Zend_Http_Response

Introduction

Zend_Http_Response provides easy access to an HTTP responses message, as well as a set of static methods for parsing HTTP response messages. Usually, Zend_Http_Response is used as an object returned by a Zend_Http_Client request.

In most cases, a Zend_Http_Response object will be instantiated using the fromString() method, which reads a string containing a HTTP response message, and returns a new Zend_Http_Response object:

Example #1 Instantiating a Zend_Http_Response Object Using the Factory Method

  1. $str = '';
  2. $sock = fsockopen('www.example.com', 80);
  3. $req =     "GET / HTTP/1.1\r\n" .
  4.         "Host: www.example.com\r\n" .
  5.         "Connection: close\r\n" .
  6.         "\r\n";
  7.  
  8. fwrite($sock, $req);
  9. while ($buff = fread($sock, 1024))
  10.     $str .= $sock;
  11.  
  12. $response = Zend_Http_Response::fromString($str);

You can also use the contractor method to create a new response object, by specifying all the parameters of the response:

public function __construct($code, $headers, $body = null, $version = '1.1', $message = null)

  • $code: The HTTP response code (eg. 200, 404, etc.)

  • $headers: An associative array of HTTP response headers (eg. 'Host' => 'example.com')

  • $body: The response body as a string

  • $version: The HTTP response version (usually 1.0 or 1.1)

  • $message: The HTTP response message (eg 'OK', 'Internal Server Error'). If not specified, the message will be set according to the response code

Boolean Tester Methods

Once a Zend_Http_Response object is instantiated, it provides several methods that can be used to test the type of the response. These all return Boolean TRUE or FALSE:

  • isSuccessful(): Whether the request was successful or not. Returns TRUE for HTTP 1xx and 2xx response codes

  • isError(): Whether the response code implies an error or not. Returns TRUE for HTTP 4xx (client errors) and 5xx (server errors) response codes

  • isRedirect(): Whether the response is a redirection response or not. Returns TRUE for HTTP 3xx response codes

Example #2 Using the isError() method to validate a response

  1. if ($response->isError()) {
  2.   echo "Error transmitting data.\n"
  3.   echo "Server reply was: " . $response->getStatus() .
  4.        " " . $response->getMessage() . "\n";
  5. }
  6. // .. process the response here...

Accessor Methods

The main goal of the response object is to provide easy access to various response parameters.

  • getStatus(): Get the HTTP response status code (eg. 200, 504, etc.)

  • getMessage(): Get the HTTP response status message (eg. "Not Found", "Authorization Required")

  • getBody(): Get the fully decoded HTTP response body

  • getRawBody(): Get the raw, possibly encoded HTTP response body. if the body was decoded using GZIP encoding for example, it will not be decoded.

  • getHeaders(): Get the HTTP response headers as an associative array (eg. 'Content-type' => 'text/html')

  • getHeader($header): Get a specific HTTP response header, specified by $header

  • getHeadersAsString($status_line, $br): Get the entire set of headers as a string. If $status_line is TRUE (default), the first status line (eg. "HTTP/1.1 200 OK") will also be returned. Lines are broken with the $br parameter (Can be, for example, "<br />". Default "\n")

  • asString($br): Get the entire response message as a string. Lines are broken with the $br parameter (Can be, for example, "<br />". Default "\n"). You can also use the magic method __toString() when casting the object as a string. It will then proxy to asString().

Example #3 Using Zend_Http_Response Accessor Methods

  1. if ($response->getStatus() == 200) {
  2.   echo "The request returned the following information:<br />";
  3.   echo $response->getBody();
  4. } else {
  5.   echo "An error occurred while fetching data:<br />";
  6.   echo $response->getStatus() . ": " . $response->getMessage();
  7. }

Note: Always check return value
Since a response can contain several instances of the same header, the getHeader() method and getHeaders() method may return either a single string, or an array of strings for each header. You should always check whether the returned value is a string or array.

Example #4 Accessing Response Headers

  1. $ctype = $response->getHeader('Content-type');
  2. if (is_array($ctype)) $ctype = $ctype[0];
  3.  
  4. $body = $response->getBody();
  5. if ($ctype == 'text/html' || $ctype == 'text/xml') {
  6.   $body = htmlentities($body);
  7. }
  8.  
  9. echo $body;

Static HTTP Response Parsers

The Zend_Http_Response class also includes several internally-used methods for processing and parsing HTTP response messages. These methods are all exposed as static methods, which means they can be used externally, even if you do not need to instantiate a response object, and just want to extract a specific part of the response.

  • Zend_Http_Response::extractCode($response_str): Extract and return the HTTP response code (eg. 200 or 404) from $response_str

  • Zend_Http_Response::extractMessage($response_str): Extract and return the HTTP response message (eg. "OK" or "File Not Found") from $response_str

  • Zend_Http_Response::extractVersion($response_str): Extract and return the HTTP version (eg. 1.1 or 1.0) from $response_str

  • Zend_Http_Response::extractHeaders($response_str): Extract and return the HTTP response headers from $response_str as an array

  • Zend_Http_Response::extractBody($response_str): Extract and return the HTTP response body from $response_str

  • Zend_Http_Response::responseCodeAsText($code, $http11): Get the standard HTTP response message for a response code $code. For example, will return "Internal Server Error" if $code is 500. If $http11 is TRUE (default), will return HTTP/1.1 standard messages - otherwise HTTP/1.0 messages will be returned. If $code is not specified, this method will return all known HTTP response codes as an associative (code => message) array.

Apart from parser methods, the class also includes a set of decoders for common HTTP response transfer encodings:

  • Zend_Http_Response::decodeChunkedBody($body): Decode a complete "Content-Transfer-Encoding: Chunked" body

  • Zend_Http_Response::decodeGzip($body): Decode a "Content-Encoding: gzip" body

  • Zend_Http_Response::decodeDeflate($body): Decode a "Content-Encoding: deflate" body

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