Merge pull request #137 from clue-labs/executor-docs

API documentation for ExecutorInterface

src/Query/ExecutorInterface.php

@@ -4,5 +4,40 @@
 
 interface ExecutorInterface
 {
+    /**
+     * Executes a query and will return a response message
+     *
+     * It returns a Promise which either fulfills with a response
+     * `React\Dns\Model\Message` on success or rejects with an `Exception` if
+     * the query is not successful. A response message may indicate an error
+     * condition in its `rcode`, but this is considered a valid response message.
+     *
+     * ```php
+     * $executor->query($query)->then(
+     *     function (React\Dns\Model\Message $response) {
+     *         // response message successfully received
+     *         var_dump($response->rcode, $response->answers);
+     *     },
+     *     function (Exception $error) {
+     *         // failed to query due to $error
+     *     }
+     * );
+     * ```
+     *
+     * The returned Promise MUST be implemented in such a way that it can be
+     * cancelled when it is still pending. Cancelling a pending promise MUST
+     * reject its value with an Exception. It SHOULD clean up any underlying
+     * resources and references as applicable.
+     *
+     * ```php
+     * $promise = $executor->query($query);
+     *
+     * $promise->cancel();
+     * ```
+     *
+     * @param Query $query
+     * @return \React\Promise\PromiseInterface<\React\Dns\Model\Message,\Exception>
+     *     resolves with response message on success or rejects with an Exception on error
+     */
     public function query(Query $query);
 }