silverstripe-framework/dev/YamlFixture.php

<?php

use Symfony\Component\Yaml\Parser;

/**
 * Uses Symfony's YAML component to parse a YAML document (see http://yaml.org).
 * YAML is a simple markup languages that uses tabs and colons instead of the more verbose XML tags, 
 * and because of this much better for developers creating files by hand.
 * 
 * The contents of the YAML file are broken into three levels:
 * - Top level: class names - Page and ErrorPage. This is the name of the dataobject class that should be created. 
 *   The fact that ErrorPage is actually a subclass is irrelevant to the system populating the database. 
 *   Each identifier you specify delimits a new database record. 
 *   This means that every record needs to have an identifier, whether you use it or not.
 * - Third level: fields - each field for the record is listed as a 3rd level entry. 
 *   In most cases, the field's raw content is provided. 
 *   However, if you want to define a relationship, you can do so using "=>"
 * 
 * There are a couple of lines like this:
 * <code>
 * Parent: =>Page.about
 * </code>
 * This will tell the system to set the ParentID database field to the ID of the Page object with the identifier
 * 'about'. This can be used on any has-one or many-many relationship. 
 * Note that we use the name of the relationship (Parent), and not the name of the database field (ParentID)
 *
 * On many-many relationships, you should specify a comma separated list of values.
 * <code>
 * MyRelation: =>Class.inst1,=>Class.inst2,=>Class.inst3
 * </code>
 * 
 * An crucial thing to note is that the YAML file specifies DataObjects, not database records. 
 * The database is populated by instantiating DataObject objects, setting the fields listed, and calling write(). 
 * This means that any onBeforeWrite() or default value logic will be executed as part of the test. 
 * This forms the basis of our testURLGeneration() test above.
 * 
 * For example, the URLSegment value of Page.staffduplicate is the same as the URLSegment value of Page.staff. 
 * When the fixture is set up, the URLSegment value of Page.staffduplicate will actually be my-staff-2.
 * 
 * Finally, be aware that requireDefaultRecords() is not called by the database populator - 
 * so you will need to specify standard pages such as 404 and home in your YAML file.
 * 
 * <code>
 * Page:
 *    home:
 *       Title: Home
 *    about:
 *       Title: About Us
 *    staff:
 *       Title: Staff
 *       URLSegment: my-staff
 *       Parent: =>Page.about
 *    staffduplicate:
 *       Title: Staff
 *       URLSegment: my-staff
 *       Parent: =>Page.about
 *    products:
 *       Title: Products
 * ErrorPage:
 *    404:
 *      Title: Page not Found
 *      ErrorCode: 404
 * </code>
 * 
 * @package framework
 * @subpackage core
 */
class YamlFixture extends Object {

	/**
	 * Absolute path to the .yml fixture file
	 *
	 * @var string
	 */
	protected $fixtureFile;

	/**
	 * String containing fixture
	 *
	 * @var String
	 */
	protected $fixtureString;

	/**
	 * @param String Absolute file path, or relative path to {@link Director::baseFolder()}
	 */
	public function __construct($fixture) {
		if(false !== strpos($fixture, "\n")) {
			$this->fixtureString = $fixture;
		} else {
			if(!Director::is_absolute($fixture)) $fixture = Director::baseFolder().'/'. $fixture;

			if(!file_exists($fixture)) {
				throw new InvalidArgumentException('YamlFixture::__construct(): Fixture path "' . $fixture
					. '" not found');
			}

			$this->fixtureFile = $fixture;
		}
		
		parent::__construct();
	}
	
	/**
	 * @return String Absolute file path
	 */
	public function getFixtureFile() {
		return $this->fixtureFile;
	}

	/**
	 * @return String Fixture string
	 */
	public function getFixtureString() {
		return $this->fixtureString;
	}

	/**
	 * Persists the YAML data in a FixtureFactory,
	 * which in turn saves them into the database.
	 * Please use the passed in factory to access the fixtures afterwards.
	 * 
	 * @param  FixtureFactory $factory
	 */
	public function writeInto(FixtureFactory $factory) {
		$parser = new Parser();
		if (isset($this->fixtureString)) {
			$fixtureContent = $parser->parse($this->fixtureString);
		} else {
			if (!file_exists($this->fixtureFile)) return;

			$contents = file_get_contents($this->fixtureFile);
			$fixtureContent = $parser->parse($contents);

			if (!$fixtureContent) return;
		}

		foreach($fixtureContent as $class => $items) {
			foreach($items as $identifier => $data) {
				if(ClassInfo::exists($class)) {
					$factory->createObject($class, $identifier, $data);
				} else {
					$factory->createRaw($class, $identifier, $data);
				}
			}
		}
	}

}