If an oembed provider is only outputting json and xml, does that mean it is impossible to use this via client side javascript? ($.ajax request to the provider)?
Can we only use oembed providers that allow for a jsonp callback in javascript?
Thanks,
Wesley
you cannot use ajax across different domains.
Jsonp is an option, other option is to have a server side script which will fetch the data from the provider and then make an ajax call to that script to return the fetched data
Related
I have a scenario where I need to fetch JSON response data from an API in a different domain. Lets say the requesting domain is ClientDomain and the API domain in APIDomain.
Now I know that this can be achieved using Access-Control-Allow-Origin header in the API server and then using a client ajax marking the CrossDomain attribute as true, etc.
All my search leads either to modify the API settings to add the Access-Control-Allow-Origin header or do a proxy coding in backend server code. But in my case, I don't have access to the API code and I can't change anything there. I'm able to do a proxy read from C# controller code and fetch data from the APIDomain. I want to know how this can be achieved only with Javascript/Jquery in my current scenario.
Edit: Is there a way to do proxy-ing via Javascript/Jquery?
Any help would be great!
Make an API/page on ClientDomain and access it via Javascript/Jquery. In that API/page call the API on APIDomain and return its data.
I am trying to pull information from Google Finances stock screener. There is no official api, so I am just making a get request to the same URL that they use on the site. I am using the URL at the bottom of the question, it can get a bit long. I can go to the url myself and it will give me a text file with the JSON information. In my javascript I am using $.getJSON on the url to get the screener results. But I get a Access-Control-Allow-Origin error, so I change output=json to output=jsonp&callback=?. But it only returns ();. From what I can tell this means that it is not set up on the other end to respond to a jsonp request and cannot return the proper information.
I have also tried output=json&callback=?, which produces the (); and output=json&callback=callbackFunction and output=json&callback=callbackFunction which both give me Access-Control-Allow-Origin.
Is there any way that I can make this work?
https://www.google.com/finance?output=json&start=0&num=20&noIL=1&q=[currency%20%3D%3D%20%22USD%22%20%26%20%28%28exchange%20%3D%3D%20%22OTCMKTS%22%29%20%7C%20%28exchange%20%3D%3D%20%22OTCBB%22%29%20%7C%20%28exchange%20%3D%3D%20%22NYSEMKT%22%29%20%7C%20%28exchange%20%3D%3D%20%22NYSEARCA%22%29%20%7C%20%28exchange%20%3D%3D%20%22NYSE%22%29%20%7C%20%28exchange%20%3D%3D%20%22NASDAQ%22%29%29%20%26%20%28market_cap%20%3E%3D%200%29%20%26%20%28market_cap%20%3C%3D%200.1%29]&restype=company&ei=GLyhVKmcDpOb8gbm7IGQAQ
If the service doesn't provide a JSONP endpoint or use CORS to grant you permission to access some other kind of endpoint, then there is no way to access the data using client side code.
Use server side code instead. You can use that to present the data to your client side code.
I am trying cross domain request from my js file.
First,I was trying JSONP but my target domain URL is not support it. It return plain JSON object.
I am authorize person to access my target domain URL. but i can not modify it as per JSONP response.
SO how can i get JSON response from my target domain URL?
Without modifying a bit the server side there is not much you can do. The general policy is to not to allow cross domain requests.
There are few things worth mentioning though:
Try changing the server side so it will support JSONP.
If the HTTP response contains Access-Control-Allow-Origin header then you can communicate with it with normal AJAX. This feature is supported in modern browsers only. Check this out for more info.
You can do the cross domain requests with Flash and/or WebSockets. However server does have to support them.
I have always done it with jsonp, by passing a callback b/c services return json, if call back is passed then it will wrap all json in callback else they will simple return json.
But in your case
You can look up with this article
http://www.webdevdoor.com/jquery/cross-domain-browser-json-ajax/
Don't know what type application you are developing. But in ASP.NET you can do it by using a proxy page
These links may be helpful:
http://www.codeproject.com/Articles/667611/ASP-NET-Proxy-Page-Used-for-Cross-Domain-Requests
http://encosia.com/use-asp-nets-httphandler-to-bridge-the-cross-domain-gap/
https://gist.github.com/jkresner/3982746
I understand the way to make an ajax call in YUI 3 is using the IO utility.
I want to get the address of a location from Google's geocoding API.
<script type="text/javascript"><!--
YUI().use('io-base', function(Y) {
function complete(id, o) {
var data = o.responseText; // Response data.
alert(o.responseText);
};
Y.on('io:complete', complete, Y);
var request = Y.io("http://maps.googleapis.com/maps/api/geocode/json?language=en&sensor=false&latlng=12,34);
});
//-->
</script>
I get a reply with method OPTIONS and status code 405 Method Not Allowed.
I believe this is because of some "preflight" permission check. I do not receive the desired response. If I copy and paste the url into the browser, I see the json data.
I could post the ajax request to a php script on my own domain and get the json response with curl.
But why have this extra step if I could just get the data in javascript?
So what can I do to solve this? Is the IO utility not the right library to use?
You're making a cross-domain XHR request, and running into the "Same origin policy", a generic restriction in client-side JavaScript. See for example Why do I still receive 405 errors even though both URLs are from XXXX.com?
There are various ways to work around this problem:
1) Make a server-side request in PHP, as you suggest
2) Use the YUI jsonp module
3) Use the YUI YQL module, which proxies your request through Yahoo! servers and handles JSONP housekeeping for you
There are many other ways to tackle this problem, but those three should get you started.
Y.io has support for cross domain requests. See http://yuilibrary.com/yui/docs/io/#cross-domain-transactions
You need to properly config it with the "xdr" property, and load the "io-xdr" module, etc. This example uses it as well: http://yuilibrary.com/yui/docs/io/weather.html
I need to post some json data to external(another domain) API using ajax which on success should return me back some json data.
This API doesn't supports GET, only POST and I have no control on it, which means I can't do JSONP or enable CORS.
Any idea how to bypass the cross-domain limitations?
Post the data to your own server. Make the HTTP request to the API from your server. Relay the response.
You have to use a proxy page: you'll send the ajax post to the proxy page, which must reside on the same domain, and the proxy page will take care of posting the data to the final destination.
A php example: http://jquery-howto.blogspot.it/2009/04/cross-domain-ajax-querying-with-jquery.html
A Java example: http://snipplr.com/view/17987/