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.
Related
Our application(based on Apache Wicket framework) actively uses Ajax in the form of AjaxButton, AjaxLinks etc. We want to encode the form data request in Base64 format before form submission and later decode it just after form submission. Basically, only the Base 64 encoded text will be a part of request data.
In other applications which uses javascript and java(struts framework), we have applied the encoding logic in javascript before document.form.submit and then on Java/server side , the decoding logic is applied.
Any idea how can we achieve the same in Apache wicket which follows Ajax form submission logic?
We tried AjaxCallListener but could not get hold of the request data. Hence, could not apply the encoding logic on the request
At the server side it should be easy to intercept the parameters' read by extending ServletWebRequest and overriding generatePostParameters() method.
Wicket uses jQuery to make the Ajax calls. But I see no way how to manipulate the data parameter before making the call.
I want to change the list of available values in a dropdown depending on the value selected in another dropdown and depending on values of certain fields in the model. I want to use JQuery to do this. The only hard part is checking the values in the model. I have been informed that I can do this using Ajax. Does anyone have any idea how I will approach doing this?
AJAX is indeed the technology your looking for. It is used to sent an asynchronous request from the client browser to the server.
jQuery has an ajax function that you can use to start such a request. In your controller you can have a regular method tagged with the [HttpPostAttribute] to respond to your AJAX request.
Most of the time you will return a JSON result from your Controller to your view. Think of JSON as something similar to XML but easier to work with from a browser. The browser will receive the JSON and can then parse the results to do something like showing a message or replacing some HTML in the browser.
Here you can find a nice example of how to use it all together.
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
I am developing an API using Codeigniter and Phils RESTserver. I know how to send the request body in normal Form format but how can I send it as a JSON object instead?
I do this now:
lastname=bond
I want to do this instead:
{"lastname" : "bond"}
I tried to just replace the Content type header from:
application/x-www-form-urlencoded
In to this:
application/json
This did not do anything. Codeigniter says the POST array is empty.
If I understood correctly you want to create a request that contains a JSON node inside the request body. Assuming this, I think it's not possible to create such a request using simple HTML form tags as your browser always will try to pack your input vars in a querystring like format.
You will need JavaScript to achive this (I think all popular libs like Scriptacoulous or JQuery comes with helper methods for this).
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).