https://www.goodreads.com/api/index contains an example how to call json api by js
<script type="text/javascript">
function myCallback(result) {
alert('nb of reviews for book: ' + result.reviews.length);
}
var scriptTag = document.createElement('script');
scriptTag.src = "https://www.goodreads.com/book/isbn/0441172717?callback=myCallback&format=json&user_id=123456789";
document.getElementsByTagName('head')[0].appendChild(scriptTag);
</script>
To be frank, it is so strange to me that url could contains a callback function name. What's the secret here? Any relevant js document?
Anyway, it is a javascript example. If I want to use python requests to do the same job. How and what should I do?
I am completely stuck here.
Thanks for your advice.
This type of call is really only used from the browser, so it wouldn't apply to a Python request.
This is an example of a JSONP request, which is a way to make a cross-origin request, EG, your app served at foobar.com wants to make a POST request to example.com. In many (but not all) circumstances such requests will be blocked by your browser for security reasons.
In this case, the result of the request is passed to the callback, which is then executed by the browser.
Related questions have been asked before, there's a nice explanation of JSONP-- how it works, and why you would want use it here: https://stackoverflow.com/a/2067584/3084820
If you are using requests you won't have the cross-origin concern, since you'll be making that request from the server side. I am not familiar with the goodreads API but I suspect that they have a version of the endpoint that can be called from a server.
NOTE: The Goodreads API is fairly weird and not well-documented. I played around with this and was able to get it to work using requests, but EG you need to send your API key as key=... not user_id=...
Related
Ok here's my problem. I'm working on this little site called 10winstreak and I'm trying to detect if a stream is live or not with javascript because our server that we run the site off of cant handle processing every single request with PHP. The basis of detecting if a stream is live or not is you go to their XML file and in one of their tags (if it's live) it will say something along the lines of true and often time the XML file on their site will be empty if a particular stream isn't live. for example if you have a twitch.tv stream for gamespot you go to http://api.justin.tv/api/stream/list.xml?channel=gamespot and if it's got stuff in it then it's live if not then it's not.
so basically my code looks like this:
function check (URL, term){
$.get(URL , function(data){
console.log(data);
//data is whatever the server returns from the request, do whatever is needed with it to show who is live.
var number = data.search(term);
if (number > -1)
{
document.write("Live");
}
else
{
document.write("Offline");
}
});
}
and URL is a url that gets passed in and term is the term to search for in the xml file (usually "true" or "True"). but before anything happens I end up with "XMLHttpRequest cannot load http://api.own3d.tv/liveCheck.php?live_id=6815. Origin (my server's URL) is not allowed by Access-Control-Allow-Origin."
I've looked into it all over the net and i dont seem to be able to find anything that I can use. there's alot of theory stuff but not enough actual code and i dont understand the theory stuff to be able to start typing code out. from what i've seen you have 2 ways to go, use JSONP or add a line somewhere in your sever to allow for cross-domain accessing. neither of which i understand fully nor know how or what to do. It would be alot of help for someone to show me what needs to be done to get rid of this error. of course if you can explain it to a non-coder like me it would be even more awesome but at my current point, as long as the code works for all I care it might as well be magic lol.
You can solve it :)
Take a look at xReader
<script src="http://kincrew.github.com/xReader/xReader.full.js"></script>
<script type="text/javascript">
xReader("http://api.own3d.tv/liveCheck.php?live_id=6815", function(data) {
alert(data.content);
})
</script>
I think you need cacheburst option. but you can be banned from YQL.
I think its because the path is not relative. You may be calling this from a different domain/sub-domain. You can potentially allow other origins to access, which may open up a security hole or you can create a proxy locally.
In PHP creating a proxy is easy: http://blog.proxybonanza.com/programming/php-curl-with-proxy/
Now, instead of directing your request straight to that URL send the request from jQuery to your own local url and have it access it on the server side.
