calling datasnap webservice from javascript into variable - web-services

I have created a Datasnap REST server.
A ReverseString method gets created by default that simply reverses the string passed to the method.
When I invoke the method using the browser URL:
http://dummydomain.com:81/datasnap/rest/TServerMethods1/ReverseString/ABC
I receive {"result":["CBA"]} as result. (server runs on port 81 and the parameter passed to the method is ABC)
I have tried the following code to get the result into a variable in javascript, but without success:
var options={
type: "GET",
url: "http://dummydomain.com:81/datasnap/rest/TServerMethods1/SayHello",
data: "ABC",
dataType: "json",
success: function(data) {
var json = JSON.stringify(data);
$("p").after('<div id="data1">Your result is: ' + json.result + '</div>');
}
}
$.ajax(options);
What am I doing wrong? In the end I need 'CBA' in a variable. If there are some good resources out there, please advise. I have been googling but everybody seem to do it in their own way.

Related

Coldfusion <cfsavecontent> variable displays correctly on page but does not save correctly to the DB

I have AJAX writing a result to <span id="response"></span>, which displays as expected. But, I need to convert to a CF variable so I can write the content to the database. Using
<cfsavecontent variable="JSONResponse"><span id="response"></span></cfsavecontent>
allows me to display the new JSONResponse variable on the page correctly, but when I take the same varible and write it to the database, it writes the <span id="response"></span> tag into the table - not the actual content. Does anyone have any suggestions? Thanks
Thanks #GSR & #Dan - I managed to work out a solution by forwarding on to a CFM page that writes to the DB, via another nested ajax post, based upon the response:
var postData = {username: "user#company.com", password: "Ruu3992032!883jj22uje"};
var ajaxResponse = $.ajax({
type: "post",
url: "https://api.company.com/v1/authenticate",
contentType: "application/json",
data: JSON.stringify( postData )
})
// When the response comes back, forward on to another cfm page with insert statement.
ajaxResponse.then(
function( apiResponse ){
$.ajax({
type: "post",
url: "WriteToDB.cfm",
data: jQuery.param({ payload: JSON.stringify( apiResponse ) }) ,
contentType: 'application/x-www-form-urlencoded; charset=UTF-8'
})
}
);

web service call with more than one parameter

In my app, I am calling .Net soap based webservices.
My web service call function is :
function CallService5() {
$.ajax({
type: "POST",
url: "http://10.0.2.2:51434/Service1.asmx/GetAllTableStatus",
dataType: "json",
data: "{}",
contentType: "application/json; charset=utf-8",
success: OnSuccess,
error: OnError
});
}
How can i add more than one parameter..?
I think you can use like this
var firstName = document.getElementById("txtFirstName").value;
var lastName = document.getElementById("txtLastName").value;
data : "{'firstName':firstName,'lastName':lastName}"
You can add parameters as query string in the url part of service
"http://10.0.2.2:51434/Service1.asmx/GetAllTableStatus?para =val"
You read the following articles:
it gives good solutions..
http://elegantcode.com/2009/02/21/javascript-arrays-via-jquery-ajax-to-an-aspnet-webmethod/
http://encosia.com/2008/03/27/using-jquery-to-consume-aspnet-json-web-services/

