Implement the Text exporter.

Author: drupol

spec/drupol/phptree/Exporter/TextSpec.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace spec\drupol\phptree\Exporter;
+
+use drupol\phptree\Exporter\Text;
+use drupol\phptree\Node\ValueNode;
+use PhpSpec\ObjectBehavior;
+
+class TextSpec extends ObjectBehavior
+{
+    public function it_is_initializable()
+    {
+        $this->shouldHaveType(Text::class);
+    }
+
+    public function it_can_export_to_text()
+    {
+        $tree = new ValueNode('root', 2);
+
+        $this
+            ->export($tree)
+            ->shouldReturn('[root]');
+
+        $nodes = [];
+        foreach (\range('A', 'J') as $value) {
+            $nodes[$value] = new ValueNode($value);
+        }
+
+        $tree->add(...\array_values($nodes));
+        
+        $this
+            ->export($tree)
+            ->shouldReturn('[root [A [C [G] [H]] [D [I] [J]]] [B [E] [F]]]');
+    }
+}

src/Exporter/Text.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace drupol\phptree\Exporter;
+
+use drupol\phptree\Node\ValueNodeInterface;
+
+/**
+ * Class Text
+ */
+class Text implements ExporterInterface
+{
+    /**
+     * Export the node in a string.
+     *
+     * @param \drupol\phptree\Node\ValueNodeInterface $node
+     *   The node.
+     *
+     * @return string
+     *   The string.
+     */
+    public function export(ValueNodeInterface $node): string
+    {
+        $children = [];
+        /** @var ValueNodeInterface $child */
+        foreach ($node->children() as $child) {
+            $children[] = $this->export($child);
+        }
+
+        return [] === $children ?
+            \sprintf('[%s]', $node->getValue()):
+            \sprintf('[%s %s]', $node->getValue(), \implode(' ', $children));
+    }
+}