silverstripe-framework/api/RestfulService.php
Andrew O'Neil 85d6566e32 #1730 - Caching in RestfulService (merged from branches/2.2.0, r44881)
git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/trunk@44915 467b73ca-7a2a-4603-9d3b-597d59a354a9
2007-11-15 22:40:36 +00:00

228 lines
6.2 KiB
PHP

<?php
/**
* RestfulService class allows you to consume various RESTful APIs.
* Through this you could connect and aggregate data of various web services.
*/
class RestfulService extends ViewableData {
protected $baseURL;
protected $queryString;
protected $rawXML;
protected $errorTag;
protected $checkErrors;
protected $cache_expire;
function __construct($base, $expiry=3600){
$this->baseURL = $base;
$this->cache_expire = $expiry;
}
/**
* Sets the Query string parameters to send a request.
* @param params An array passed with necessary parameters.
*/
function setQueryString($params=NULL){
$this->queryString = http_build_query($params,'','&');
}
protected function constructURL(){
return "$this->baseURL?$this->queryString";
}
/**
* Connects to the RESTful service and gets its response.
* TODO implement authentication via cURL for
*/
function connect(){
$url = $this->constructURL(); // url for the request
// check for file exists in cache
// set the cache directory
$cachedir = TEMP_FOLDER; // default silverstripe-cache
$cache_file = md5($url); // encoded name of cache file
$cache_path = $cachedir . "/$cache_file";
if((@file_exists("$cache_path") && ((@filemtime($cache_path) + $this->cache_expire) > (time())))){
$this->rawXML = file_get_contents($cache_path);
} else {
// not available in cache fetch from server
$ch = curl_init();
$timeout = 5;
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
$this->rawXML = curl_exec($ch);
curl_close($ch);
// save the response in cache
$fp = @fopen($cache_path,"w+");
@fwrite($fp,$this->rawXML);
@fclose($fp);
}
// Try using file_get_contents if cURL is not installed in your system.
// $this->rawXML = file_get_contents($url);
// results returned - from cache / live
if($this->rawXML != ""){
if($this->checkErrors == true) {
return $this->errorCatch($this->rawXML);
} else {
return $this->rawXML;
}
} else {
user_error("Invalid Response (maybe your calling to wrong URL or server unavailable)", E_USER_ERROR);
}
}
/**
* Gets attributes as an array, of a particular type of element.
* @params xml - the source xml to parse, this could be the original response received.
* @params collection - parent node which wraps the elements, if available
* @params element - element we need to extract the attributes.
* Example : <photo id="2636" owner="123" secret="ab128" server="2">
* returns id, owner,secret and sever attribute values of all such photo elements.
*/
function getAttributes($xml, $collection=NULL, $element=NULL){
$xml = new SimpleXMLElement($xml);
$output = new DataObjectSet();
if($collection)
$childElements = $xml->{$collection};
if($element)
$childElements = $xml->{$collection}->{$element};
if($childElements){
foreach($childElements as $child){
$data = array();
foreach($child->attributes() as $key => $value){
$data["$key"] = Convert::raw2xml($value);
}
$output->push(new ArrayData($data));
}
}
return $output;
}
/**
* Gets an attribute of a particular element.
* @params xml - the source xml to parse, this could be the original response received.
* @params collection - parent node which wraps the element, if available
* @params element - element we need to extract the attribute
* @params attr - name of the attribute
*/
function getAttribute($xml, $collection=NULL, $element=NULL, $attr){
$xml = new SimpleXMLElement($xml);
$attr_value = "";
if($collection)
$childElements = $xml->{$collection};
if($element)
$childElements = $xml->{$collection}->{$element};
if($childElements)
$attr_value = (string) $childElements[$attr];
return Convert::raw2xml($attr_value);
}
/**
* Gets set of node values as an array.
* When you get to the depth in the hierachchy use node_child_subchild syntax to get the value.
* @params xml - the source xml to parse, this could be the original response received.
* @params collection - parent node which wraps the elements, if available
* @params element - element we need to extract the node values.
*/
function getValues($xml, $collection=NULL, $element=NULL){
$xml = new SimpleXMLElement($xml);
$output = new DataObjectSet();
$childElements = $xml;
if($collection)
$childElements = $xml->{$collection};
if($element)
$childElements = $xml->{$collection}->{$element};
if($childElements){
foreach($childElements as $child){
$data = array();
$this->getRecurseValues($child,$data);
$output->push(new ArrayData($data));
}
}
return $output;
}
protected function getRecurseValues($xml,&$data,$parent=""){
$child_count = 0;
foreach($xml as $key=>$value)
{
$child_count++;
$k = ($parent == "") ? (string)$key : $parent . "_" . (string)$key;
if($this->getRecurseValues($value,$data,$k) == 0) // no childern, aka "leaf node"
$data[$k] = Convert::raw2xml($value);
}
return $child_count;
}
/**
* Gets a single node value.
* @params xml - the source xml to parse, this could be the original response received.
* @params collection - parent node which wraps the elements, if available
* @params element - element we need to extract the node value.
*/
function getValue($xml, $collection=NULL, $element=NULL){
$xml = new SimpleXMLElement($xml);
if($collection)
$childElements = $xml->{$collection};
if($element)
$childElements = $xml->{$collection}->{$element};
if($childElements)
return Convert::raw2xml($childElements);
}
function searchValue($xml, $node=NULL){
$xml = new SimpleXMLElement($xml);
$childElements = $xml->xpath($node);
if($childElements)
return Convert::raw2xml($childElements[0]);
}
function searchAttributes($xml, $node=NULL){
$xml = new SimpleXMLElement($xml);
$output = new DataObjectSet();
$childElements = $xml->xpath($node);
if($childElements)
foreach($childElements as $child){
$data = array();
foreach($child->attributes() as $key => $value){
$data["$key"] = Convert::raw2xml($value);
}
$output->push(new ArrayData($data));
}
//Debug::show($attr_value);
return $output;
}
}
?>