Can someone help me understand JSONP a little better?
I have a json file being out putted to a url. But due to same-origin policy I need to use JSONP. My question is do I need to change the actual JSON file or will using an ajax call with jquery, dataType: 'jsonp' do the work for me?
JSONP is nothing but, JSON with padding i.e. JSON wrapped by a function call. This format helps to pass the JSON data to java script.
JSON came into picture, when the JSON i.e. java script object can be used to represent the data, which was previously represented in the form of XML.
For example,
var data={...}; is data in json format. Whereas In JSONP, same data is written as getData(data);
In your scenario of ajax call, dataType:'jsonp', json data has to be passed as an argument to a function. You can access the response in that function.
If you could have provided some code, it will be easy to resolve your query. Information about JSONP is available on wikipedia here.
You will have to wrap your JSON data in a function call.
Like, someFunctionName(YOUR_EXISTING_JSON_DATA);
And,
use someFunctionName as jsonp callback
See, Cross-domain communications with JSONP
Related
I am new in Ajax . Want to use Ajax with Json . I am searching the tutorial for this and i find this.
I want to ask is i am in right direction ?
Is both things are same Ajax with Json and Ajax with dojo?
Not the same
Ajax is a technology that send request and accept data asynchronously(do not need to reload page).
You can use JSON or XML to send the data or just use the string.
When you do the Ajax request, any data type(like array, object, number..) except string will lost their data type and become string, so If you want to reserve their type, you must use data transmit format like JSON and XML.
Dojo just a library which have easier method for doing Ajax. You also can use jQuery, Angular,..Whatever even JavaScript native XMLHttpRequest.
If I am going to encrypt the data being passed by jQuery ajax prior to sending to the network (regardless if the network is SSL'd or not), where can I inject that functionality?
You can intercept all ajax queries initiated by jQuery, examine their content and change them (encrypt in your case) by using ajax prefilter in jQuery. With is approach you can modify all requests' contents at one place globally.
Details: http://api.jquery.com/jQuery.ajaxPrefilter/
Well, jQuery.ajax has a data field, which corresponds to the data sent in your request. So cleanest would be to set this field as a call to your encoding function.
$.ajax({
...
data: yourDataEncodingFunction(),
...
});
Remember data must be Key/Value pairs, so be sure that's what your function returns.
I have an $.ajax request that's sending the data in a serialize() and gets a json array in return. It works perfectly without any issues on Chrome develop's tools and Firefox's firebug. My question is, do I HAVE to send the data(user inputs) as json? I need json for the response but not for the request.
No, you send the data however you like but keep in mind how you send it will affect how you can retrieve it.
Also you aren't sending JSON in your request as .serialize() does not return JSON it returns a text string in standard URL-encoded notation.
No, you don't need to send it as JSON. You can send it in any other format, but your receiver will need to know how to interpret it. Usually people use JSON or XML since your receiver can easily parse these types of data.
You'll need to set the content-type, then you can tell the receiver how to process this content-type.
I'm calling a REST API somebody else created. It supports JSONP to facilitate cross domain access.
The response I get back from the service looks like:
mycallback('{"token": "123456789"}');
Notice the single quotes wrapping the JSON data; Passing it as a string rather than a raw object. JQuery can handle this, but other libraries seem to expect a raw object instead.
mycallback({"token": "123456789"});
The raw object parameter makes more sense to me since it avoids the need to parse the JSON data, but I want to know for sure before asking the maintainer of the API to make the adjustment:
Which is most correct?
Passing a javascript literal (second) as shown here is more correct as it avoids deserializing the string back to a javascript object.
Passing a string is obviously a bad thing - you have two choices (#1 is preferred):
Ask the developer of the JSONP service to send proper JSONp instead of a string
Make your callback function smart so it uses something like payload = JSON.parse(payload); in case payload is a string.
so still a newb to nodeJS and back end code in general. I need some help with ajax and node. For instance I have a function that goes like this
function random(response) {
var objToJson = {...};
response.write(objToJson);
response.end();
}
if instead of writing I want to pass this json object to another function as a response of an ajax call made to it how would that be?
Thanks for you help!
Node.js allows you to easy manipulate HTTP request and response objects.
Ajax still sends a HTTP request object and the Ajax onsuccess callback manipulates a HTTP response object.
Writing an object to a response for an ajax request allows your ajax success handler to manipulate that data.
There are abstraction libraries for RPC like now
It sounds like you want to return a javascript object to work with in your client-side code. While that's not possible directly (you can't send an object directly over HTTP; you're always serializing/deserialing in some fashion), you can certainly return a JSON payload and easily convert that to an in-memory javascript object. If that's what you're doing, you should set the response content type to application/json.
response.setHeader("Content-Type", "application/json");
If you're writing "pure" javascript (no framework wrapping XmlHttpRequest), you'll need to eval() the responseText to convert it to an object. If you're using something like jQuery, it will do that work for you (assuming you set the content type as suggested above).