Provided by: tcllib_1.14-dfsg-1_all bug

NAME

       doctools::toc::import - Importing keyword indices

SYNOPSIS

       package require doctools::toc::import  ?0.1?

       package require Tcl  8.4

       package require doctools::config

       package require doctools::toc::structure

       package require snit

       package require pluginmgr

       ::doctools::toc::import objectName

       objectName method ?arg arg ...?

       objectName destroy

       objectName import text text ?format?

       objectName import file path ?format?

       objectName import object text object text ?format?

       objectName import object file object path ?format?

       objectName config names

       objectName config get

       objectName config set name ?value?

       objectName config unset pattern...

       objectName includes

       objectName include add path

       objectName include remove path

       objectName include clear

       IncludeFile currentfile path

       import text configuration

_________________________________________________________________

DESCRIPTION

       This  package  provides a class to manage the plugins for the import of tables of contents
       from other formats, i.e. their conversion from, for example doctoc, json, etc.

       This is one of the three public pillars the management of tables of contents  resides  on.
       The other two pillars are

       [1]    Exporting 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 output of  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_IMPORT_PLUGINS,

       [2]    the environment variable DOCTOOLS_TOC_PLUGINS,

       [3]    the environment variable DOCTOOLS_PLUGINS,

       [4]    the path "~/.doctools/toc/import/plugin"

       [5]    the path "~/.doctools/toc/plugin"

       [6]    the path "~/.doctools/plugin"

       [7]    the path "~/.doctools/toc/import/plugins"

       [8]    the path "~/.doctools/toc/plugins"

       [9]    the path "~/.doctools/plugins"

       [10]   the registry entry "HKEY_CURRENT_USER\SOFTWARE\DOCTOOLS\TOC\IMPORT\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 two predefined import plugins, namely

       doctoc See doctoc import plugin for details.

       json   See json import plugin for details.

       Readers  wishing  to  write  their own import plugin for some format, i.e.  plugin writers
       reading and understanding the section containing the Import 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::import objectName
              This command creates a new import 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::import  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 import text text ?format?
              This method takes the text and  converts  it  from  the  specified  format  to  the
              canonical  serialization  of  a  table  of contents using the import plugin for the
              format. An error is thrown if no  plugin  could  be  found  for  the  format.   The
              serialization 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 Import plugin API
              v2 reference.

       objectName import file path ?format?
              This method is a convenient wrapper around the import text method described by  the
              previous  item.  It reads the contents of the specified file into memory, feeds the
              result into import text and returns the resulting serialization as its own result.

       objectName import object text object text ?format?
              This method is a convenient wrapper around the import text method described by  the
              previous  item.   It  expects  that  object  is  an  object  command  supporting  a
              deserialize method expecting the canonical serialization of a  table  of  contents.
              It  imports  the  text using import text and then feeds the resulting serialization
              into the object via deserialize.  This  method  returns  the  empty  string  as  it
              result.

       objectName import object file object path ?format?
              This  method  behaves  like  import  object  text, except that it reads the text to
              convert from the specified file instead of being given it as argument.

       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 overriden 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.

       objectName includes
              This  method  returns  a  list  containing  the currently specified paths to use to
              search for include files when processing input.  The order of  paths  in  the  list
              corresponds  to  the  order  in  which  they are used, from first to last, and also
              corresponds to the order in which they were added to the object.

       objectName include add path
              This methods adds the specified path to the list of paths  to  use  to  search  for
              include  files  when  processing  input.  The path is added to the end of the list,
              causing it to be searched after all previously  added  paths.  The  result  of  the
              command is the empty string.

              The method does nothing if the path is already known.

       objectName include remove path
              This methods removes the specified path from the list of paths to use to search for
              include files when processing input. The result of the command is the empty string.

              The method does nothing if the path is not known.

       objectName include clear
              This method clears the list of paths to  use  to  search  for  include  files  when
              processing input. The result of the command is the empty string.

IMPORT PLUGIN API V2 REFERENCE

       Plugins  are  what this package uses to manage the support for any input 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::import::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 import methods of import 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]    The  plugin  can  expect  that  a  command  named  IncludeFile is present, with the
              signature

              IncludeFile currentfile path
                     This command has to be invoked by the plugin  when  it  has  to  process  an
                     included  file,  if the format has the concept of such. An example of such a
                     format would be doctoc.

                     The plugin has to supply the following arguments

                     string currentfile
                            The path of the file it is currently  processing.  This  may  be  the
                            empty string if no such is known.

                     string path
                            The  path  of  the include file as specified in the include directive
                            being processed.

                     The result of the command will be a 5-element list containing

                     [1]    A boolean flag indicating the success (True) or  failure  (False)  of
                            the operation.

                     [2]    In  case  of success the contents of the included file, and the empty
                            string otherwise.

                     [3]    The resolved, i.e. absolute path of the included file,  if  possible,
                            or  the  unchanged  path  argument.  This  is for display in an error
                            message,  or  as  the  currentfile  argument  of  another   call   to
                            IncludeFile should this file contain more files.

                     [4]    In case of success an empty string, and for failure a code indicating
                            the reason for it, one of

                            notfound
                                   The specified file could not be found.

                            notread
                                   The specified file was found, but not be read into memory.

                     [5]    An empty string in case of success of  a  notfound  failure,  and  an
                            additional error message describing the reason for a notread error in
                            more detail.

       [5]    A plugin has to provide one command, with the signature shown below.

              import text configuration
                     Whenever an import manager of doctools::toc has to parse input for  a  table
                     of contents it will invoke this command.

                     string text
                            This  argument  will  contain the text encoding the table of contents
                            per the format the plugin is for.

                     dictionary configuration
                            This argument will contain the current configuration to apply to  the
                            parsing, 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.

       [6]    A single usage cycle of a plugin consists of the invokations of the command import.
              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 SF Trackers
       [http://sourceforge.net/tracker/?group_id=12883].   Please  also  report  any  ideas   for
       enhancements you may have for either package and/or documentation.

KEYWORDS

       conversion,  doctoc,  documentation,  import,  json,  manpage,  markup,  parsing,  plugin,
       reference, table, table of contents, url

CATEGORY

       Documentation tools

COPYRIGHT

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