Develop Reference

Implementing Ajax calls for a REST API

I have built a back end REST API using Slim Framework and followed the REST format as close as I could.
Once I started working on the Front End I realized that AJAX works great with parameters and not paths
(param file?param=value , paths file/object/method/id)
I am planning on out sourcing or building an APP with xamarin or other 3rd party to consume the API, but for now a Alpha test will be done with HTML and AJAX calls.
Example call example.com/user/test or example.com/advertiser/2
So how do I query the API, do I just concat URL strings?
.ajax({ ... url : 'example.com/user/'+user ...});
EDIT:
Yes I know AJAX is domain sensitive, and Yes I am using verbs GET,POST,PUT and DELETE.
What is going on is the following :
When passing variables in an AJAX request they get appended as
PARAMS example.com/users/?user=Pogrindis
in an REST API at least as far as I read it goes
example.com/users/Pogrindis that's a path
reference parse.com/docs/rest#general-quick

Ajax has set definitions how to do this : https://api.jquery.com/jQuery.ajax/
Your passing user as a param, over get // post method and you are specifying what you expect back.
If i understood the question correctly you are looking at something like:
$.ajax({ url: 'example.com/user/',
data: {user: user}, // Params being sent
type: 'post',// Or get
dataType: 'json' // Or whatever you have
success: function(output) {
//.. do what you like
}
});
There should be no problem.
The data being passed into it will append to the url for GET-requests, i think thats what you mean.. Your data object can be constructed before sending via ajax.
There needs to be a route to query for data. Unless you define some flag on the server to point to the correct location, then you could pass through a route param but you need to have a pointer URL. Building the route can be painful, and subsequent calls will be more challenging but you can do it ?

After doing some research here is a solution used
FRONT END
$.ajax({
url: '/user/'+getid,
data: getdatastring,
type: 'GET',
datatype: 'json',
cache: false,
success: function(data) {
data = JSON.parse(data);
}
});
BACK END
SLIM PHP FRAMEWORK
$app->put('/user/:id', function($id) use ($app,$_pdo) {
$obj = new dbModel($_pdo);
$objApi = new Controller($obj);
$arrParams = json_decode($app->request()->getBody(),true);
$arrUser= $objApi->getUserInfo($id,$arrParams);
print json_encode($arrUser);
});

How do I do an ajax call to a database using Javascript, a URL and a key

I have been given a url of type xxxx.xxxxx.com as well as a key of type FGHyehgvc787vbhj
in order to gain read-only access to an sql database and retrieve data from it using javascript.
I have no prior experience with databases and maybe my question will sound completely stupid but I was wondering how can I combine the above information in order to get access to the database (e.g. do an ajax call and retrieve data from it..)
I'm familiar with doing ajax calls to a webpage and getting data from it using jQuery, as in :
$.ajax(/*url of website*/, function (data)
{
var dataRetrieved = $(data);
// do something with the data retrieved...
});
so I was wondering whether there is something equivalent to the above when it comes to making an ajax call to a database, using however a key.
Thank you for any help, and please delete this post if you find it completely pointless and excuse me in advance for that by the way.

It is usually very bad design to allow client side code to interact with your database in any way. This can be a huge security issue. Generally you will want your server side code to do this (e.g PHP, node, etc.). You would send a request to your server with client side code, and the server side code would do the actual work of updating the database.

you can create a wcf service and call that service through ajax, that wont be huge security issue.
try this
$.ajax({
cache: false,
type: "GET",
async: false,
data: {},
url: http:xxxxxxxxxxxx.svc/webBinding/Result?metaTag=" + meta,
contentType: "application/json; charset=utf-8",
dataType: "json",
crossDomain: true,
success:function(result){},
error: function(){alert(err);}
});

Use this
$.ajax({
url: 'path/to/server-side/script.php', /*url*/
data: '', /* post data e.g name=christian&hobbie=loving */
type: '', /* POST|GET */
complete: function(d) {
var data= d.responseTXT;
/* Here you can use the data as you like */
$('#elementid').html(data);
}
});
Hope this helps...

