES OF CONTENTS

       The  JSON  format  used  for  tables  of  contents  is  a  direct  translation  of the ToC
       serialization format, mapping Tcl dictionaries as JSON  objects  and  Tcl  lists  as  JSON
       arrays.  For example, the Tcl serialization

              doctools::toc {
                  items {
                      {reference {
                    desc {DocTools - Tables of Contents}
                     id introduction.man
                     label doctools::toc::introduction
                }}
                {division {
                     id processing.man
                     items {
                         {reference {
                        desc {doctoc serialization utilities}
                        id structure.man
                        label doctools::toc::structure
                    }}
                    {reference {
                        desc {Parsing text in doctoc format}
                        id parse.man
                        label doctools::toc::parse
                    }}
                     }
                           label Processing
                      }}
                  }
                  label {Table of Contents}
                  title TOC
              }

       is equivalent to the JSON string

              {
                  "doctools::toc" : {
                      "items" : [{
                          "reference" : {
                              "desc"  : "DocTools - Tables of Contents",
                              "id"    : "introduction.man",
                              "label" : "doctools::toc::introduction"
                          }
                      },{
                          "division" : {
                              "id"    : "processing.man",
                              "items" : [{
                                  "reference" : {
                                      "desc"  : "doctoc serialization utilities",
                                      "id"    : "structure.man",
                                      "label" : "doctools::toc::structure"
                                  }
                              },{
                                  "reference" : {
                                      "desc"  : "Parsing text in doctoc format",
                                      "id"    : "parse.man",
                                      "label" : "doctools::toc::parse"
                                  }
                              }],
                              "label" : "Processing"
                          }
                      }],
                      "label" : "Table of Contents",
                      "title" : "TOC"
                  }
              }

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.

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

       JSON, doctools, export, serialization, table of contents, toc

CATEGORY

       Text formatter plugin

COPYRIGHT

       Copyright (c) 2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>