Add a GraphViz GV exporter.

spec/drupol/phptree/Exporter/GvSpec.php

@@ -0,0 +1,109 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace spec\drupol\phptree\Exporter;
+
+use drupol\phptree\Exporter\Gv;
+use drupol\phptree\Node\AttributeNode;
+use drupol\phptree\Node\ValueNode;
+use PhpSpec\ObjectBehavior;
+
+class GvSpec extends ObjectBehavior
+{
+    public function it_can_export_to_dot_gv()
+    {
+        $attributes = [
+            'ratio' => 'fill',
+            'node' => [
+                'style' => 'filled',
+            ],
+        ];
+
+        $this
+            ->setGraphAttributes($attributes);
+
+        $tree = new AttributeNode(['label' => 'root']);
+        $child1 = new ValueNode('child1');
+        $child2 = new ValueNode('child2');
+        $child3 = new ValueNode('child3');
+        $child4 = new ValueNode('child4');
+        $child1->add($child4);
+
+        $tree
+            ->add($child1, $child2, $child3);
+
+        $nodes['root'] = [
+            'hash' => \sha1(\spl_object_hash($tree)),
+            'value' => 'root',
+        ];
+        $nodes['child1'] = [
+            'hash' => \sha1(\spl_object_hash($child1)),
+            'value' => $child1->getValue(),
+        ];
+        $nodes['child2'] = [
+            'hash' => \sha1(\spl_object_hash($child2)),
+            'value' => $child2->getValue(),
+        ];
+        $nodes['child3'] = [
+            'hash' => \sha1(\spl_object_hash($child3)),
+            'value' => $child3->getValue(),
+        ];
+        $nodes['child4'] = [
+            'hash' => \sha1(\spl_object_hash($child4)),
+            'value' => $child4->getValue(),
+        ];
+
+        $result = <<<EOF
+digraph PHPTreeGraph {
+
+  ratio = fill
+  node [style="filled"]
+
+  "{$nodes['root']['hash']}" [label="{$nodes['root']['value']}"]
+  "{$nodes['child1']['hash']}" [label="{$nodes['child1']['value']}"]
+  "{$nodes['child4']['hash']}" [label="{$nodes['child4']['value']}"]
+  "{$nodes['child2']['hash']}" [label="{$nodes['child2']['value']}"]
+  "{$nodes['child3']['hash']}" [label="{$nodes['child3']['value']}"]
+
+  "{$nodes['root']['hash']}" -> "{$nodes['child1']['hash']}";
+  "{$nodes['child1']['hash']}" -> "{$nodes['child4']['hash']}";
+  "{$nodes['root']['hash']}" -> "{$nodes['child2']['hash']}";
+  "{$nodes['root']['hash']}" -> "{$nodes['child3']['hash']}";
+
+}
+EOF;
+        $this
+            ->export($tree)
+            ->shouldReturn($result);
+
+        $this->setDirected(false);
+
+        $result = <<<EOF
+graph PHPTreeGraph {
+
+  ratio = fill
+  node [style="filled"]
+
+  "{$nodes['root']['hash']}" [label="{$nodes['root']['value']}"]
+  "{$nodes['child1']['hash']}" [label="{$nodes['child1']['value']}"]
+  "{$nodes['child4']['hash']}" [label="{$nodes['child4']['value']}"]
+  "{$nodes['child2']['hash']}" [label="{$nodes['child2']['value']}"]
+  "{$nodes['child3']['hash']}" [label="{$nodes['child3']['value']}"]
+
+  "{$nodes['root']['hash']}" -- "{$nodes['child1']['hash']}";
+  "{$nodes['child1']['hash']}" -- "{$nodes['child4']['hash']}";
+  "{$nodes['root']['hash']}" -- "{$nodes['child2']['hash']}";
+  "{$nodes['root']['hash']}" -- "{$nodes['child3']['hash']}";
+
+}
+EOF;
+        $this
+            ->export($tree)
+            ->shouldReturn($result);
+    }
+    public function it_is_initializable()
+    {
+        $this->shouldHaveType(Gv::class);
+    }
+}