Another option would be to use YQL: http://www.parrisstudios.com/?p=333 (I wrote an article about this a while ago)... In that way you can turn the response into JSON, which can be accessed cross-domain (as can javascript).
You could ask for the API responses to all be returned using a JSONP server and in JSON.
You aren't going to be able to do this via client-side javascript unless they've enabled some way to retrieve their data cross-domain (CORS, JSONP, some flash widgety thing getting read permissions from crossdomain.xml file(s) located on their server...)
Short answer: unless 10winstreak offers a JSONP service, you'll have to do things on the server-side.
Slightly longer answer:
For security reasons browsers won't let you make AJAX requests from www.example.com to www.example2.com (or any other domain except www.example.com). There isn't much you can do about this except use JSONP (and you can only do that if the remote webservice offers it).
Therefore, what you end up needing to do is ask your server "hey what's on that other server?" and (since it's not limited the way a browser is) it can go get the XML from that other server. There are various ways of doing this, either with code or Apache config; not sure what's right for you, but hopefully now you understand the general principle.
P.S. See this question: Wouldn't have been simpler to just discard cookies for cross-domain XHR? if you are curious why browsers do this.
* EDIT *
I just checked out JustinTV's site, and it appears that they already have a PHP library for you to use:
https://github.com/jtvapi/jtv_php_api
This is very likely your best bet (if you want to keep using PHP that is; if not they have libraries for other languages: http://www.justin.tv/p/api).
the url is input by end users as string on my page, so may point to any domains.
JavaScript in current page needs to sniff the url, verify whether it's still valid, and return the types as image, or video, or audio, even considering html5 video audio tag and existent flash embed. And No need to wait for the complete file transfer.
Can someone help, from concept? thanks very much.
i'm aware the cross domain problem on ajax. So no idea on basic how-to.
If what you're asking, is:
Given any URL -> lookup given URL using a javascript ajax request, and determine if it is a video/audio/image - then, once detected, use the URL accordingly, then you can do something like this:
jQuery and AJAX response header
However, you'll not be able to make a request using client-side JavaScript to another domain, as it will require a cross-domain request (where your alternatives are JsonP, or weird headers in the response).
You're better off passing the URL to your own server, and performing the logic there (Via some kind of server-side web request) and passing a payload back to the client, with the required information in JSON or something - e.g.
{payload: 'video'}
Old question, but I recently wrote a utility that might help you out. It's a CORS-enabled MIME-type checker. See the API doc at lecoq.herokuapp.com
Use it like so: example
i've got a little problem with AJAX, CouchDB and JavaScript.
I can open the following URL from CouchDB in my browser: http://192.168.1.58:5984/mydb/name
new Ajax.Request('http://192.168.1.58:5984/mydb/namee', {
method: 'POST',
onComplete: function(transport) {
alert(transport.responseText);
}
});
I always get empty alert.
Can you help me?
The problem here is, that your browser doesn't allow you to make a query on an other web server than the one where you're script originates. (Google for: Same Origin Policy)
But there is a kind of a common technique which is a workaround for this use case. It's called JSONP. Since version 1.0 you have to activate this functionality first in CouchDB. In the section [httpd] of your CouchDB configuration file (.ini) you have to add an
allow_jsonp = true
After this is done you can produce JSONP queries on your CouchDB. Basically adding dynamically lines like this:
<script type="text/javascript"
src="http://server2.example.com/getjson?callback=parseResponse">
</script>
But for details refer to the article linked above.
Anyway I propose on the JavaScript side of things to use a Framework as jQuery, DojoToolKit, ect. In jQuery e.g. it is enough to add "?callback=?" at the end of the URL.
AJAX doesn't support cross domain scripting. all calls need to be to a URL with the same domain as the one of the current document.
a good solution would be to build a proxy service on the server side, that will take the local
request, make an HTTP call to the couchDB server, and return it's response.
