[Summary view]

   1  <?php
   2  
   3  namespace GuzzleHttp\Promise;
   4  
   5  /**
   6   * A promise represents the eventual result of an asynchronous operation.
   7   *
   8   * The primary way of interacting with a promise is through its then method,
   9   * which registers callbacks to receive either a promise’s eventual value or
  10   * the reason why the promise cannot be fulfilled.
  11   *
  12   * @link https://promisesaplus.com/
  13   */
  14  interface PromiseInterface
  15  {
  16      const PENDING = 'pending';
  17      const FULFILLED = 'fulfilled';
  18      const REJECTED = 'rejected';
  19  
  20      /**
  21       * Appends fulfillment and rejection handlers to the promise, and returns
  22       * a new promise resolving to the return value of the called handler.
  23       *
  24       * @param callable $onFulfilled Invoked when the promise fulfills.
  25       * @param callable $onRejected  Invoked when the promise is rejected.
  26       *
  27       * @return PromiseInterface
  28       */
  29      public function then(
  30          callable $onFulfilled = null,
  31          callable $onRejected = null
  32      );
  33  
  34      /**
  35       * Appends a rejection handler callback to the promise, and returns a new
  36       * promise resolving to the return value of the callback if it is called,
  37       * or to its original fulfillment value if the promise is instead
  38       * fulfilled.
  39       *
  40       * @param callable $onRejected Invoked when the promise is rejected.
  41       *
  42       * @return PromiseInterface
  43       */
  44      public function otherwise(callable $onRejected);
  45  
  46      /**
  47       * Get the state of the promise ("pending", "rejected", or "fulfilled").
  48       *
  49       * The three states can be checked against the constants defined on
  50       * PromiseInterface: PENDING, FULFILLED, and REJECTED.
  51       *
  52       * @return string
  53       */
  54      public function getState();
  55  
  56      /**
  57       * Resolve the promise with the given value.
  58       *
  59       * @param mixed $value
  60       *
  61       * @throws \RuntimeException if the promise is already resolved.
  62       */
  63      public function resolve($value);
  64  
  65      /**
  66       * Reject the promise with the given reason.
  67       *
  68       * @param mixed $reason
  69       *
  70       * @throws \RuntimeException if the promise is already resolved.
  71       */
  72      public function reject($reason);
  73  
  74      /**
  75       * Cancels the promise if possible.
  76       *
  77       * @link https://github.com/promises-aplus/cancellation-spec/issues/7
  78       */
  79      public function cancel();
  80  
  81      /**
  82       * Waits until the promise completes if possible.
  83       *
  84       * Pass $unwrap as true to unwrap the result of the promise, either
  85       * returning the resolved value or throwing the rejected exception.
  86       *
  87       * If the promise cannot be waited on, then the promise will be rejected.
  88       *
  89       * @param bool $unwrap
  90       *
  91       * @return mixed
  92       *
  93       * @throws \LogicException if the promise has no wait function or if the
  94       *                         promise does not settle after waiting.
  95       */
  96      public function wait($unwrap = true);
  97  }