src/Exporter/Gv.php

@@ -0,0 +1,226 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace drupol\phptree\Exporter;
+
+use drupol\phptree\Node\AttributeNodeInterface;
+use drupol\phptree\Node\NodeInterface;
+use drupol\phptree\Node\ValueNodeInterface;
+
+/**
+ * Class Gv.
+ */
+class Gv implements ExporterInterface
+{
+    /**
+     * The graph attributes.
+     *
+     * @var string[]
+     */
+    private $attributes = [];
+    /**
+     * Is the graph directed or undirected.
+     *
+     * @var bool
+     */
+    private $directed = true;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function export(NodeInterface $node): string
+    {
+        $directed = true === $this->getDirected() ?
+            '->' :
+            '--';
+
+        $attributes = '';
+        foreach ($this->attributes as $key => $attribute) {
+            if (\is_string($attribute)) {
+                $attributes .= \sprintf(
+                    '  %s = %s' . "\n",
+                    $key,
+                    $attribute
+                );
+
+                continue;
+            }
+
+            if (\is_array($attribute)) {
+                $attributesText = \array_map(
+                    static function ($key, $value) {
+                        return \sprintf('%s="%s"', $key, $value);
+                    },
+                    \array_keys($attribute),
+                    $attribute
+                );
+
+                $attributes .= \sprintf(
+                    '  %s %s' . "\n",
+                    $key,
+                    '[' . \implode(' ', $attributesText) . ']'
+                );
+
+                continue;
+            }
+        }
+
+        $nodes = '';
+        foreach ($node->all() as $child) {
+            $nodes .= \sprintf(
+                '  "%s" %s' . "\n",
+                $this->getHash($child),
+                $this->getNodeAttributes($child)
+            );
+        }
+
+        $edges = '';
+        foreach ($this->findEdges($node) as $parent => $child) {
+            $edges .= \sprintf(
+                '  "%s" %s "%s";' . "\n",
+                $this->getHash($parent),
+                $directed,
+                $this->getHash($child)
+            );
+        }
+
+        return $this->getGv($attributes, $nodes, $edges);
+    }
+
+    /**
+     * Check if the graph is directed or undirected.
+     *
+     * @return bool
+     *   True if directed, false otherwise.
+     */
+    public function getDirected(): bool
+    {
+        return $this->directed;
+    }
+
+    /**
+     * Set the graph as directed.
+     *
+     * @param bool $directed
+     *   True for a directed graph, false otherwise.
+     *
+     * @return \drupol\phptree\Exporter\Gv
+     *   The exporter.
+     */
+    public function setDirected(bool $directed = true): Gv
+    {
+        $this->directed = $directed;
+
+        return $this;
+    }
+
+    /**
+     * Set the graph attributes.
+     *
+     * @param array $attributes
+     *   The graph attributes.
+     *
+     * @return \drupol\phptree\Exporter\Gv
+     *   The exporter.
+     */
+    public function setGraphAttributes(array $attributes): Gv
+    {
+        $this->attributes = $attributes;
+
+        return $this;
+    }
+
+    /**
+     * Recursively find all the edges in a tree.
+     *
+     * @param \drupol\phptree\Node\NodeInterface $node
+     *   The root node.
+     *
+     * @return \Generator
+     *   Yield the parent and child node.
+     */
+    protected function findEdges(NodeInterface $node): iterable
+    {
+        foreach ($node->children() as $child) {
+            yield $node => $child;
+
+            yield from $this->findEdges($child);
+        }
+    }
+
+    /**
+     * Get the default GV file content.
+     *
+     * @param string $attributes
+     * @param string $nodes
+     * @param string $edges
+     *   The edges.
+     *
+     * @return string
+     *   The content of the .gv file.
+     */
+    protected function getGv(string $attributes = '', string $nodes = '', string $edges = ''): string
+    {
+        $graphType = $this->getDirected() ?
+            'digraph' :
+            'graph';
+
+        return <<<EOF
+{$graphType} PHPTreeGraph {
+
+{$attributes}
+{$nodes}
+{$edges}
+}
+EOF;
+    }
+
+    /**
+     * Get the hash of a node.
+     *
+     * @param \drupol\phptree\Node\NodeInterface $node
+     *   The node.
+     *
+     * @return string
+     *   The hash of the node.
+     */
+    protected function getHash(NodeInterface $node): string
+    {
+        return \sha1(\spl_object_hash($node));
+    }
+
+    /**
+     * Get the node attributes.
+     *
+     * @param \drupol\phptree\Node\NodeInterface $node
+     *   The node interface.
+     *
+     * @return string
+     *   The attributes as a string.
+     */
+    protected function getNodeAttributes(NodeInterface $node): string
+    {
+        $attributes = [];
+
+        if ($node instanceof ValueNodeInterface) {
+            $attributes['label'] = $node->getValue();
+        }
+
+        if ($node instanceof AttributeNodeInterface) {
+            foreach ($node->getAttributes() as $key => $value) {
+                $attributes[$key] = $value;
+            }
+        }
+
+        $attributesText = \array_map(
+            static function ($key, $value) {
+                return \sprintf('%s="%s"', $key, $value);
+            },
+            \array_keys($attributes),
+            $attributes
+        );
+
+        return '[' . \implode(' ', $attributesText) . ']';
+    }
+}