Exceptions
Exceptions overview
All exceptions thrown in HTTP_Request2 are instances of HTTP_Request2_Exception. Since release 2.0.0beta1, HTTP_Request2 tries to throw a specialized subclass of that class and provide an error code when possible.
Checking for exception subclass and error code can help your application identify transient failures (e.g. HTTP_Request2_MessageException with error code HTTP_Request2_Exception::TIMEOUT). You can also use this information to display a user friendly error message instead of displaying Exception message that is more programmer friendly.
The following HTTP_Request2_Exception subclasses are available:
- HTTP_Request2_NotImplementedException
- Exception thrown in case of missing package features.
- HTTP_Request2_LogicException
- Exception that represents error in the program logic. These are usually thrown before request even starts. This exception implies an error on part of the programmer, like passing an invalid argument to a method or trying to use Curl Adapter when curl extension is disabled. They are unlikely to happen in production except for those dealing with local files.
- HTTP_Request2_ConnectionException
- Exception thrown when connection to a web or proxy server fails.
- HTTP_Request2_MessageException
- Thrown when sending or receiving HTTP message fails (this implies that connection succeeded, at least). Can be caused by network problems (e.g. timeout) or remote server sending invalid data.
Error codes
Subclasses of HTTP_Request2_Exception can contain two error codes:
- Package error code, one of the constants described below. Can be accessed via getCode() method.
- Native error code, as returned by an underlying PHP extension used by the Adapter. Specifically, these are the error codes returned by stream_socket_client() for Socket Adapter and curl_errno() for Curl Adapter. Native error code can be accessed via HTTP_Request2_Exception::getNativeCode().
The following package error codes are currently used:
| Constant | Meaning |
|---|---|
| HTTP_Request2_Exception::INVALID_ARGUMENT | An invalid argument was passed to a method. |
| HTTP_Request2_Exception::MISSING_VALUE | Some required value was not available. |
| HTTP_Request2_Exception::MISCONFIGURATION | Request cannot be processed due to errors in PHP configuration (e.g. trying to use disabled PHP extension). |
| HTTP_Request2_Exception::READ_ERROR | Error reading the local file. |
| Constant | Meaning |
|---|---|
| HTTP_Request2_Exception::MALFORMED_RESPONSE | Server returned a response that does not conform to HTTP protocol. This means that even status line of response message could not be parsed. |
| HTTP_Request2_Exception::DECODE_ERROR | Failure decoding Content-Encoding or Transfer-Encoding of response. |
| HTTP_Request2_Exception::TIMEOUT | Operation timed out. |
| HTTP_Request2_Exception::TOO_MANY_REDIRECTS | Number of redirects exceeded 'max_redirects' configuration parameter. |
| HTTP_Request2_Exception::NON_HTTP_REDIRECT | Redirect to a protocol other than http(s)://. |