bionic (3) toc_import.3tcl.gz

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

NAME

       doctools::toc::import - Importing keyword indices

SYNOPSIS

       package require doctools::toc::import  ?0.2?

       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 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.

       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 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

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

CATEGORY

       Documentation tools

       Copyright (c) 2009-2018 Andreas Kupries <andreas_kupries@users.sourceforge.net>