Promise
Table of Contents
Namespaces
Interfaces
Classes
Functions
- resolve() : PromiseInterface<string|int, T>
- Creates a promise for the supplied `$promiseOrValue`.
- reject() : PromiseInterface<string|int, never>
- Creates a rejected promise for the supplied `$reason`.
- all() : PromiseInterface<string|int, array<string|int, T>>
- Returns a promise that will resolve only once all the items in `$promisesOrValues` have resolved. The resolution value of the returned promise will be an array containing the resolution values of each of the items in `$promisesOrValues`.
- race() : PromiseInterface<string|int, T>
- Initiates a competitive race that allows one winner. Returns a promise which is resolved in the same way the first settled promise resolves.
- any() : PromiseInterface<string|int, T>
- Returns a promise that will resolve when any one of the items in `$promisesOrValues` resolves. The resolution value of the returned promise will be the resolution value of the triggering item.
- set_rejection_handler() : callable(Throwable): void|null
- Sets the global rejection handler for unhandled promise rejections.
Functions
resolve()
Creates a promise for the supplied `$promiseOrValue`.
resolve(PromiseInterface<string|int, T>|T $promiseOrValue) : PromiseInterface<string|int, T>
If $promiseOrValue is a value, it will be the resolution value of the
returned promise.
If $promiseOrValue is a thenable (any object that provides a then() method),
a trusted promise that follows the state of the thenable is returned.
If $promiseOrValue is a promise, it will be returned as is.
Parameters
- $promiseOrValue : PromiseInterface<string|int, T>|T
Tags
Return values
PromiseInterface<string|int, T>reject()
Creates a rejected promise for the supplied `$reason`.
reject(Throwable $reason) : PromiseInterface<string|int, never>
If $reason is a value, it will be the rejection value of the
returned promise.
If $reason is a promise, its completion value will be the rejected
value of the returned promise.
This can be useful in situations where you need to reject a promise without throwing an exception. For example, it allows you to propagate a rejection with the value of another promise.
Parameters
- $reason : Throwable
Return values
PromiseInterface<string|int, never>all()
Returns a promise that will resolve only once all the items in `$promisesOrValues` have resolved. The resolution value of the returned promise will be an array containing the resolution values of each of the items in `$promisesOrValues`.
all(iterable<string|int, PromiseInterface<string|int, T>|T> $promisesOrValues) : PromiseInterface<string|int, array<string|int, T>>
Parameters
- $promisesOrValues : iterable<string|int, PromiseInterface<string|int, T>|T>
Tags
Return values
PromiseInterface<string|int, array<string|int, T>>race()
Initiates a competitive race that allows one winner. Returns a promise which is resolved in the same way the first settled promise resolves.
race(iterable<string|int, PromiseInterface<string|int, T>|T> $promisesOrValues) : PromiseInterface<string|int, T>
The returned promise will become infinitely pending if $promisesOrValues
contains 0 items.
Parameters
- $promisesOrValues : iterable<string|int, PromiseInterface<string|int, T>|T>
Tags
Return values
PromiseInterface<string|int, T>any()
Returns a promise that will resolve when any one of the items in `$promisesOrValues` resolves. The resolution value of the returned promise will be the resolution value of the triggering item.
any(iterable<string|int, PromiseInterface<string|int, T>|T> $promisesOrValues) : PromiseInterface<string|int, T>
The returned promise will only reject if all items in $promisesOrValues are
rejected. The rejection value will be an array of all rejection reasons.
The returned promise will also reject with a React\Promise\Exception\LengthException
if $promisesOrValues contains 0 items.
Parameters
- $promisesOrValues : iterable<string|int, PromiseInterface<string|int, T>|T>
Tags
Return values
PromiseInterface<string|int, T>set_rejection_handler()
Sets the global rejection handler for unhandled promise rejections.
set_rejection_handler(callable(Throwable): void|null $callback) : callable(Throwable): void|null
Note that rejected promises should always be handled similar to how any
exceptions should always be caught in a try + catch block. If you remove
the last reference to a rejected promise that has not been handled, it will
report an unhandled promise rejection. See also the reject() function
for more details.
The ?callable $callback argument MUST be a valid callback function that
accepts a single Throwable argument or a null value to restore the
default promise rejection handler. The return value of the callback function
will be ignored and has no effect, so you SHOULD return a void value. The
callback function MUST NOT throw or the program will be terminated with a
fatal error.
The function returns the previous rejection handler or null if using the
default promise rejection handler.
The default promise rejection handler will log an error message plus its stack trace:
// Unhandled promise rejection with RuntimeException: Unhandled in example.php:2
React\Promise\reject(new RuntimeException('Unhandled'));
The promise rejection handler may be used to use customize the log message or
write to custom log targets. As a rule of thumb, this function should only be
used as a last resort and promise rejections are best handled with either the
then() method, the
catch() method, or the
finally() method.
See also the reject() function for more details.
Parameters
- $callback : callable(Throwable): void|null