Partial exceptions (#270)

* build: upgrade to stable dom release

* test: bind objects in arrays with bindList

* test: isolate first issue for #244

* feature: throw exception when no data-partial
for #244

* feature: throw exception when more than one data-partial
for #244

src/PartialExpander.php

@@ -15,7 +15,7 @@ public function expand(Element $context = null):array {
 			$context = $this->document->documentElement;
 		}
 
-		/** @var HTMLDocument[] $partialDocumentArray */
+		/** @var array<string, HTMLDocument> $partialDocumentArray */
 		$partialDocumentArray = [];
 		do {
 			$commentIni = new CommentIni($context);
@@ -30,7 +30,7 @@ public function expand(Element $context = null):array {
 		}
 		while(true);
 
-		foreach($partialDocumentArray as $partialDocument) {
+		foreach($partialDocumentArray as $extends => $partialDocument) {
 			if($currentTitle = $this->document->title) {
 				$partialDocument->title = $currentTitle;
 			}
@@ -40,7 +40,15 @@ public function expand(Element $context = null):array {
 				$partialDocument->documentElement,
 				true
 			);
-			$injectionPoint = $importedRoot->querySelector("[data-partial]");
+			$partialElementList = $importedRoot->querySelectorAll("[data-partial]");
+			if(count($partialElementList) > 1) {
+				throw new PartialInjectionMultiplePointException("The current view extends the partial \"$extends\", but there is more than one element marked with `data-partial`. For help, see https://www.php.gt/domtemplate/partials");
+			}
+			$injectionPoint = $partialElementList[0] ?? null;
+
+			if(!$injectionPoint) {
+				throw new PartialInjectionPointNotFoundException("The current view extends the partial \"$extends\", but there is no element marked with `data-partial`. For help, see https://www.php.gt/domtemplate/partials");
+			}
 
 // Move all the current document's content into the newly-imported injection point:
 			while($child = $this->document->body->firstChild) {

src/PartialInjectionMultiplePointException.php

@@ -0,0 +1,4 @@
+<?php
+namespace Gt\DomTemplate;
+
+class PartialInjectionMultiplePointException extends DomTemplateException {}

src/PartialInjectionPointNotFoundException.php

@@ -0,0 +1,4 @@
+<?php
+namespace Gt\DomTemplate;
+
+class PartialInjectionPointNotFoundException extends DomTemplateException {}

test/phpunit/PartialExpanderTest.php

@@ -7,6 +7,8 @@
 use Gt\DomTemplate\ModularContent;
 use Gt\DomTemplate\ModularContentFileNotFoundException;
 use Gt\DomTemplate\PartialExpander;
+use Gt\DomTemplate\PartialInjectionMultiplePointException;
+use Gt\DomTemplate\PartialInjectionPointNotFoundException;
 use Gt\DomTemplate\Test\TestFactory\DocumentTestFactory;
 
 class PartialExpanderTest extends ModularContentTestCase {
@@ -90,4 +92,31 @@ public function testExpand_recursive():void {
 		);
 		self::assertSame("This title was set in the inner partial view.", $document->title);
 	}
+
+	public function testExpand_noDataPartialElement():void {
+		$document = DocumentTestFactory::createHTML(DocumentTestFactory::HTML_EXTENDS_PARTIAL_VIEW);
+		$modularContent = self::mockModularContent(
+			"_partial", [
+// Here, the HTML_COMPONENT isn't expected, because there is no data-partial element.
+				"base-page" => DocumentTestFactory::HTML_COMPONENT,
+			]
+		);
+		$sut = new PartialExpander($document, $modularContent);
+		self::expectException(PartialInjectionPointNotFoundException::class);
+		self::expectExceptionMessage("The current view extends the partial \"base-page\", but there is no element marked with `data-partial`.");
+		$sut->expand();
+	}
+
+	public function testExpand_multipleDataPartialElements():void {
+		$document = DocumentTestFactory::createHTML(DocumentTestFactory::HTML_EXTENDS_PARTIAL_VIEW);
+		$modularContent = self::mockModularContent(
+			"_partial", [
+				"base-page" => DocumentTestFactory::HTML_INCORRECT_PARTIAL_VIEW,
+			]
+		);
+		$sut = new PartialExpander($document, $modularContent);
+		self::expectException(PartialInjectionMultiplePointException::class);
+		self::expectExceptionMessage("The current view extends the partial \"base-page\", but there is more than one element marked with `data-partial`.");
+		$sut->expand();
+	}
 }

test/phpunit/TestFactory/DocumentTestFactory.php

@@ -415,6 +415,32 @@ class DocumentTestFactory {
 	</footer>
 </body>
 </html>
+HTML;
+
+	const HTML_INCORRECT_PARTIAL_VIEW = <<<HTML
+<!doctype html>
+<html>
+<head>
+	<meta charset="utf-8" />
+	<title data-bind:test="title">My website</title>
+</head>
+<body>
+	<header>
+		<h1>My website!</h1>
+	</header>
+	<main data-partial>
+		The page content will go in here.
+	</main>
+	<div>
+		<article data-partial>
+			But, there's another partial element here, so things will break.
+		</article>	
+	</div>
+	<footer>
+		<p>Thank you for visiting!</p>
+	</footer>
+</body>
+</html>
 HTML;
 
 	const HTML_EXTENDS_PARTIAL_VIEW = <<<HTML
@@ -433,6 +459,7 @@ class DocumentTestFactory {
 </aside>
 HTML;
 
+
 	const HTML_INCORRECTLY_EXTENDS_PARTIAL_VIEW = <<<HTML
 <article>
 	<h1>Hello from within a sub-template!</h1>
@@ -485,7 +512,7 @@ class DocumentTestFactory {
 <h1>Component test</h1>
 <p>This test shows how a custom element can be injected into the document.</p>
 <custom-element />
-<p>If there's matching modular content in the _compnent directory, the above element will be filled with its content.</p>
+<p>If there's matching modular content in the _component directory, the above element will be filled with its content.</p>
 HTML;
 
 	const HTML_TRANSPORT_ROUTES = <<<HTML