Error decoding JSON input via json_decode - php

I'm writing my first web service, and I have a problem related to JSON data passing. I have my web service divided in two files: controller.php, which contains the service handler, and service.php, which contains the classes and methods to be served on request.
This is the acquisition fragment from controller.php:
public function atender() {
// pre-procesamos la petición
if (!empty($_POST)) {
if (!empty($_POST["class"]) && !empty($_POST["action"]) && !empty($_POST["function"])) {
$clase = ucwords($_POST["class"]);
$metodo = "{$_POST["action"]}{$this->obtenerMetodo($_POST["function"])}";
$id = (!empty($_POST["datos"]) ? stripslashes($_POST["datos"]) : null);
I can attend requests on both GET and POST mode (I use GET for methods not requiring authentication, like getCategories, getCategoryById, getProducts and getProductById. These are methods to get the dish categories and dishes in a sushi restaurant.)
For any of the GET requests, everything works like expected. My problem comes when I handle POST requests. I need to get all URL parameters in JSON, as this is to serve an iOS app, and JSON is the way we handle data to/from.
This is the processing fragment from service.php:
public function putUser($datos) {
if (!empty($datos)) {
$usuario = json_decode($datos);
$this->log .= implode("/", $usuario) . "\r\n";
In this case, $datos is the JSON-encoded data from the request. It's received as $id in controller.php (the code above). As it's my first web service, it's very probable I'm doing something really bad here, but I'm a bit blinded.
I've tried different variations of the service handling code. Using json_decode($datos, true) doesn't work either. I get
'Unexpected token <' as a response and, in raw form (using the advanced REST client from Google Chrome) it says: ''Warning: implode() [<a href='function.implode'>function.implode</a>]: Invalid arguments passed in /home/refine/public_html/sushigo/palma/service.php on line 344'.
I know SOAP is, usually, a better alternative to writing custom code like this but, for now, I need to stick with this code and implement a better alternative for my next project. Could you tell me what am I doing wrong?

The error message says, basically, that it is NOT a valid JSON - and such error messages are usually right.
Your error is somewhere in the sending / receiving code. Probably you send the JSON in one form and try to access it in some other way. Since I have no way of looking at the requests sent from the phone, I would guess that:
you send the data as application/json and try to receive it as an url encoded form. If you don't understand the difference, here's your problem.
you use stripslashes on the JSON data, which is wrong. UNLESS you have magic_quotes turned on, which would also be wrong (that is: both magic_quotes and stripslashes have to go).

Related

Posting Data to REST API using JSON and PHP

I've been looking around at similar topics on REST APIs but I am still having some confusion in my project, mostly with the PHP side of things.
USPS provides a REST API with functions that can be called via URL like this: https://epfws.usps.gov/ws/resources/epf/login
To make any call successfully, I have been told that a JSON object must be created and passed as a "POST parameter" with the expected values.
This is the JSON object that needs to be passed in this case:
obj=
{
"login":"loginExample",
"pword":"passwordExample"
}
I have also been given a PHP class that is supposed to manage these calls. This is the login function:
public function login ()
{
// Set up the parameters for a login attempt
$jsonData = array(
'login' => $this->loginUser,
'pword' => $this->loginPass,
);
// Make a login request
$jsonResponse = $this->pullResource
('/epf/login', 'POST', $jsonData);
return $jsonResponse;
}
So I have a few questions regarding this:
The document they sent says
"To make the request calls, a JSON object will need to be created and passed as a POST form parameter obj={jsonObject} for security reasons using content-type “application/x-www-form-urlencoded”."
I know that the login function contains the correct input values that USPS' REST API is wanting, but I'm not sure how to pass them as "obj", or how to apply the "content-type".
I have a "constant" defined at the top of my PHP script that looks like this:
const EPF_BASE_URL = 'https://epfws.usps.gov/ws/resources';
And I noticed in the actual functions that this part of the link is left out and they simply reference '/epf/login' as you can see above. Since "$this" contains lots of different values I'm wondering how it supposedly finds EPF_BASE_URL as needed. Is it similar to how 'using' directives work in C#?
What is the easiest way to call this function and display the result? This is my biggest question. Would I use a separate PHP class with an HTML form? I understand the concept of what it should do but I'm completely lost setting up a development environment for it.
I've been trying all of this with MAMP but would love to know if I'm on the right track or not.
That really depends on their API. Hopefully you get a string back that can be decoded to a JSON object (http://au.php.net/manual/en/function.json-decode.php). Some API might give a simple string that says 'SUCCESS' or 'FAIL'. You've got the code, so take a look at what $this->pullResponse() gives you.
If you've been given a PHP class that is supposed to support the API (hopefully from USPS), then it should already take care of putting the data in the form content, and ensuring is it submitted with the appropriate content-type.
A PHP const is more like a C# static string. It is very likely that the library will use the constant to create the end URL (i.e. EPF_BASE_URL . $resource). If you needed to run against a sand box environment, you could change that constant without having to change all the other code.
That's a very big question, because it depends on how you are programming your application. Procedural, MVC, existing frameworks, etc.
At the very least, you would set the loginUser and loginPass on the instantiated object, and call the login method`. You could then inspect the results, assuming the result is a JSON object, or use your favourite debugging method to see the contents.
I'm having a guess as the USPS API class name.
$uspsApi = new UspsApi();
$uspsApi->loginUser = 'username';
$uspsApi->loginPass = 'password';
$result = $uspsApi->login();
echo print_r($result, true);

