restclient.php

<?php

/**
 * PHP REST Client
 * https://github.com/tcdent/php-restclient
 * (c) 2013 Travis Dent <tcdent@gmail.com>
 */

class RestClientException extends Exception {}

class RestClient implements Iterator, ArrayAccess {
    
    public $options;
    public $handle; // cURL resource handle.
    
    // Populated after execution:
    public $response; // Response body.
    public $headers; // Parsed reponse header object.
    public $info; // Response info object.
    public $error; // Response error string.
    
    // Populated as-needed.
    public $decoded_response; // Decoded response body. 
    private $iterator_positon;
    
    public function __construct($options=array()){
        $default_options = array(
            'headers' => array(), 
            'parameters' => array(), 
            'curl_options' => array(), 
            'user_agent' => "PHP RestClient/0.1.2", 
            'base_url' => NULL, 
            'format' => NULL, 
            'format_regex' => "/(\w+)\/(\w+)(;[.+])?/",
            'decoders' => array(
                'json' => 'json_decode', 
                'php' => 'unserialize'
            ), 
            'username' => NULL, 
            'password' => NULL
        );
        
        $this->options = array_merge($default_options, $options);
        if(array_key_exists('decoders', $options))
            $this->options['decoders'] = array_merge(
                $default_options['decoders'], $options['decoders']);
    }
    
    public function set_option($key, $value){
        $this->options[$key] = $value;
    }
    
    public function register_decoder($format, $method){
        // Decoder callbacks must adhere to the following pattern:
        //   array my_decoder(string $data)
        $this->options['decoders'][$format] = $method;
    }
    
    // Iterable methods:
    public function rewind(){
        $this->decode_response();
        return reset($this->decoded_response);
    }
    
    public function current(){
        return current($this->decoded_response);
    }
    
    public function key(){
        return key($this->decoded_response);
    }
    
    public function next(){
        return next($this->decoded_response);
    }
    
    public function valid(){
        return is_array($this->decoded_response)
            && (key($this->decoded_response) !== NULL);
    }
    
    // ArrayAccess methods:
    public function offsetExists($key){
        $this->decode_response();
        return is_array($this->decoded_response)?
            isset($this->decoded_response[$key]) : isset($this->decoded_response->{$key});
    }
    
    public function offsetGet($key){
        $this->decode_response();
        if(!$this->offsetExists($key))
            return NULL;
        
        return is_array($this->decoded_response)?
            $this->decoded_response[$key] : $this->decoded_response->{$key};
    }
    
    public function offsetSet($key, $value){
        throw new RestClientException("Decoded response data is immutable.");
    }
    
    public function offsetUnset($key){
        throw new RestClientException("Decoded response data is immutable.");
    }
    
    // Request methods:
    public function get($url, $parameters=array(), $headers=array()){
        return $this->execute($url, 'GET', $parameters, $headers);
    }
    
    public function post($url, $parameters=array(), $headers=array()){
        return $this->execute($url, 'POST', $parameters, $headers);
    }
    
    public function put($url, $parameters=array(), $headers=array()){
        return $this->execute($url, 'PUT', $parameters, $headers);
    }
    
    public function delete($url, $parameters=array(), $headers=array()){
        return $this->execute($url, 'DELETE', $parameters, $headers);
    }
    
    public function execute($url, $method='GET', $parameters=array(), $headers=array()){
        $client = clone $this;
        $client->url = $url;
        $client->handle = curl_init();
        $curlopt = array(
            CURLOPT_HEADER => TRUE, 
            CURLOPT_RETURNTRANSFER => TRUE, 
            CURLOPT_USERAGENT => $client->options['user_agent']
        );
        
        if($client->options['username'] && $client->options['password'])
            $curlopt[CURLOPT_USERPWD] = sprintf("%s:%s", 
                $client->options['username'], $client->options['password']);
        
        if(count($client->options['headers']) || count($headers)){
            $curlopt[CURLOPT_HTTPHEADER] = array();
            $headers = array_merge($client->options['headers'], $headers);
            foreach($headers as $key => $value){
                $curlopt[CURLOPT_HTTPHEADER][] = sprintf("%s:%s", $key, $value);
            }
        }
        
        if($client->options['format'])
            $client->url .= '.'.$client->options['format'];
        
        $parameters = array_merge($client->options['parameters'], $parameters);
        if(strtoupper($method) == 'POST'){
            $curlopt[CURLOPT_POST] = TRUE;
            $curlopt[CURLOPT_POSTFIELDS] = $client->format_query($parameters);
        }
        elseif(strtoupper($method) != 'GET'){
            $curlopt[CURLOPT_CUSTOMREQUEST] = strtoupper($method);
            $curlopt[CURLOPT_POSTFIELDS] = $client->format_query($parameters);
        }
        elseif(count($parameters)){
            $client->url .= strpos($client->url, '?')? '&' : '?';
            $client->url .= $client->format_query($parameters);
        }
        
        if($client->options['base_url']){
            if($client->url[0] != '/' || substr($client->options['base_url'], -1) != '/')
                $client->url = '/' . $client->url;
            $client->url = $client->options['base_url'] . $client->url;
        }
        $curlopt[CURLOPT_URL] = $client->url;
        
        if($client->options['curl_options']){
            // array_merge would reset our numeric keys.
            foreach($client->options['curl_options'] as $key => $value){
                $curlopt[$key] = $value;
            }
        }
        curl_setopt_array($client->handle, $curlopt);
        
        $client->parse_response(curl_exec($client->handle));
        $client->info = (object) curl_getinfo($client->handle);
        $client->error = curl_error($client->handle);
        
        curl_close($client->handle);
        return $client;
    }
    
    public function format_query($parameters, $primary='=', $secondary='&'){
        $query = "";
        foreach($parameters as $key => $value){
            $pair = array(urlencode($key), urlencode($value));
            $query .= implode($primary, $pair) . $secondary;
        }
        return rtrim($query, $secondary);
    }
    
    public function parse_response($response){
        $headers = array();
        $http_ver = strtok($response, "\n");
        
        while($line = strtok("\n")){
            if(strlen(trim($line)) == 0) break;
            
            list($key, $value) = explode(':', $line, 2);
            $key = trim(strtolower(str_replace('-', '_', $key)));
            $value = trim($value);
            if(empty($headers[$key]))
                $headers[$key] = $value;
            elseif(is_array($headers[$key]))
                $headers[$key][] = $value;
            else
                $headers[$key] = array($headers[$key], $value);
        }
        
        $this->headers = (object) $headers;
        $this->response = strtok("");
    }
    
    public function get_response_format(){
        if(!$this->response)
            throw new RestClientException(
                "A response must exist before it can be decoded.");
        
        // User-defined format. 
        if(!empty($this->options['format']))
            return $this->options['format'];
        
        // Extract format from response content-type header. 
        if(!empty($this->headers->content_type))
        if(preg_match($this->options['format_regex'], $this->headers->content_type, $matches))
            return $matches[2];
        
        throw new RestClientException(
            "Response format could not be determined.");
    }
    
    public function decode_response(){
        if(empty($this->decoded_response)){
            $format = $this->get_response_format();
            if(!array_key_exists($format, $this->options['decoders']))
                throw new RestClientException("'${format}' is not a supported ".
                    "format, register a decoder to handle this response.");
            
            $this->decoded_response = call_user_func(
                $this->options['decoders'][$format], $this->response);
        }
        
        return $this->decoded_response;
    }
}