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PHP Class Neos\Eel\FlowQuery\FlowQuery

It is specifically implemented for being used inside Eel, the Embedded Expression Language for Flow. Essentially, a FlowQuery object is a container for an *ordered set* of objects of a certain type. On this container, *operations* can be applied (like filter(), children(), ...). All of these operations work on a *set*, that is, an operation usually expands or shrinks the set of objects. An operation normally returns a new FlowQuery instance with the operation applied, but there are also some operations like is(...) or count(), which return simple types like boolean or numbers. We call these operations *final operations*. Internal Workings ================= To allow for optimization, calling operations are not immediately executed. Instead, they are appended to a *list of operations*. Only if one tries to iterate over the FlowQuery object or calls a final operation, the operations get executed and the result is computed. Implementation of Operations ---------------------------- Operations are implemented by implementing the {@link OperationInterface} or, more commonly, subclassing the {@link Operations/AbstractOperation}. An operation must be *equivalence preserving*, that is, the following equation must always hold: applyAllOperations(context) = applyRemainingOperations(applyOperation(context)) While an operation is running, it can *add new operations* to the front of the operation queue (with {@link pushOperation()}), so for example count($filter) can first apply filter($filter), followed by count(). However, when doing this, great care must be applied by the operation developer in order to still have finite runs, and to make sure the operation is *equivalence preserving*. Furthermore, an operation can *pop* its following operations from the operation stack, and *peek* what the next operation is. It is up to the operation developer to ensure equivalence preservation. An operation may *never* invoke __call() on the FlowQuery object it receives; as this might lead to an undefined state; i.e. you are not allowed to do: $flowQuery->someOtherOperation() *inside* an operation. Final Operations ---------------- If an operation is final, it should return the resulting value directly. 显示文件 Open project: neos/flow-development-collection Class Usage Examples

Protected Properties

Property	Type	Description
$context	array | Traversable	the objects this FlowQuery object wraps
$operationResolver	Neos\Eel\FlowQuery\OperationResolverInterface
$operations	array	..', 'arguments' => array(...)) whereas the name is a string like 'children' and the arguments are a numerically-indexed array

Public Methods

Method	Description
__call ( string $operationName, array $arguments ) : FlowQuery	Add a new operation to the operation list and return the new FlowQuery object. If the operation is final, we directly compute the result and return the value.
__construct ( array | Traversable $context, array $operations = [] )	Construct a new FlowQuery object from $context and $operations.
allowsCallOfMethod ( string $methodName ) : boolean
count ( ) : integer	Implementation of the countable() interface, which is mapped to the "count" operation.
getContext ( ) : array | Traversable	Get the current context.
getIterator ( ) : ArrayIterator	Called when iterating over this FlowQuery object, triggers evaluation.
peekOperationName ( ) : string	Peek onto the next operation name, if any, or NULL otherwise.
popOperation ( ) : array	Pop the topmost operation from the stack and return it; i.e. the operation which should be executed next. The returned array has the form: array('name' => '.
pushOperation ( string $operationName, array $arguments )	Push a new operation onto the operations stack.
setContext ( array | Traversable $context )	Set the updated context with the operation result applied.
setOperationResolver ( Neos\Eel\FlowQuery\OperationResolverInterface $operationResolver )	Setter for setting the operation resolver from the outside, only needed to successfully run unit tests (hacky!)

Protected Methods

Method	Description
evaluateOperations ( ) : mixed	Evaluate operations

Method Details

Property Details