Merge pull request #15 from vanilla/feature/has-children-function

Add the hasChildren() function

README.md

@@ -85,6 +85,7 @@ Functions are called using the `functionName()` syntax. Ebi provides a set of de
 | floor           | Round fractions down. | [floor](https://secure.php.net/manual/en/function.floor.php)
 | formatDate      | Format a date. | [date_format](https://secure.php.net/manual/en/function.date-format.php)
 | formatNumber    | Format a number with grouped thousands. | [number_format](https://secure.php.net/manual/en/function.number-format.php)
+| hasChildren     | Checks if the component has children passed to it. Pass the name of a block to test for that specific child.
 | htmlEncode      | Convert special characters to HTML entities. | [htmlspecialchars](https://secure.php.net/manual/en/function.htmlspecialchars.php)
 | join            | Join the elements of an array into a string. | [implode](https://secure.php.net/manual/en/function.implode.php)
 | lcase           | Lowercase a string. | [strtolower](https://secure.php.net/manual/en/function.strtolower.php), [mb_strtolower](https://secure.php.net/manual/en/function.mb-strtolower.php)

src/Compiler.php

@@ -230,6 +230,14 @@ class Compiler {
     public function __construct() {
         $this->expressions = new ExpressionLanguage();
         $this->expressions->setNamePattern('/[@a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/A');
+        $this->expressions->register(
+            'hasChildren',
+            function ($name = null) {
+                return empty($name) ? 'isset($children[0])' : "isset(\$children[$name ?: 0])";
+            },
+            function ($name = null) {
+                return false;
+            });
     }
 
     /**

tests/TemplateTest.php

@@ -42,6 +42,14 @@ public function testWithAsBreadcrumbsExample() {
         $this->assertEquals('3', $r);
     }
 
+    /**
+     * Test the hasChildren function.
+     */
+    public function testHasChildren() {
+        $r = $this->renderFixture('has-children');
+        $this->assertEquals('<div>child!</div>', trim($r));
+    }
+
     /**
      *
      */

tests/fixtures/has-children.html

@@ -0,0 +1,3 @@
+<x x-component="child-test"><div x-if="hasChildren()" x-children></div></x>
+<child-test>child!</child-test>
+<child-test />