1Graph::Easy::Edge(3) User Contributed Perl Documentation Graph::Easy::Edge(3)
2
6 Graph::Easy::Edge - An edge (a path connecting one ore more nodes)
7
9 use Graph::Easy;
10 my $ssl = Graph::Easy::Edge->new(
12 label => 'encrypted connection',
13 style => 'solid',
14 );
15 $ssl->set_attribute('color', 'red');
16 my $src = Graph::Easy::Node->new('source');
18 my $dst = Graph::Easy::Node->new('destination');
20 $graph = Graph::Easy->new();
22 $graph->add_edge($src, $dst, $ssl);
24 print $graph->as_ascii();
26
28 A "Graph::Easy::Edge" represents an edge between two (or more) nodes in
29 a simple graph.
30 Each edge has a direction (from source to destination, or back and
32 forth), plus a style (line width and style), colors etc. It can also
33 have a label, e.g. a text associated with it.
34 During the layout phase, each edge also contains a list of path-
36 elements (also called cells), which make up the path from source to
37 destination.
38
40 error()
41 $last_error = $edge->error();
42 $cvt->error($error); # set new messages
44 $cvt->error(''); # clear error
45 Returns the last error message, or '' for no error.
47 as_ascii()
49 my $ascii = $edge->as_ascii();
50 Returns the edge as a little ascii representation.
52 as_txt()
54 my $txt = $edge->as_txt();
55 Returns the edge as a little Graph::Easy textual representation.
57 label()
59 my $label = $edge->label();
60 Returns the label (also known as 'name') of the edge.
62 name()
64 my $label = $edge->name();
65 To make the interface more consistent, the "name()" method of an edge
67 can also be called, and it will returned either the edge label, or the
68 empty string if the edge doesn't have a label.
69 style()
71 my $style = $edge->style();
72 Returns the style of the edge, like 'solid', 'dotted', 'double', etc.
74 nodes()
76 my @nodes = $edge->nodes();
77 Returns the source and target node that this edges connects as objects.
79 bidirectional()
81 $edge->bidirectional(1);
82 if ($edge->bidirectional())
83 {
84 }
85 Returns true if the edge is bidirectional, aka has arrow heads on both
87 ends. An optional parameter will set the bidirectional status of the
88 edge.
89 undirected()
91 $edge->undirected(1);
92 if ($edge->undirected())
93 {
94 }
95 Returns true if the edge is undirected, aka has now arrow at all. An
97 optional parameter will set the undirected status of the edge.
98 has_ports()
100 if ($edge->has_ports())
101 {
102 ...
103 }
104 Return true if the edge has restriction on the starting or ending port,
106 e.g. either the "start" or "end" attribute is set on this edge.
107 start_port()
109 my $port = $edge->start_port();
110 Return undef if the edge does not have a fixed start port, otherwise
112 returns the port as "side, number", for example "south, 0".
113 end_port()
115 my $port = $edge->end_port();
116 Return undef if the edge does not have a fixed end port, otherwise
118 returns the port as "side, number", for example "south, 0".
119 from()
121 my $from = $edge->from();
122 Returns the node that this edge starts at. See also "to()".
124 to()
126 my $to = $edge->to();
127 Returns the node that this edge leads to. See also "from()".
129 start_at()
131 $edge->start_at($other);
132 my $other = $edge->start_at('some node');
133 Set the edge's start point to the given node. If given a node name,
135 will add that node to the graph first.
136 Returns the new edge start point node.
138 end_at()
140 $edge->end_at($other);
141 my $other = $edge->end_at('some other node');
142 Set the edge's end point to the given node. If given a node name, will
144 add that node to the graph first.
145 Returns the new edge end point node.
147 flip()
149 $edge->flip();
150 Swaps the "start" and "end" nodes on this edge, e.g. reverses the
152 direction of the edge.
153 flow()
155 my $flow = $edge->flow();
156 Returns the flow for this edge, honoring inheritance. An edge without a
158 specific flow set will inherit the flow from the node it comes from.
159 edge_flow()
161 my $flow = $edge->edge_flow();
162 Returns the flow for this edge, or undef if it has none set on either
164 the object itself or its class.
165 port()
167 my ($side, $number) = $edge->port('start');
168 my ($side, $number) = $edge->port('end');
169 Return the side and port number where this edge starts or ends.
171 Returns undef for $side if the edge has no port restriction. The
173 returned side will be one absolute direction of "east", "west", "north"
174 or "south", depending on the port restriction and flow at that edge.
175 get_attributes()
177 my $att = $object->get_attributes();
178 Return all effective attributes on this object (graph/node/group/edge)
180 as an anonymous hash ref. This respects inheritance and default values.
181 See also raw_attributes().
183 raw_attributes()
185 my $att = $object->get_attributes();
186 Return all set attributes on this object (graph/node/group/edge) as an
188 anonymous hash ref. This respects inheritance, but does not include
189 default values for unset attributes.
190 See also get_attributes().
192 attribute related methods
194 You can call all the various attribute related methods like
195 "set_attribute()", "get_attribute()", etc. on an edge, too. For
196 example:
197 $edge->set_attribute('label', 'by train');
199 my $attr = $edge->get_attributes();
200 my $raw_attr = $edge->raw_attributes();
201 You can find more documentation in Graph::Easy.
203
205 None by default.
206
208 Graph::Easy.
209
211 Copyright (C) 2004 - 2008 by Tels <http://bloodgate.com>.
212 See the LICENSE file for more details.
214perl v5.34.0 2021-07-22 Graph::Easy::Edge(3)