| The <media> Tag
                          WebMake allows you to refer to files and web pages symbolically, separating
                          the site layout from the URL structure, and avoiding later problems with
                          dangling links when a page's URL is changed. This is done using $(url_refs).
                          
                         
                          This works well for content items defined in WebMake, such as output files
                          defined using the <out> tag. However it is not handy
                          when dealing with a images or other files that are not
                          generated using WebMake.
                          
                         
                          Therefore media files, such as images, and external, non-WebMake-controlled
                          files, can be searched for using the <media> tag. This tag allows you to
                          search a data source (directory, etc.) for a pattern.
                          
                         
                          
                            Note that data sources which do not map to files in a filesystem, or other
                             methods accessible to a web browser browsing your site, do not make sense
                             for the <media> tag; so, for example, the svfile: protocol is
                             not supported, as a web browser cannot load an image from a CSV file.
                             As a result, currently only one data source protocol can be used with
                             the <media> tag, namely file:.
                            
                           
                           
                            Attributes Supported By Datasource Tags 
                              
                                src
                              
                                
                                  All datasources require this attribute, which
                                   specifies a protocol and path, in a URL-style syntax:
                                   protocol:path . file: is the default protocol, if none is
                                   specified.
                                  
                                
                                name
                              
                                
                                  This attribute is used to specify the pattern of data,
                                   under this path, which will be converted into content or media items.
                                   The part of the data's location which matches this name pattern will
                                   become the name of the item. Typically, WebMake glob patterns, such as "*.txt" or ".../*.html" are used.
                                  
                                
                                skip
                              
                                
                                  A pattern which should match filenames that should be
                                   skipped. Files that match this pattern will not be included as content
                                   or media items, or as metatables. Glob patterns, again, are
                                   used here.
                                  
                                
                                prefix
                              
                                
                                  The items' names can be further modified by specifying
                                   a prefix and/or suffix; these strings are prepended or
                                   appended to the raw name to make the name the content is given.
                                  
                                
                                suffix
                              
                                
                                  See above.
                                  
                                
                                namesubst
                              
                                
                                  a Perl-formatted s// substitution, which is used to
                                   convert source filenames to content names. See the example under
                                   The File: Protocol, below.
                                  
                                
                                nametr
                              
                                
                                  a Perl tr// translation, which is used to convert
                                   source filenames to content names.
                                  
                                
                                listname
                              
                                
                                  a name of a content item. This content item will be
                                   created, and will contain the names of all content items picked up by
                                   the <contents> or <media> search.
                                  
                                
                                metatable
                              
                                
                                  a search pattern, similar to name above, which
                                   provides filenames from which metadata will be loaded.
                                  
                                 
                              In addition, the attributes supported by the content tag can
                              be specified as attributes to <contents>, including
                              format, up, map, etc.
                              
                             
                              Also, the attributes supported by the <metatable> tag
                              can be used if you've specified a metatable attribute.
                              
                             
                              The content blocks picked up from a <contents> search can
                              also contain meta-data, such as headlines, visibilty dates, workflow approval
                              statuses, etc. by including metadata.
                              
                             
                              
                             
                            The file: Protocol 
                              The file: protocol loads content from a directory; each file is made into one
                              content chunk. The src attribute indicates the source directory, the
                              name attribute indicates the glob pattern that will pick up the
                              content items in question.
                              
                             
                              
                                <contents src="stories" name="*.txt" />
                                
                               
                              The filename of the file will be used as the content chunk's name -- unless
                              you use the namesubst command; see below for details on this.
                              
                             
                              Note that, for efficiency, the files in question are not actually opened until
                              their content chunks are referenced using ${name} or
                              get_content("name").
                              
                             Searching Recursively Through A Directory Tree
                              Normally only the top level of files inside the src directory are added to
                              the content set. However, if the name pattern starts with .../, the
                              directory will be searched recursively:
                              
                             
                              
                                <contents src="stories" name=".../*.txt" />
                                
                               
                              The resulting content items will contain the full path from that directory
                              down, i.e. the file stories/dir1/foo/bar.txt exists, the example above
                              would define a content item called ${dir1/foo/bar.txt}.
                              
                             The namesubst Option
                              If you use the namesubst command, the filename will be modified using that
                              substitution, to give the content item's name. So, for example, this contents
                              tag:
                              
                             
                              
                                <contents src="stories" name="*.txt" namesubst="s/.txt//" />
                                
                               
                              will load these example files as follows:
                              
                             
                               
                                
                                  
                                    | Filename | Content Name |  
                                    | stories/index.txt | ${index} |  
                                    | stories/foo.txt | ${foo} |  
                                    | stories/directory/bar.txt | ${directory/bar} |  
                                    | stories/zz/gum/baz.txt | ${zz/gum/baz} |  Loading Metadata Using the Metatable Attribute
                              You can now load metadata from external files while searching a directory tree
                              for content items or media files. This allows you to load image titles, etc.
                              from files which match the filename pattern you specify in the metatable
                              attribute.
                              
                             
                              The attributes supported by the <metatable> tag can be
                              used in the datasource tag's attribute set, if you've specified a
                              metatable attribute, allowing you to define the format of the
                              metatable files you expect to find.
                              
                             
                              There's one major difference between normal metatables and metatables
                              found via a data source; the names in this kind of metatable refer to
                              the content or media object's filename, not its content name.
                              
                             
                              In other words, the names of any content items referred to in the metatable
                              files will be modified, as follows:
                              
                             
                              
                                
                                  if the name attribute contains .../, then the content items
                                   could be deep in a subdirectory. The metatable file does not have
                                   to contain the full path to the content item's name; it can just
                                   contain the item's filename relative to the metatable itself.
                                
                                  if a namesubst or nametr function is specified, the content
                                   names in the metatable will be processed with this. Again, this
                                   means that the metatable data just has to provide the filename,
                                   not whatever the resulting content item will be called.
                                  
                                 
                              These features will hopefully make the operation a little more intuitive, as
                              users who add files to a media or contents directory will not have to figure
                              out what the resulting content item will be called; they can just refer to
                              them by their filename, when tagging them with metadata.
                              
                             
                              
                             Example
                           
                          
                          
  <media src="file:images" name=".../*.gif" />
  <media src="file:images" name=".../*.jpg" />
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