HTTP protocol's PUT and DELETE and their usage in PHP

Introduction
I've read the following:
Hypertext Transfer Protocol (HTTP) is the life of the web. It's used every time you transfer a document, or make an AJAX request. But HTTP is surprisingly a relative unknown among some web developers.
The HTTP verbs comprise a major portion of our “uniform interface” constraint and provide us the action counterpart to the noun-based resource. The primary or most-commonly-used HTTP verbs (or methods, as they are properly called) are POST, GET, PUT, and DELETE.
Huh?
Well, we came to the point I lost track of things.
PUT and DELETE, they say. I've only ever heard of POST and GET and never saw something like $_PUT or $_DELETE passing by in any PHP code I've ever viewed.
My question
What are these methods (PUT) and (DELETE) for and if it's possible to use them in PHP, how would I go about this.
Note: I know this is not really a problem but I always grab a learning opportunity if I see one and would very much like to learn to use these methods in PHP if this is possible.
What are these methods (PUT) and (DELETE) for...
There are a lot of words to spend to explain this, and I'm not skilled enough to do it, but as already posted, a quick recap of what the HTTP specification describes.
The protocol basically says this:
use GET when you need to access a resource and retrieve data, and you don't have to modify or alter the state of this data.
use POST when you need to send some data to the server. Ex. from a form to save these data somewhere.
use HEAD when you need to access a resource and retrieve just the Headers from the response, without any resource data.
use PUT when you need to replace the state of some data already existing on that system.
use DELETE when you need to delete a resource (relative to the URI you've sent) on that system.
use OPTIONS when you need to get the communication options from a resource, so for checking allowed methods for that resource. Ex. we use it for CORS request and permissions rules.
You can read about the remaining two methods on that document, sorry I've never used it.
Basically a protocol is a set of rules you should use from your application to adhere to it.
... and if it's possible to
use them in PHP, how would I go about this.
From your php application you can retrieve which method was used by looking into the super global array $_SERVER and check the value of the field REQUEST_METHOD.
So from your php application you're now able to recognize if this is a DELETE or a PUT request, ex. $_SERVER['REQUEST_METHOD'] === 'DELETE' or $_SERVER['REQUEST_METHOD'] === 'PUT'.
* Please be also aware that some applications dealing with browsers that don't support PUT or DELETE methods use the following trick, a hidden field from the html form with the verb specified in its value attribute, ex.:
<input name="_method" type="hidden" value="delete" />
Follow an example with a small description on a possible way to handle those 2 http requests
When you (your browser, your client) request a resource to an HTTP server you must use one of the method that the protocol (HTTP) accepts. So your request needs to pass:
A METHOD
An Uri of the resource
Request Headers, like User-Agent, Host, Content-Length, etc
(Optional body of the request)
Now, while you would be able to get data from POST and GET requests with the respective globals ($_GET, $_POST), in case of PUT and DELETE requests PHP doesn't provide these fast access globals; But you can use the value of $_SERVER['REQUEST_METHOD'] to check the method in the request and handle your logic consequently.
So a PUT request would look like:
PUT /something/index.php
(body) maybe=aparameter
and you can access those data in PHP by reading the php://input stream, ex. with something like:
if ($_SERVER['REQUEST_METHOD'] === 'PUT') {
$myEntireBody = file_get_contents('php://input'); //Be aware that the stream can only be read once
}
and a DELETE request would look like:
DELETE /something/index.php?maybe=aparameter
and again you can build your logic after have checked the method:
if ($_SERVER['REQUEST_METHOD'] === 'DELETE') {
// do something
}
Please pay attention that a DELETE request has no Body and pay very attention to Response Status Code too (ex. if you received a PUT request and you've updated that resource without error you should return a 204 status -No content-).
Way to use PUT data from PHP:
$method = $_SERVER['REQUEST_METHOD'];
if ('PUT' === $method) {
parse_str(file_get_contents('php://input'), $_PUT);
var_dump($_PUT); //$_PUT contains put fields
}
PHP's $_GET and $_POST are poorly named. $_GET is used to access the values of query string parameters, and $_POST lets you access the request body.
Using query string parameters is not limited to GET requests, and other kinds of requests than just POST can come with a request body.
If you want to find out the verb used to request the page, use $_SERVER['REQUEST_METHOD'].
Most suitable place to use these (PUT and DELETE) methods is REST API. Where we use http methods to define the mode of operation for example you want to fetch any resources then you can use following:
GET http://api.example.com/employee/<any_id>
to add a new item:
POST http://api.example.com/employee/
to Update or Edit:
PUT http://api.example.com/employee/
to Delete an existing resource:
DELETE http://api.example.com/employee/1
etc.
Now on PHP side you just need to read what HTTP method used so that you can make an action according to that.
There are lots of libraries available which can do that for you.
What are these methods (PUT) and (DELETE)
There are described in the HTTP spec.
In a nutshell, and simplifying somewhat, PUT is for uploading a file to a URL and DELETE is for deleting a file from a URL.
never sawy something like $_PUT or $_DELETE passing by in any PHP code I've ever viewed
$_POST and $_GET are terribly named superglobals. $_POST is for data parsed from the request body. $_GET is for data parsed from the URL. There's nothing that strictly ties data in either of those places (especially the URL) to a particular request method.
DELETE requests only care about the URL's path, so there is no data to parse.
PUT requests usually care about the entire request body (not a parsed version of it) which you would access with file_get_contents('php://input');.
for and if it's possible to use them in PHP, how would I go about this.
You'd need to map the URL onto a PHP script (e.g. with URL rewriting), test the request method, work out what URL you were actually dealing with, and then write code to do the appropriate action.
$GLOBALS["_PUT"]=null;
if($_SERVER['REQUEST_METHOD'] == 'PUT') {
$form_data= json_encode(file_get_contents("php://input"));
$key_size=52;
$key=substr($form_data, 1, $key_size);
$acc_params=explode($key,$form_data);
array_shift($acc_params);
array_pop($acc_params);
foreach ($acc_params as $item){
$start_key=' name=\"';
$end_key='\"\r\n\r\n';
$start_key_pos=strpos($item,$start_key)+strlen($start_key);
$end_key_pos=strpos($item,$end_key);
$key=substr($item, $start_key_pos, ($end_key_pos-$start_key_pos));
$end_value='\r\n';
$value=substr($item, $end_key_pos+strlen($end_key), -strlen($end_value));
$_PUT[$key]=$value;
}
$GLOBALS["_PUT"]=$_PUT;
}
if (!function_exists("getParameter")){
function getParameter($parameter)
{
$value=null;
if(($_SERVER['REQUEST_METHOD'] == 'POST')&& (isset($_POST[$parameter]))){
$value=$_POST[$parameter];
}
else if(($_SERVER['REQUEST_METHOD'] == 'PUT')&& (isset($GLOBALS["_PUT"][$parameter])))
{
$value=$GLOBALS["_PUT"][$parameter];
}
else if(($_SERVER['REQUEST_METHOD'] == 'DELETE')&& (isset($_DELETE[$parameter]))){
$value=$_DELETE[$parameter];
}
else if(($_SERVER['REQUEST_METHOD'] == 'PATCH')&& (isset($_PATCH[$parameter]))){
$value=$_PATCH[$parameter];
}
else if(isset($_GET[$parameter])){
$value=$_GET[$parameter];
}
return $value;
}
}