This is probably a very silly question. I am trying to do a geolocation to find a users address based on their ip address using the api provided by http://www.hostip.info/use.html. I am using this in conjuction with jquery with the following code:
$.get("http://api.hostip.info/get_html.php", function(data){
alert("Data Loaded: " + data);
});
Sadly, this doesn't seem to work. The alert is never triggered so i assume the call never returns. Has anyone done this before? Thanks
I don't think the call to them is successful. Cross-domain limitations are likely to prevent you from reading the result data. If hostip offered a JSONP API, that would be usable, but I didn't see any mention of one on their site.
If you use Google's AJAX API, then it's really easy to get location using their Client Location functionality -- this doesn't require any cross-domain calls.
if (google.loader.ClientLocation) {
var lat = google.loader.ClientLocation.latitude;
var lon = google.loader.ClientLocation.longitude;
...
Otherwise, as others have pointed out, you'll need a service that provides JSONP or you'll need to write a proxy on your own server to get the data for you.
You can't make cross-domain calls for XML data. Other sites offer a JSON interface:
http://ipinfodb.com/ip_query.php?ip=999.999.999.999&output=json
which you can cross-domain call using the YUI GET Utility or via JQuery.
You can't make calls to foreign domains from javascript. This is definitely the problem. You either need to set up a proxy script on your server that fetches remote pages for you, or find a service than implements JSONP as mentioned above.
Here's the problem:
1.) We have page here... www.blah.com/mypage.html
2.) That page requests a js file www.foo.com like this...
<script type="text/javascript" src="http://www.foo.com/jsfile.js" />
3.) "jsfile.js" uses Prototype to make an Ajax request back to www.foo.com.
4.) The ajax request calls www.foo.com/blah.html. The callback function gets the html response and throws it into a div.
This doesn't seem to work though, I guess it is XSS. Is that correct?
If so, how can I solve this problem? Is there any other way to get my html from www.foo.com to www.blah.com on the client without using an iframe?
It is XSS and it is forbidden. You should really not do things that way.
If you really need to, make your AJAX code call the local code (PHP, ASP, whatever) on blah.com and make it behave like client and fetch whatever you need from foo.com and return that back to the client. If you use PHP, you can do this with fopen('www.foo.com/blah.html', 'r') and then reading the contents as if it was a regular file.
Of course, allow_remote_url_fopen (or whatever it is called exactly) needs to be enabled in your php.ini.
There is a w3c proposal for allowing sites to specify other sites which are allowed to make cross site queries to them. (Wikipedia might want to allow all request for articles, say, but google mail wouldn't want to allow requests - since this might allow any website open when you are logged into google mail to read your mail).
This might be available at some point in the future.
As mentioned above JSONP is a way around this. However, the site that you are requesting the data from needs to support JSONP in order for you to use on the client. (JSONP essentially injects a script tag into the page, and provides a callback function that should be called with the results)
If the site you are making a request to does not support JSONP you will have to proxy the request on your server. As mentioned above you can do this on your own server or what I have done in the past is use a http://www.jsonpit.com, which will proxy the request for you.
One option is to implement a proxy page which takes the needed url as a parameter. e.g. http://blah.com/proxy?uri=http://foo.com/actualRequest
JSONP was partially designed to get around the problem you are having
http://ajaxian.com/archives/jsonp-json-with-padding
JQuery has it in their $.getJSON method
http://docs.jquery.com/Ajax/jQuery.getJSON
The method shown above could become a large security hole.
Suggest you verify the site name against a white list and build the actual URI being proxied on the server side.
For cross domain hits this is a good working example and now is considered as some what "standard" http://www.xml.com/pub/a/2005/12/21/json-dynamic-script-tag.html.
there are other ways as well, for eg injecting iframes with document.domain altered
http://fettig.net/weblog/2005/11/28/how-to-make-xmlhttprequest-connections-to-another-server-in-your-domain/
I still agre that the easy way is calling a proxy in same domain but then it's not truly client side WS call.