X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FText%2FTradition%2FParser%2FGraphML.pm;h=be3640796a80b4f7e16a35c3749a8ab70f4be581;hb=94c00c71ffabc3dc155d237364e76af4385dcb96;hp=5c6244cc924cd5030ab439ca0ca0e0d945bd6b1f;hpb=3a1f25236a16c5505e0395baec4f085ccd6b2ab1;p=scpubgit%2Fstemmatology.git

diff --git a/lib/Text/Tradition/Parser/GraphML.pm b/lib/Text/Tradition/Parser/GraphML.pm
index 5c6244c..be36407 100644
--- a/lib/Text/Tradition/Parser/GraphML.pm
+++ b/lib/Text/Tradition/Parser/GraphML.pm
@@ -12,8 +12,10 @@ Text::Tradition::Parser::GraphML
 =head1 DESCRIPTION
 
 Parser module for Text::Tradition, given a GraphML file that describes
-a collation graph.  For further information on the GraphML format for
-text collation, see http://gregor.middell.net/collatex/
+a collation graph.  Returns the information about the graph that has
+been parsed out from the GraphML.  This module is meant to be used
+with a module (e.g. CollateX or Self) that interprets the specific
+GraphML conventions of the source program.
 
 =head1 METHODS
 
@@ -21,20 +23,24 @@ text collation, see http://gregor.middell.net/collatex/
 
 =item B<parse>
 
-parse( $graph, $graphml_string );
+parse( $graphml_string );
 
-Takes an initialized Text::Tradition::Graph object and a string
-containing the GraphML; creates the appropriate nodes and edges on the
-graph.
+Takes a string containing the GraphML; returns a list of nodes, edges,
+and their associated data.
 
 =cut
 
-use vars qw/ $xpc %nodedata /;
+use vars qw/ $xpc $nodedata $witnesses /;
+
+# Return graph -> nodeid -> { key1/val1, key2/val2, key3/val3 ... }
+#              -> edgeid -> { source, target, wit1/val1, wit2/val2 ...}
 
 sub parse {
-    my( $tradition, $graphml_str ) = @_;
+    my( $graphml_str ) = @_;
+
+    my $graph_hash = { 'nodes' => [],
+                       'edges' => [] };
 
-    my $collation = $tradition->collation;
     my $parser = XML::LibXML->new();
     my $doc = $parser->parse_string( $graphml_str );
     my $graphml = $doc->documentElement();
@@ -42,126 +48,74 @@ sub parse {
     $xpc->registerNs( 'g', 'http://graphml.graphdrawing.org/xmlns' );
     
     # First get the ID keys, for witnesses and for collation data
-    my %witnesses;
     foreach my $k ( $xpc->findnodes( '//g:key' ) ) {
-	# Each key has a 'for' attribute; the edge keys are witnesses, and
-	# the node keys contain an ID and string for each node.
-
-	if( $k->getAttribute( 'for' ) eq 'node' ) {
-	    # The node data keys we expect are:
-	    # 'number' -> unique node identifier
-	    # 'token' -> reading for the node
-	    # 'identical' -> the node of which this node is 
-	    #                a transposed version
-	    # 'position' -> a calculated position for the node
-	    $nodedata{ $k->getAttribute( 'attr.name' ) } = $k->getAttribute( 'id' );
-	} else {
-	    $witnesses{ $k->getAttribute( 'id' ) } = $k->getAttribute( 'attr.name' );
-	}
-    }
-
-    my $has_explicit_positions = defined $nodedata{'position'};
-
-    # Add the witnesses that we have found
-    foreach my $wit ( values %witnesses ) {
-	$tradition->add_witness( 'sigil' => $wit );
+        # Each key has a 'for' attribute; the edge keys are witnesses, and
+        # the node keys contain an ID and string for each node.
+        my $keyid = $k->getAttribute( 'id' );
+        my $keyname = $k->getAttribute( 'attr.name' );
+
+        if( $k->getAttribute( 'for' ) eq 'node' ) {
+            # Keep track of the XML identifiers for the data carried
+            # in each node element.
+            $nodedata->{$keyid} = $keyname
+        } else {
+            $witnesses->{$keyid} = $keyname;
+        }
     }
 
     my $graph_el = $xpc->find( '/g:graphml/g:graph' )->[0];
 
