Returns the first non-empty value in the collection after a filter is applied, or rewinds the
collection and returns the first value.
| public first ( callback $filter = null ) : mixed | ||
| $filter | callback | A closure through which collection values will be passed. If the return value of this function is non-empty, it will be returned as the result of the method call. If `null`, the collection is rewound (see `rewind()`) and the first item is returned. |
| return | mixed | Returns the first non-empty collection value returned from `$filter`. |
public function export(Source $dataSource, array $options = array())
{
$defaults = array('atomic' => true);
$options += $defaults;
list($data, $nested) = $this->_exportRecursive($dataSource, $options);
if ($options['atomic'] && $this->_exists) {
$data = array_intersect_key($data, $this->_modified + $nested);
}
if ($model = $this->_model) {
$name = null;
$options = array('atomic' => false) + $options;
$relations = new Collection(array('data' => $model::relations()));
$find = function ($relation) use(&$name) {
return $relation->fieldName === $name;
};
foreach ($this->_relationships as $name => $subObject) {
if (($rel = $relations->first($find)) && $rel->link == $rel::LINK_EMBEDDED) {
$data[$name] = $subObject->export($dataSource, $options);
}
}
}
return $data;
}
/**
* Tests that the `first()` method properly returns the first non-empty value.
*
* @return void
*/
public function testCollectionFirstFilter()
{
$collection = new Collection(array('data' => array(0, 1, 2)));
$result = $collection->first(function ($value) {
return $value;
});
$this->assertEqual(1, $result);
$collection = new Collection(array('data' => array('Hello', '', 'Goodbye')));
$result = $collection->first(function ($value) {
return $value;
});
$this->assertEqual('Hello', $result);
$collection = new Collection(array('data' => array('', 'Hello', 'Goodbye')));
$result = $collection->first(function ($value) {
return $value;
});
$this->assertEqual('Hello', $result);
$collection = new Collection(array('data' => array('', 'Hello', 'Goodbye')));
$result = $collection->first();
$this->assertEqual('', $result);
}
/**
* Overrides parent `first()` implementation to enable key/value-based filtering.
*
* @param mixed $filter In addition to a callback (see parent), can also be an array where the
* keys and values must match the property values of the objects being inspected.
* @return object Returns the first object found matching the filter criteria.
*/
public function first($filter = null)
{
return parent::first(is_array($filter) ? $this->_filterFromArray($filter) : $filter);
}
/**
* Tests the `ArrayAccess` interface implementation for traversing values.
*/
public function testArrayAccessTraversalMethods()
{
$collection = new Collection(array('data' => array('foo', 'bar', 'baz' => 'dib')));
$this->assertEqual('foo', $collection->current());
$this->assertEqual('bar', $collection->next());
$this->assertEqual('foo', $collection->prev());
$this->assertEqual('bar', $collection->next());
$this->assertEqual('dib', $collection->next());
$this->assertEqual('baz', $collection->key());
$this->assertTrue($collection->valid());
$this->assertFalse($collection->next());
$this->assertFalse($collection->valid());
$this->assertEqual('foo', $collection->rewind());
$this->assertTrue($collection->valid());
$this->assertEqual('dib', $collection->prev());
$this->assertTrue($collection->valid());
$this->assertEqual('bar', $collection->prev());
$this->assertTrue($collection->valid());
$this->assertEqual('dib', $collection->end());
$this->assertTrue($collection->valid());
$collection = new Collection(array('data' => array(0, 1, 2, 3, 4)));
$this->assertIdentical(0, $collection->first());
$this->assertIdentical(0, $collection->rewind());
$this->assertIdentical(1, $collection->next());
$this->assertIdentical(2, $collection->next());
$this->assertIdentical(3, $collection->next());
$this->assertIdentical(2, $collection->prev());
$this->assertIdentical(2, $collection->current());
$this->assertIdentical(3, $collection->next());
$this->assertIdentical(4, $collection->next());
$this->assertIdentical(3, $collection->prev());
$this->assertIdentical(4, $collection->next());
$this->assertTrue($collection->valid());
$this->assertFalse($collection->next());
$this->assertFalse($collection->valid());
$this->assertFalse($collection->current());
$this->assertIdentical(4, $collection->prev());
$this->assertTrue($collection->valid());
}
public function export(Source $dataSource, array $options = array())
{
$defaults = array('atomic' => true);
$options += $defaults;
$data = array();
$nested = array();
foreach ($this->_data as $key => $val) {
if (!is_object($val)) {
$data[$key] = $val;
continue;
}
$nestedOptions = $options;
switch (true) {
case is_a($val, $this->_classes['set']):
$nestedOptions = array('atomic' => false) + $options;
case is_a($val, $this->_classes['entity']):
if ($data[$key] = $val->export($dataSource, $nestedOptions)) {
$nested[$key] = true;
}
break;
}
}
if ($options['atomic'] && $this->_exists) {
$data = array_intersect_key($data, $this->_modified + $nested);
}
if ($model = $this->_model) {
$name = null;
$options = array('atomic' => false) + $options;
$relations = new Collection(array('data' => $model::relations()));
$find = function ($relation) use(&$name) {
return $relation->fieldName === $name;
};
foreach ($this->_relationships as $name => $subObject) {
if (($rel = $relations->first($find)) && $rel->link == $rel::LINK_EMBEDDED) {
$data[$name] = $subObject->export($dataSource, $options);
}
}
}
return $data;
}