Standardizing the JSON response

I have an application where information from the database is sent back as a JSON response.
Tailoring the jQuery side to handle each and every response seems like a lot of effort for little adaptability.
In what ways could the JSON format could be standardized ? Additionaly, is there a way to "slot in" a handler in jQuery ?
I've been thinking along the lines of something like this:
{
"replyCode": "OK"/"Error",
"replyMessage": "Operation successful"/"Could not connect",
"returnData": ... // Entities go here
}
Standardizing the JSON response is something that needs to be customized for each application; only you have the necessary data to decide exactly what actions should be supported and how they would be communicated over JSON.
As an example, in the past I have used both a "response sniffer" logic (where the handler checks for specific properties in the response and processes each one that exists in a specific manner) and a "command list" logic (where the response always contains an array of objects that describe specific actions that must be taken and the handler executes them) in this situation.
I don't believe that a reply code and message is necessary in most situations as the HTTP response header can communicate this information effectively.
Whatever you decide to do, .ajaxComplete (and its siblings .ajaxSuccess and .ajaxError) can be used to install global response handlers on the client side that run on completion of every request.
First, you should really take a look at the video RESTful API Design from the apigee guys. It contains a ton of good advice for RESTful APIs. Brian Mulloy gives also feedback on how responses should look like.
Next, you should take a look at some libs in php for developing RESTful APIs. Some of these gives you a solid way of how to return responses.
https://github.com/Respect/Rest
https://github.com/MArcJ/PHPRestService
https://github.com/kla/php-activerecord
or more https://github.com/search?q=php%20rest
With this you should good to go to build well RESTful APIs.
Why not have a central function that does the final echoing of the JSON as the response.
function returnJSON($code,$data=array()){
echo json_encode(
array(
'replyCode'=>$code,
'replyMessage'=>getReturnMessageByCode($code),
'returnData'=>$data
)
);
}
Now at the end of every AJAX call you make to retrieve this data, your PHP code would do something like this -
$data = fetchData();
if ($data){
returnJSON('OK',$data);
}else{
returnJSON('FAIL');
}
exit();
Standardizing your responses is a great idea and is also your responsibility. Unless your framework has other options its up to you to make your code as robust as possible.

