Fix recipe import from some WordPress sites

I want to import recipes from a site that uses WordPress Recipe Maker

At least on this site, the schema is structured like so:

{
  "@schema": "https://schema.org/",
  "@graph": [
    { /* blah */ },
    { /* blah */ },
    { "@type": "Recipe", "otherStuff": True }
  ]
}

Notably missing is the @schema on the Recipe object. It's intended
to be inherited from the parent, but HttpJsonLdParser didn't support
this kind of inheritance.

Well, now it does! =)

Signed-off-by: Nathaniel <I@nathaniel.land>

lib/Helper/HTMLParser/HttpJsonLdParser.php

@@ -122,9 +122,17 @@ class HttpJsonLdParser extends AbstractHtmlParser {
 	 */
 	private function mapGraphField(array &$json) {
 		if (isset($json['@graph']) && is_array($json['@graph'])) {
-			$tmp = $this->searchForRecipeInArray($json['@graph']);
+			// Sometimes the context is set once on the top level object for children to inherit
+			$parentSetsContext = isset($json['@context']) &&
+			                     $this->jsonService->isSchemaContext($json['@context']);
+
+			$tmp = $this->searchForRecipeInArray($json['@graph'], $parentSetsContext);
 
 			if ($tmp !== null) {
+				// If the child wants to inherit context from parent, copy it on down
+				if ($parentSetsContext && !isset($tmp['@context'])) {
+					$tmp['@context'] = $json['@context'];
+				}
 				$json = $tmp;
 			}
 		}
@@ -153,13 +161,14 @@ class HttpJsonLdParser extends AbstractHtmlParser {
 	/**
 	 * Search for a recipe object in an array
 	 * @param array $arr The array to search
+	 * @param bool $haveSchemaContext Whether Schema context is given, so child needn't set it
 	 * @return array|NULL The found recipe or null if no recipe was found in the array
 	 */
-	private function searchForRecipeInArray(array $arr): ?array {
+	private function searchForRecipeInArray(array $arr, bool $haveSchemaContext = false): ?array {
 		// Iterate through all objects in the array ...
 		foreach ($arr as $item) {
 			// ... looking for a recipe
-			if ($this->jsonService->isSchemaObject($item, 'Recipe', true, false)) {
+			if ($this->jsonService->isSchemaObject($item, 'Recipe', !$haveSchemaContext, false)) {
 				// We found a recipe in the array, use it
 				return $item;
 			}

lib/Service/JsonService.php

@@ -21,13 +21,13 @@ class JsonService {
 	 * @return bool true, if $obj is an object and optionally satisfies the type check
 	 */
 	public function isSchemaObject($obj, ?string $type = null, bool $checkContext = true, bool $uniqueType = true): bool {
-		if (!is_array($obj)) {
+		if (! is_array($obj)) {
 			// Objects must bve encoded as arrays in JSON
 			return false;
 		}
 
 		if ($checkContext) {
-			if (!isset($obj['@context']) || !preg_match('@^https?://schema\.org/?$@', $obj['@context'])) {
+			if (!isset($obj['@context']) || ! $this->isSchemaContext($obj['@context'])) {
 				// We have no correct context property
 				return false;
 			}
@@ -64,6 +64,16 @@ class JsonService {
 		return (strcmp($obj['@type'], $type) === 0);
 	}
 
+	/**
+	 * Check if the value of a schema key matches that of a schema.org object
+	 *
+	 * @param string $context The value of some object's @schema property
+	 * @return bool true, if the schema matches that of a schema.org object
+	 */
+	public function isSchemaContext(string $context): bool {
+		return preg_match('@^https?://schema\.org/?$@', $context);
+	}
+
 	/**
 	 * Check if $obj is a schema.org object and contains a named property.
 	 *