Add support for Javascript expressions in v-html attributes

`v-html` attributes currently only support direct references to
top-level variables in the template data.

Use the Peast Javascript expression parsing support to make it
possible to evaluate expressions in `v-html` attributes.

Bug: T396098

Author: codders

src/Component.php

@@ -319,7 +319,7 @@ private function handleRawHtml( DOMNode $node, array $data ) {
 			$variableName = $node->getAttribute( 'v-html' );
 			$node->removeAttribute( 'v-html' );
 
-			$this->appendHTML( $node, $data[$variableName] );
+			$this->appendHTML( $node, $this->app->evaluateExpression( $variableName, $data ) );
 		}
 	}
 

tests/php/TemplatingTest.php

@@ -102,6 +102,15 @@ public function testTemplateWithVhtmlVariable_ReplacesVariableWithGivenValue() {
 		$this->assertSame( '<div><div><p>some value</p></div></div>', $result );
 	}
 
+	public function testTemplateWithVhtmlVariableNestedData_ReplacesVariableWithGivenValue() {
+		$result = $this->createAndRender(
+			'<div><div v-html="value.html"></div></div>',
+			[ 'value' => [ 'html' => '<p>some value</p>' ] ]
+		);
+
+		$this->assertSame( '<div><div><p>some value</p></div></div>', $result );
+	}
+
 	public function testTemplateWithVhtmlVariableAndAttributeBinding_ReplacesBoth(): void {
 		$result = $this->createAndRender(
 			'<div><div :data-a="a" v-html="html"></div></div>',