Add support for v-else-if attributes

php-vuejs-templating already supports `v-if` and `v-else` attributes.
Add support for `v-else-if` to complete the conditional node support.

Bug: T398318

Author: codders

src/Component.php

@@ -188,6 +188,7 @@ private function handleIf( DOMNodeList $nodes, array $data ) {
 		// Iteration of iterator breaks if we try to remove items while iterating, so defer node
 		// removing until finished iterating.
 		$nodesToRemove = [];
+		$previousIfCondition = false;
 		foreach ( $nodes as $node ) {
 			if ( $this->isTextNode( $node ) ) {
 				continue;
@@ -203,7 +204,17 @@ private function handleIf( DOMNodeList $nodes, array $data ) {
 					$nodesToRemove[] = $node;
 				}
 
-				$previousIfCondition = $condition;
+				$previousIfCondition = $previousIfCondition || $condition;
+			} elseif ( $node->hasAttribute( 'v-else-if' ) ) {
+				$conditionString = $node->getAttribute( 'v-else-if' );
+				$node->removeAttribute( 'v-else-if' );
+				$condition = $this->app->evaluateExpression( $conditionString, $data );
+
+				if ( !$condition ) {
+					$nodesToRemove[] = $node;
+				}
+
+				$previousIfCondition = $previousIfCondition || $condition;
 			} elseif ( $node->hasAttribute( 'v-else' ) ) {
 				$node->removeAttribute( 'v-else' );
 

tests/php/TemplatingTest.php

@@ -192,6 +192,16 @@ public function testTemplateWithIfElseBlockAndNontruthfulCondition_ElseIsDisplay
 		$this->assertSame( '<p><a>else</a></p>', $result );
 	}
 
+	public function testTemplateWithElseIfBlockAndTruthfulCondition_IfAndElseRemoved() {
+		$result = $this->createAndRender(
+			'<p><a v-if="variable">if</a><a v-else-if="other_variable">else if</a>' .
+				'<a v-else>else</a></p>',
+			[ 'variable' => false, 'other_variable' => true ]
+		);
+
+		$this->assertSame( '<p><a>else if</a></p>', $result );
+	}
+
 	public function testTemplateWithForLoopAndEmptyArrayToIterate_NotRendered() {
 		$result = $this->createAndRender( '<p><a v-for="item in list"></a></p>', [ 'list' => [] ] );