-    # Add the nodes to the graph.  First delete the start node, because
-    # GraphML graphs will have their own start nodes.
-    $collation->del_reading( $collation->start() );
-    # Map from XML IDs to node name/identity
-    my %node_name;
-    # Keep track of whatever extra info we're passed
-    my $extra_data = {};
+    my $node_reg = {};
+
+    # Add the nodes to the graph hash.
+    print STDERR "Reading graphml nodes\n"; 
     my @nodes = $xpc->findnodes( '//g:node' );
     foreach my $n ( @nodes ) {
-	my $id = _lookup_node_data( $n, 'number' );
-	my $label = _lookup_node_data( $n, 'token' );
-	my $gnode = $collation->add_reading( $id );
-	$node_name{ $n->getAttribute('id') } = $id;
-	$gnode->set_attribute( 'label', $label );
-
-	# Now get the rest of the data, i.e. not the ID or label
-	my $extra = {};
-	foreach my $k ( keys %nodedata ) {
-	    next if $k =~ /^(number|token)$/;
-	    $extra->{ $k } = _lookup_node_data( $n, $k );
-	}
-	$extra_data->{ $id } = $extra;
+        # Could use a better way of registering these
+        my $node_hash = {};
+        foreach my $dkey ( keys %$nodedata ) {
+            my $keyname = $nodedata->{$dkey};
+            my $keyvalue = _lookup_node_data( $n, $dkey );
+            $node_hash->{$keyname} = $keyvalue if defined $keyvalue;
+        }
+        $node_reg->{$n->getAttribute( 'id' )} = $node_hash;
+        push( @{$graph_hash->{'nodes'}}, $node_hash );
     }
-	
-    # Now add the edges.
+        
+    # Now add the edges, and cross-ref with the node objects.
+    print STDERR "Reading graphml edges\n";
     my @edges = $xpc->findnodes( '//g:edge' );
     foreach my $e ( @edges ) {
-	my $from = $node_name{ $e->getAttribute('source') };
-	my $to = $node_name{ $e->getAttribute('target') };
-	# Label according to the witnesses present.
-	my @wit_ids = $xpc->findnodes( './g:data/attribute::key', $e );
-	my @wit_names = map { $witnesses{ $_->getValue() } } @wit_ids;
-	my $label = $collation->path_label( @wit_names );
-	$collation->add_path( $from, $to, $label );
-    }
-
-    ## Reverse the node_name hash so that we have two-way lookup.
-    my %node_id = reverse %node_name;
-
-    ## Record the nodes that are marked as transposed.
-    my $tr_xpath = '//g:node[g:data[@key="' . $nodedata{'identical'} . '"]]';
-    my $transposition_nodes = $xpc->find( $tr_xpath );
-    foreach my $tn ( @$transposition_nodes ) {
-	my $id_xpath = sprintf( './g:data[@key="%s"]/text()', 
-				$nodedata{'identical'} );
-	$collation->reading( $node_id{ $tn->getAttribute( 'id' ) } )->
-	    set_identical( $collation->reading( 
-			       $node_name{ $xpc->findvalue( $id_xpath, $tn ) } ) );
-    }
-
-    # Find the beginning and end nodes of the graph.  The beginning node
-    # has no incoming edges; the end node has no outgoing edges.
-    my( $begin_node, $end_node );
-    foreach my $gnode ( $collation->readings() ) {
-	# print STDERR "Checking node " . $gnode->name . "\n";
-	my @outgoing = $gnode->outgoing();
-	my @incoming = $gnode->incoming();
-
-	unless( scalar @incoming ) {
-	    warn "Already have a beginning node" if $begin_node;
-	    $begin_node = $gnode;
-	    $collation->start( $gnode );
-	}
-	unless( scalar @outgoing ) {
-	    warn "Already have an ending node" if $end_node;
-	    $end_node = $gnode;
-	}
-    }
-
-    my @common_nodes = $collation->walk_witness_paths( $end_node );
-    # Now we have added the witnesses and their paths, so have also
-    # implicitly marked the common nodes. Now we can calculate their
-    # explicit permissions.  This is separate because it won't always
-    # be necessary with the GraphML parsing.
-    if( $has_explicit_positions ) {
-	# Record the positions that came with each graph node.
-	# TODO we really need to translate these into our own style of
-	# position identifier.  That's why we defer this until now.
-	foreach my $node_id ( keys %$extra_data ) {
-	    my $pos = $extra_data->{$node_id}->{'position'};
-	    $collation->reading( $node_name{$node_id} )->position( $pos );
-	}
-    } else {
-	# Calculate a position for each graph node.
-	$collation->calculate_positions( @common_nodes );
+        my $from = $e->getAttribute('source');
+        my $to = $e->getAttribute('target');
+
+        # We don't know whether the edge data is one per witness
+        # or one per witness type, or something else.  So we just
+        # save it and let our calling parser decide.
+        my $edge_hash = {
+            'source' => $node_reg->{$from},
+            'target' => $node_reg->{$to},
+        };
+        foreach my $wkey( keys %$witnesses ) {
+            my $wname = $witnesses->{$wkey};
+            my $wlabel = _lookup_node_data( $e, $wkey );
+            $edge_hash->{$wname} = $wlabel if $wlabel;
+        }
+        push( @{$graph_hash->{'edges'}}, $edge_hash );
     }
+    return $graph_hash;
 }
 
 sub _lookup_node_data {
     my( $xmlnode, $key ) = @_;
     my $lookup_xpath = './g:data[@key="%s"]/child::text()';
-    my $data = $xpc->findvalue( sprintf( $lookup_xpath, $nodedata{$key} ), 
-				$xmlnode );
+    my $data = $xpc->find( sprintf( $lookup_xpath, $key ), $xmlnode );
+    # If we get back an empty nodelist, we return undef.
+    if( ref( $data ) ) {
+    	return undef unless $data->size;
+    	return $data->to_literal->value;
+    }
+    # Otherwise we got back a value. Return it.
     return $data;
 }