


doctools::toc::export::Documentatiodoctools::toc::export::json(n)


______________________________________________________________________________

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  doc-
       tools::toc::export, the export manager.

       Using it from a regular interpreter is possible, however only with con-
       tortions, and is not recommended.  The proper way to use this function-
       ality is through the package doctools::toc::export and the export  man-
       ager 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 gener-
              ates 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 {



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doctools::toc::export::Documentatiodoctools::toc::export::json(n)


                 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"
           }
       }




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doctools::toc::export::Documentatiodoctools::toc::export::json(n)


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  struc-
              ture, 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 serial-
       ize 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  dictio-
                     nary 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.



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doctools::toc::export::Documentatiodoctools::toc::export::json(n)


                      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 refer-
                                    enced document, a label, and a longer tex-
                                    tual  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  divi-
                                           sions)  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 hierar-
                                    chy 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



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doctools::toc::export::Documentatiodoctools::toc::export::json(n)


                                           two  entries  (references and divi-
                                           sions) 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  con-
                                           tents,  see  above. This closes the
                                           recusrive definition of the  struc-
                                           ture,  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  for-
              mat  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       SF       Trackers       [http://source-
       forge.net/tracker/?group_id=12883].  Please also report any  ideas  for
       enhancements you may have for either package and/or documentation.

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

CATEGORY
       Text formatter plugin

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














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