Using The API¶

Target group: Developers

Table of Contents

Introduction ¶

With the extension’s API you can define the structured markup with PHP. For example, create a class which gets an Extbase model as input and defines the markup. Then instantiate the class in an action of your controller.

Each type model class in the PHP namespace Brotkrueml\Schema\Model\Type inherits from the abstract class Brotkrueml\Schema\Core\Model\AbstractType which defines methods to set and get the properties of a model.

There are currently over 600 models available.

Starting With An Example ¶

Let’s start with a simple example. Imagine you describe a person on a plugin’s detail page that you want to enrich with structured markup. First you have to create the schema model:

$person = new \Brotkrueml\Schema\Model\Type\Person();

As you see, the schema type Person maps to the model Person. You can use every accepted type of the schema.org vocabulary.

Surely you will need to add some properties:

$person
   ->setId('http://example.org/#person-42')
   ->setProperty('givenName', 'John')
   ->setProperty('familyName', 'Smith')
   ->setProperty('gender', 'http://schema.org/Male');
;

That was easy … let’s go on and define an event the person attends:

$event = (new \Brotkrueml\Schema\Model\Type\Event())
   ->setProperty('name', 'Fancy Event')
   ->setProperty('image', 'https:/example.org/event.png')
   ->setProperty('url', 'https://example.org/')
   ->setProperty('isAccessibleForFree', true)
   ->setProperty('sameAs', 'https://twitter.com/fancy-event')
   ->addProperty('sameAs', 'https://facebook.com/fancy-event')
;

Now we have to connect the two types together:

$person->setProperty('attendee', $event);

The defined models are ready to embed on the web page. The schema manager does that for you:

$schemaManager = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(
   \Brotkrueml\Schema\Manager\SchemaManager::class
);
$schemaManager->addType($person);

That’s it … if you call the according page the structured markup is embedded automatically into the head section:

{
   "@context": "http://schema.org",
   "@type": "Person",
   "@id": "http://example.org/#person-42",
   "givenName": "John",
   "familyName": "Smith",
   "gender": "http://schema.org/Male",
   "attendee": {
      "@type": "Event",
      "name": "Fancy Event",
      "image": "https://example.org/event.png",
      "url": "https://example.org",
      "isAccessibleForFree": "http://schema.org/True",
      "sameAs": ["https://twitter.com/fancy-event", "https://facebook.com/fancy-event"]
   }
}

The Model In-Depth ¶

Available Type Model Methods ¶

The type models expose several methods:

`->setId(string $id)`¶

The method sets the unique ID of the model. With the ID, you can cross-reference types on the same page or between different pages (and even between different web sites) without repeating all the properties.

It is common to use an IRI as ID like in the above example. Please keep in mind that the ID should be consistent between changes of the properties, e.g. if a person marries and the name is changed. The person is still the same, so the IRI should be.

The IRI is no URL, so it is acceptable to give a “404 Not Found” back if you call it in a browser.

Parameter: string $id: The unique id to set.
Return value: Reference to the model itself.

`->getId()`¶

Gets the id of the type model.

Parameter: none
Return value: A previously set id or null (if not defined).

`->setProperty(string $propertyName, $propertyValue)`¶

Call this method to set a property or overwrite a previously one.

Parameters

string $propertyName: The property name to set. If the property does not exist in the model, an exception is thrown.
string|array|bool|AbstractType|null $propertyValue: The value of the property to set. This can be a string, a boolean, another model or an array of strings, booleans or models. Also null is possible to clear the property value.

Return value

Reference to the model itself.

`->addProperty(string $propertyName, $propertyValue)`¶

Call this method if you want to add a value to an existing one. In the example above, you can see that addProperty() is used to add a second value to the sameAs property.

Calling the addProperty() method on a property that has no value assigned has the same effect as calling setProperty(). So you can safely use it, e.g. in a loop, to set some values on a property.

Parameters

string $propertyName: The property name to set. If the property does not exist in the model, an exception is thrown.
string|array|bool|AbstractType|null $propertyValue: The value of the property to set. This can be a string, a boolean, another model or an array of strings, booleans or models. Also null is possible to clear the property value.

Return value

Reference to the model itself.

`->setProperties(array $properties)`¶

Set multiple properties at once.

Parameter

array $properties: The properties to set. The key of the array is the property name, the value is the property value. Allowed as values are the same as with the method ->setProperty().

Return value

Reference to the model itself.

`->getProperty(string $propertyName)`¶

Get the value of a property.

Parameter

string $propertyName: The property name to get the value from. If the property name does not exist in the model, an exception is thrown.

Return value

The value of the property (string, bool, model, array of strings, array of models, null).

`->hasProperty(string $propertyName)`¶

Check whether the property name exists in a particular model.

Parameter

string $propertyName: The property name to check.

Return value

true, if the property exists and false, otherwise.

`->clearProperty(string $propertyName)`¶

Resets the value of the property (set it to null).

Parameter

string $propertyName: The property name to set. If the property does not exist in the model, an exception is thrown.

Return value

Reference to the model itself.

`->getPropertyNames()`¶

Get the names of all properties of the model.

Return value: Array of all property names of the model.

`->isEmpty()`¶

Checks, whether all properties of the models are empty.

Parameter: none
Return value: true if all properties have an empty value, false otherwise.

Note

If at least one property has a boolean value, the method isEmpty() returns false, because it is mapped on the type http://schema.org/False or http://schema.org/True.

Other Useful APIs ¶

Boolean Data Type ¶

Boolean property values are mapped to the according schema terms http://schema.org/True or http://schema.org/False. You can also use the Brotkrueml\Schema\Model\DataType\Boolean class yourself. It exposes two public constants:

::FALSE: Has the value http://schema.org/False.
::TRUE: Has the value http://schema.org/True.

and one static method:

::convertToTerm(bool $value): string: This method returns the according schema term.

List Of Types ¶

If you need a list of the available types or a subset of them, you can call methods on the Brotkrueml\Schema\Provider\TypesProvider class.

`->getTypes()`¶

Get all available type names.

Parameter

none

Return value

Array, sorted alphabetically by type name.

Example

$types = (new \Brotkrueml\Schema\Provider\TypesProvider())->getTypes();

`->getWebPageTypes()`¶

Get the WebPage type and its descendants.

Parameter: none
Return value: Array, sorted alphabetically by type name.

`->getWebPageElementTypes()`¶

Get the WebPageElement type and its descendants.

Parameter: none
Return value: Array, sorted alphabetically by type name.

`->getContentTypes()`¶

The types useful for an editor are returned as an array, sorted alphabetically.

The following types are filtered out:

BreadcrumbList
WebPage and descendants
WebPageElement and descendants
WebSite

Parameter: none
Return value: Array, sorted alphabetically by type name.