PHP event functions

Definition

The following example shows the definition of a simple handler function, which is an event function:

<? php
function handler($event, $context) {
    return "hello world";
}        

Function name

handler must correspond to the handler field that you specify when you create a function. For example, if you set handler to index.handler when you create a function, Function Compute loads the handler function defined in the index.php file.

{
"key": "value"
}   

The $event parameter

The $event parameter is an input parameter of the function and indicates the data that is passed in when you call the event function. The value of this parameter is of the string type. PHP functions directly use the $event parameter that you specify, without performing any preprocessing. You can parse the $event parameter in the function as needed. For example, if a JSON string is passed in, you can convert it to an array. The following sample code shows the parsing process of the $event parameter.

In the code of the PHP function, the preceding $event parameter is parsed and value is returned.

<? php
function handler($event, $context) {
     $eventObj = json_decode($event, $assoc = true);
     return $eventObj['key'];
}           

The $context parameter

The $context parameter contains the runtime information of the function, such as the request ID (requestId) and the temporary identity credentials (securityToken). You can use the runtime information in your code. The value of the $context parameter is of the array type. The $context parameter is defined as follows:

[
  'requestId' => 'b1c5100f-819d-c421-3a5e-7782a27d8a33',
  'credentials' => [
    'accessKeyId' => 'STS.access_key_id',
    'accessKeySecret' => 'access_key_secret',
    'securityToken' => 'security_token',
  ],
  'function' => [
    'name' => 'my-func',
    'handler' => 'index.handler',
    'memory' => 128,
    'timeout' => 10,
  ],
  'service' =>[
     'name' => 'my-service',
     'logProject' => 'my-log-project',
     'logStore' => 'my-log-store',
     'qualifier' => 'qualifier',
     'versionId' => '1',
     'initializer' => 'index.initializer',
     'initializationTimeout' => 10,
  ],
  'region' => 'cn-shanghai',
  'accountId' => '123456'
]            

The following table lists the fields contained in the $context parameter.

Example

The temporary AccessKey pair is used to verify the identity and permissions of the request sender. When you use a temporary AccessKey pair to access other services such as OSS, you must specify the securityToken parameter. The following sample code shows how to upload a .txt file to an OSS bucket by using a temporary AccessKey pair.

<? php
use OSS\OssClient;
function handler($event, $context) { 
     $accessKeyId = $context["credentials"]["accessKeyId"];
     $accessKeySecret = $context["credentials"]["accessKeySecret"];
     $securityToken = $context["credentials"]["securityToken"];
     $endpoint = "oss-cn-shenzhen.aliyuncs.com";
     $ossClient = new OssClient($accessKeyId, $accessKeySecret, $endpoint, false, $securityToken);
     $bucket = "my-bucket";
     $object = "php.txt";
     $content = "Hello fc.";
     try {
        $ossClient->putObject($bucket, $object, $content);
     } catch (OssException $e) {
        print($e->getMessage());
     }
    return 'sucess';
};