Merge pull request #28 from clue-labs/omit-name

Omit root graph name unless explicitly assigned via graphviz.name attribute
graphp · Oct 9, 2018 · 80e5b26 · 80e5b26
2 parents 1a9b92a + 4d14455
commit 80e5b26
Show file tree

Hide file tree

Showing 3 changed files with 63 additions and 12 deletions.
diff --git a/README.md b/README.md
@@ -99,6 +99,19 @@ $hello->createEdgeTo($world);
 
 See also the [examples](examples/).
 
+Additionally, this library accepts an optional `graphviz.name` attribute that
+will be used as the name (or ID) for the root graph object in the DOT output if
+given. Unless explicitly assigned, this will be omitted by default. It is common
+to assign a `G` here, but usually there should be no need to assign this. Among
+others, this may be used as the title or tooltip in SVG output.
+
+```php
+$graph = new Fhaculty\Graph\Graph();
+$graph->setAttribute('graphviz.name', 'G');
+
+$graph->createVertex('first');
+```
+
 ### Vertex attributes
 
 GraphViz supports a number of attributes on each vertex instance (GraphViz calls

diff --git a/src/GraphViz.php b/src/GraphViz.php
@@ -228,7 +228,17 @@ public function createScript(Graph $graph)
         $alg = new Directed($graph);
         $directed = $alg->hasDirected();
 
-        $script = ($directed ? 'di':'') . 'graph G {' . self::EOL;
+        /*
+         * The website [http://www.graphviz.org/content/dot-language] uses the term `ID` when displaying
+         * the abstract grammar for the DOT language.
+         * But the man pages for dot use the term `name` when describing the graph file language.
+         */
+        $name = $graph->getAttribute('graphviz.name');
+        if ($name !== null) {
+            $name = $this->escapeId($name) . ' ';
+        }
+
+        $script = ($directed ? 'di':'') . 'graph ' . $name . '{' . self::EOL;
 
         // add global attributes
         $globals = array(

diff --git a/tests/GraphVizTest.php b/tests/GraphVizTest.php
@@ -18,7 +18,35 @@ public function testGraphEmpty()
         $graph = new Graph();
 
         $expected = <<<VIZ
-graph G {
+graph {
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->graphViz->createScript($graph));
+    }
+
+    public function testGraphWithName()
+    {
+        $graph = new Graph();
+        $graph->setAttribute('graphviz.name', 'G');
+
+                $expected = <<<VIZ
+graph "G" {
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->graphViz->createScript($graph));
+    }
+
+    public function testGraphWithNameWithSpaces()
+    {
+        $graph = new Graph();
+        $graph->setAttribute('graphviz.name', 'My Graph Name');
+
+                $expected = <<<VIZ
+graph "My Graph Name" {
 }
 
 VIZ;
@@ -33,7 +61,7 @@ public function testGraphIsolatedVertices()
         $graph->createVertex('b');
 
         $expected = <<<VIZ
-graph G {
+graph {
   "a"
   "b"
 }
@@ -51,7 +79,7 @@ public function testGraphDefaultAttributes()
         $graph->setAttribute('graphviz.edge.color', 'grey');
 
         $expected = <<<VIZ
-graph G {
+graph {
   graph [bgcolor="transparent"]
   node [color="blue"]
   edge [color="grey"]
@@ -69,7 +97,7 @@ public function testUnknownGraphAttributesWillBeDiscarded()
         $graph->setAttribute('graphviz.unknown.color', 'red');
 
         $expected = <<<VIZ
-graph G {
+graph {
 }
 
 VIZ;
@@ -88,7 +116,7 @@ public function testEscaping()
 
 
         $expected = <<<VIZ
-graph G {
+graph {
   "a"
   "b¹²³ is; ok\\\\ay, &quot;right&quot;?"
   3
@@ -107,7 +135,7 @@ public function testGraphDirected()
         $graph->createVertex('a')->createEdgeTo($graph->createVertex('b'));
 
         $expected = <<<VIZ
-digraph G {
+digraph {
   "a" -> "b"
 }
 
@@ -124,7 +152,7 @@ public function testGraphMixed()
         $graph->createVertex('c')->createEdge($graph->getVertex('b'));
 
         $expected = <<<VIZ
-digraph G {
+digraph {
   "a" -> "b"
   "c" -> "b" [dir="none"]
 }
@@ -144,7 +172,7 @@ public function testGraphUndirectedWithIsolatedVerticesFirst()
         $graph->getVertex('b')->createEdge($graph->getVertex('c'));
 
         $expected = <<<VIZ
-graph G {
+graph {
   "d"
   "a" -- "b"
   "b" -- "c"
@@ -165,7 +193,7 @@ public function testVertexLabels()
         $graph->createVertex('e')->setBalance(2)->setAttribute('graphviz.label', 'unnamed');
 
         $expected = <<<VIZ
-graph G {
+graph {
   "a" [label="a (+1)"]
   "b" [label="b (0)"]
   "c" [label="c (-1)"]
@@ -188,7 +216,7 @@ public function testEdgeLayoutAtributes()
         $graph->createVertex('5a')->createEdge($graph->createVertex('5b'))->getAttributeBag()->setAttributes(array('graphviz.a' => 'b', 'graphviz.c' => 'd'));
 
         $expected = <<<VIZ
-graph G {
+graph {
   "1a" -- "1b"
   "2a" -- "2b" [numeric=20]
   "3a" -- "3b" [textual="forty"]
@@ -213,7 +241,7 @@ public function testEdgeLabels()
         $graph->createVertex('7a')->createEdge($graph->createVertex('7b'))->setFlow(70)->setAttribute('graphviz.label', 'prefixed');
 
         $expected = <<<VIZ
-graph G {
+graph {
   "1a" -- "1b"
   "2a" -- "2b" [label=20]
   "3a" -- "3b" [label="0/30"]