Consuming web service in HTML

I have created a web service and saved its .wsdl file. I want to consume this service in my HTML file by providing its URL.
Can anybody tell me how to call the URL in HTML and use it?
Like its done here.
http://www.codeproject.com/Articles/14610/Calling-Web-Services-from-HTML-Pages-using-JavaScr/
The only difference is my web service does not have an extention like "asmx?wsdl".
Does that makes any difference.
I followed that tutorial too but it does not produce any output.
Thank You////

You definitly should get familiar with AJAX.
You could use the ajax functionalities provided by jQuery. That's the easiest way, I assume. Take a look at http://api.jquery.com/jQuery.ajax/
You can use this like
$.ajax({
url: "urltoyourservice.xml"
dataType: "xml",
}).done(function(data) {
console.log(data);
});
HTML itself cannot consume a webservice. Javascript ist definitely needed.
The existence of your WSDL File looks like you are probably using a XML format as the return of the web service. You have to deal with XML in javascript. Therefore take a look at Tim Downs explanation.
But keep in mind, that your web service URL must be available under the same domain as your consumption HTML-File. Otherwise you'll receive a cross-site-scripting error.

yes you can use ajax but keep in mind you wont be able to make a request across domains. Consuming web services should be done in server side.
To further gain more knowledge about this, read How do I call a web service from javascript

function submit_form(){
var username=$("#username").val();
var password=$("#password").val();
var data = { loginName: username, password:password };
$.ajax( {
type: "POST",
url:"Paste ur service address here",
data: JSON.stringify(data),
contentType: "application/json; charset=utf-8",
dataType: "json",
async: false,
success: function(data){
var value = data.d;
if(value.UserID != 0){
alert.html('success');
}
},
error: function (e) {
}
});
}
Try this it will help

Get prayer time JSON data using JQUERY and Ajax

I want to READ JSON data using Jquery ana Ajax from this link
http://praytime.info/getprayertimes.php?lat=31.950001&lon=35.9333&gmt=180&m=3&y=2013&school=0&format=json&callback=?
and this is my code:
$(document).ready(function() {
var strUser ="http://praytime.info/getprayertimes.php?lat=31.950001&lon=35.9333&gmt=180&m=3&y=2013&school=0&format=json&callback=?";
$.ajax({
url: strUser ,
dataType: 'jsonp',
success: function(data){
jQuery.each(data, function(){
alert("yes");
});
}
});
});
I tried this code with other links , and it's correct, but from the specified link I don't get any out put, can you help me??

The url you are trying to access with JSONP doesnot support it. The server will need to return the response as JSON, but also wrap the response in the requested call back. So a way to solve this problem is using a server side proxy, which fetches the response from the specified url and passes it on to your client side js, like:
$.ajax({
type: "GET",
url: url_to_yourserverside_proxy,
dataType: "json",
success: function( data ) {
console.log(data);
}
});
where
url_to_yourserverside_proxy is a server side file that fetches response from the url specified

URL is outputting json but for cross domain need jsonp.
Not all API's provide jsonp. If cross domain API doesn't provide jsonp and isn't CORS enabled you will need to use a proxy to retrieve data due to same origin policy

Ajax message best practices

Say I need to use ajax to asynchronously ask the server for an xml file containing relevant data. What is the best practice on what this message should look like? Should it be a string like get_data or something similar? Should it be xml? I don't really need long polling since its a one-time (or close to it) request.
Thanks.

You can use standard a HTTP Post or Get to send the request to your server. If you don't need to specify any parameters to your server side script ( user_id, etc ) then simply appending get_data as a url parameter will work fine.
http://www.domain.com/script?get_data
If you need to send any parameters to the server in order to retrieve data it is best to encode the parameters in JSON or XML and send them as the data portion of your AJAX request. With JQuery and JSON data:
$.ajax({
type: "GET",
url: "http://www.domain.com/script",
data: { key: "value", key2: "value2" },
async: true,
dataType: "json",
success: function( data, textStatus ) {
someCallbackFucntion( data );
}
});

The message should be the url.
For example: http://www.example.com/get_data could return the data you need in the format you need (xml, json).
If you need some other data, use an other url. http://www.example.com/someotherdata

It really depends on the purpose, if everything else is XML, go for XML. Personally I perfer JSON (for the client-side at least).
In a recent implementation I made, I used a simple POST request where the key represented the type of data and the value contained the time-interval it should return.
Which could be (jQuery):
$.ajax({
type: "POST",
url: "http://www.domain.com/script",
data: { stock_value: "last_30_min", group_activity: "last_20" },
async: true,
dataType: "json",
success: function( data, textStatus ) {
someCallbackFucntion( data );
}
});
A server-side controller would then handle the request appropriately and the client-side would know what data to expect when it returned. Also the key and value would be humanly readable from both client- and server-side. Of course the time-intervals could be a timestamp or otherwise, whatever fits the need.