Can't get 'http put' content in PHP

framework is here
http://luracast.com/products/restler/
i'm using restler as restful api for my work,
when i use backbone model save to a url, it sends and update my data as json by using 'HTTP PUT' request method, and i want to get a response from what i've putted...
if it's a HTTP POST request method i can use
// to getting content from a POST
$post_data = json_decode(file_get_contents('php://input'), true);
to get my content, but cant get anything from HTTP PUT
// can't get anything from a PUT
function putpatients($id) {
$post_data = file_get_contents('php://input');
$post_data = json_decode($post_data, true);
echo $post_data['name'];
}
the browser response blank
how do i return my data as json ???
As I commented on your question, php://input is a stream, if you read from it, it empties it.
I've never used Restler before but looking at the few examples provided in their download, it seems to indicate the submitted data is automatically passed as a parameter to your put handler..
In Restler's crud example, the Author class has a put request like this:
function put($id=NULL, $request_data=NULL) {
return $this->dp->update($id, $this->_validate($request_data));
}
so i'm guessing that restler has already read the php://input stream, and hence emptied it.
so, your put handler should maybe be more like in their example:
function putpatients($id, $request_data = NULL) {
/* do something with the $request_data */
var_dump($request_data);
}
Edit: There's actually a previous SO question from #deceze that talks about why reading twice from php://input doesn't work - for PUT requests - which explains why your code worked with a POST request. Either way, you should really use the facility provided by Restler rather than re-inventing the rest wheel.
Does the developer tool of your choice (firebug etc.) show a response?
If so it could help if you put echo json_encode($post_data['name']); instead of your echo.
try to use print_r() function for displaying the values of the variable example:
print_r($post_data);

translate from ASP to PHP

I am being forced to work with a database company that only support ASP.NET, despite my employers being well aware that I only code in PHP and the project doesn't have the time to learn the new syntax.
Documentation is scant, and meaning in thin on the ground. Can someone help translate what is happening in this script, so that I can think about doing it in PHP
<%
QES.ContentServer cs = new QES.ContentServer();
string state = "";
state = Request.Url.AbsoluteUri.ToString();
Response.Write(cs.GetXhtml(state));
%>
QES.ContentServer cs = new QES.ContentServer();
the code instantiates the class method ContentServer()
string state = "";
Explicit the type var state as string
state = Request.Url.AbsoluteUri.ToString();
here you get the REQUEST URI (as in php) the path and convert it to one line string and put in the before mentioned string statte var
Response.Write(cs.GetXhtml(state));
and here return the message without refresh the page (ajax).
The Request object wraps a bunch of information regarding the request from the client i.e. Browser capabilities, form or querystring parameters, cookies etc. In this case it is being used to retrieve the absolute URI using Request.Url.AbsoluteUri.ToString(). This will be the full request path including domain, path, querystring values.
The Response object wraps the response stream sent from the server back to the client. In this case it is being used to write the return of the cs.GetXhtml(state) call to the client as part of the body of the response.
QES.ContentServer appears to be a third party class and is not part of the standard .NET framework so you would have to get access to the specific API documention to find out what is for and what the GetXhtml method does exactly.
So, in a nutshell, this script is taking the full URI of the request from the client and returning the output from the GetXhtml back in the response.
It would look like this in PHP:
<?php
$cs = new QES_ContentServer(); //Not a real php class, but doesn't look like a native ASP.NET class either, still, it's a class instantiation, little Google shows it's a class for Qwam E-Content Server.
$state = ""; //Superfluous in PHP, don't need to define variables before use except in certain logic related circumstances, of course, the ASP.NET could have been done in one line like "string state = Request.Url.AbsoluteUri.ToString();"
$state = $_SERVER['REQUEST_URI']; //REQUEST_URI actually isn't the best, but it's pretty close. Request.Url.AbsoluteUri is the absolute uri used to call the page. REQUEST_URI would return something like /index.php while Request.Url.AbsoluteUri would give http://www.domain.com/index.php
//$state = $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']; or something similar might be better in this case given the above
echo $cs->GetXhtml($state); //GetXhtml would be a method of QES.ContentServer, Response.Write is like echo or print.
?>

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