Get JSON data with jQuery from a .NET service: confused with ajax setup

I've just spent six hours trying to get this straight in my head and I haven't succeeded.
There's a HelloWorld .NET 3.5 web service on my local machine. Set up as required.
The service returns a List of custom structures.
I'm trying to consume it with jQuery 1.4.4.
When I try to do what the documentation says, I always get back an XML response from the service, which either causes parseerror in jQuery or gets passed as a dumb string to the success function. That is, however I combine dataType and accepts (which, according to the documentation, control how the received data is handled), I get an XML back.
But, when I do something that does not logically follow from the documentation, I successfully get my array of objects. That is, when I ignore dataType and accepts, and set contentType: "application/json; charset=utf-8" instead, it works fine. But contentType, according to the docs, control the data being sent to the server, not received.
In code:
$.ajax(
{
type: "GET",
url: "http://localhost:52624/Service1.asmx/HelloWorld",
dataType: "json",
//accepts can be anything, or it can be missing, doesn't matter, only depends on dataType
success: function(data, textStatus, jqXHR) {...},
error: function(jqXHR, textStatus, errorThrown) {...}
}
)
Result: error handler called, textStatus = parseerror.
$.ajax(
{
type: "GET",
url: "http://localhost:52624/Service1.asmx/HelloWorld",
dataType: "application/json",
//accepts can be anything, or it can be missing, doesn't matter, only depends on dataType
success: function(data, textStatus, jqXHR) {...},
error: function(jqXHR, textStatus, errorThrown) {...}
}
)
Result: Web service returns XML, it's passed to the success handler as string.
$.ajax(
{
type: "GET",
url: "http://localhost:52624/Service1.asmx/HelloWorld",
accepts: "json", // or "application/json"
success: function(data, textStatus, jqXHR) {...},
error: function(jqXHR, textStatus, errorThrown) {...}
}
)
Result: Web service returns XML, it's parsed and passed as IXMLDOMDocument2.
$.ajax(
{
type: "GET",
url: "http://localhost:52624/Service1.asmx/HelloWorld",
contentType: "application/json; charset=utf-8",
success: function(data, textStatus, jqXHR) {...},
error: function(jqXHR, textStatus, errorThrown) {...}
}
)
Result: Web service returns JSON, which gets partially parsed by jQuery (numbers and strings are parsed into properties of objects, but dates remain in the form of "/Date(1303003305724)/").
Questions:
Do I understand jQuery specs at all? Why is the parameter that is said to control sent data in fact controls received data?
What am I doing blatantly wrong?
What's the last step to get dates parsed by jQuery, too?
Looks like I'm going to answer that myself.
I'm not saying the following is the absolute truth. Rather, it is what I have found to be working.
First of all, I found three articles that explained a lot:
Using jQuery to Consume ASP.NET JSON Web Services
ASMX ScriptService mistake – Invalid JSON primitive
3 mistakes to avoid when using jQuery with ASP.NET AJAX
In short, the problem with .NET web services is that you have to call them in a special way:
Using a POST request (but see below), and
Providing Content-Type of application/json; charset=utf-8
This is by design and for security reasons.
The latter may not be avoided, you must provide that content type. And because content type does dictate how parameters are encoded in the request, you must encode your parameters in JSON.
This is where jQuery jumps in. For no reason jQuery would ignore contentType and encode your parameters in application/x-www-form-urlencoded. At which point the web service will dislike you for saying "here is JSON" and providing form-encoded stuff instead.
In these articles, the author recommends that you play a trick with jQuery by enclosing your JSON data in another pair of quotes so that it's interpreted as a string and doesn't get fiddled with by jQuery:
$.ajax({
type: "POST",
url: "ServiceName.asmx/WebMethodName",
data: "{'fname':'dave','lname':'ward'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function(msg) {...}
});
This does work indeed.
Also, if you don't have any data, you still must provide an empty JSON object, {}, because if you don't, jQuery will not set Content-Length, and without Content-Length the web service will dislike you again (more security reasons).
However.
Since FW 3.5, it is possible to use GET with JSON-enabled .NET services. At which point you might wonder how JSON-encoded parameters align with GET requests. Here's how.
If your web service doesn't have any parameters, the call is simple:
$.ajax(
{
type: "GET",
url: "ServiceName.asmx/WebMethodName",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function(data, textStatus, jqXHR) {...}
}
);
And if there are parameters, then the call is also simple. What you have to do is provide additional quotes around parameters that should have them! This is because you want these quotes to appear as part of the form-encoded request. This way the form-encoded request will look sort of like json-encoded one:
$.ajax(
{
type: "GET",
url: "ServiceName.asmx/WebMethodName",
contentType: "application/json; charset=utf-8",
data: {DatePlaced:'"2011-05-13"'},
dataType: "json",
success: function(data, textStatus, jqXHR) {...}
}
);
This request will result in a request that looks similar to:
GET /ServiceName.asmx/WebMethodName?DatePlaced="2011-05-13" HTTP/1.1
Content-Type: application/json; charset=utf-8
Note the quotes that are required for JSON-like GET requests, but cause an error if you meant to ask for XML.
when posting to asp.net web services you always have to set the content type to that - it's their way of preventing json hijacking.
About the dates the easiest solution would be to return the dates as strings dealing date types on the client side will be a huge PITA (from my experience at least).
I think you don't understand the jQuery specs: (Specs)
dataType
Default: Intelligent
Guess (xml, json, script, or html)
The type of data that you're expecting
back from the server. If none is
specified, jQuery will try to infer it
based on the MIME type of the response...
Now. Look at your various cases.
Case 1: dataType: "json".
You receive "xml" but declare "json" => you get a parseerror because you can't parse xml as if it was json.
Case 2: dataType: "application/json".
"application/json" is NOT a valid data type, so jQuery defaults to string.
Case 3: No dataType.
jQuery makes its best guess, which turns out fine in your case.
Case 4: contentType: "application/json; charset=utf-8"
You ask for json data, and you don't specify the dataType. In this case you are lucky the Webservice does return json data, and jQuery guesses correctly that the data are in json format.
About the date formating, you want to look at:
How do I format a Microsoft JSON date?

What is the best way to send multiple parameters to a webservice from a client, which is a scripting language?

I would appreciate if someone can point me the recommended ways of passing multiple (say 10) parameters from client to a webservice. I have the requirements for the server side, so once I figure out the best way to pass data, I can expose the webmethod on the server side (.NET). FYI, I have a SOAP client that is implemented in Javascript. Thanks in advance!
JQuery:
function AddLocation(ParentID, name, name2, code) {
$.ajax({
type: "POST",
url: "../server.asmx/Save",
data: "{'ID':'0','ParentID':'" + ParentID + "','Name':'" + name + "','Name2':'" + name2 + "','Code':'" + code + "'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (data) {
var result = data.d;
//more code here
}
});
}

Using jquery $.get to call an external web service

I am calling the following jQuery code on page load to test the concept of calling an external web service from the client. The data object in the success callback is always empty. What am I doing wrong?
$.ajax({
url: "http://www.google.com/search",
type: 'GET',
data: { q: "green tea" },
success: function(data) { alert("Data Loaded: " + data) },
dataType: "text/html"
});
It's the same-origin policy you're hitting here, it's specifically in place to prevent cross-domain calls for security reasons. The expected behavior is for the response to be empty here.
You either need to fetch the data via JSONP or get the data via your own domain, your server proxying the request.
It's worth noting Google has a full JavaScript API for searching that you may want to check out for doing this.
browser dont allow you to make cross domain request(a security feature). there is a hack for that with a limitation that you can get only json as response.
----the trick (hack)----
using jquery(or javascript)you create a new script tag and with src="url_of_third_party?", when that request is made you get json from cross site.
jQuery('body').append('<script src="cross_site_url" type="text/javascript"></script>');
or simply you can do this
$.ajax({
url: "http://www.google.com/search",
type: 'GET',
data: { q: "green tea" },
success: function(data) { alert("Data Loaded: " + data) },
dataType: "jsonp",
});
note: dataType=jsonp