proposal/L31-php-intercetor-api-change.md

Title

• Author(s): ZhouyihaiDing
• Approver: mehrdada
• Status: Approved
• Implemented in: PHP
• Last updated: October 24, 2018
• Discussion at: https://groups.google.com/forum/#!searchin/grpc-io/L31|sort:date/grpc-io/DsjvtmeJJPU/QF2-99-oCAAJ

Abstract

This proposal introduces an interceptor API change in the gRPC PHP.

---

Background

gRPC PHP interceptor has ability to intercept each RPC by modifying method, argument, metadata and options. It is better if we can modify the deserialize.

The first reason is that since the interceptor can manipulate the method before the RPC starts, deserialize function should also be updated to be able to couple with the method when the response receives.

The second reason we do not need to hide the deserialize because hiding channel already satisfies the purpose of the interceptor.

Related Proposals

• PHP Client Interceptors

Proposal

Add $deserialize as the argument for the interceptor API.

Implementaion

The only change is that four methods inside the Interceptor take $deserialize as the argument. The new API looks like below:

class Interceptor{
  /**
     * @param string   $method       The name of the method to call
     * @param mixed    $argument     The argument to the method
     * @param string   $deserialize  A function that deserializes the response
     * @param array    $metadata     A metadata map to send to the server(optional)
     * @param array    $options      An array of call_options (optional)
     * @param function $continuation Used to invoke the next interceptor.
     *
     * @return \Closure A function which can create a UnaryCall
     */
  public function interceptUnaryUnary($method, $argument, $deserialize, array $metadata = [], array $options = [], $continuation){}

  public function interceptStreamUnary($method, $deserialize, array $metadata = [], array $options = [], $continuation){}

  public function interceptUnaryStream($method, $argument, $deserialize, array $metadata = [], array $options = [], $continuation){}

  public function interceptStreamStream($method, $deserialize, array $metadata = [], array $options = [], $continuation){}
}

Implementation

Implemented in PHP: add deserialze as the argument for the interceptor