I fear I may be trying to do something that certain security policies are specifically designed to forbid.
So there's a certain site with a certain AJAX-based chat application. It periodically polls the server and receives HTML fragments in return. I am looking to write an alternate mobile frontend that directly queries the existing backend using JS (i.e. does not use my server as a reflector).
Two main issues here that make this different from most such questions:
The server owner wouldn't mind me doing this but he's not going to go out of his way to help me, and so the format for talking with the server is not something I can change. That is, the server doesn't talk JSON let alone JSONP. It's HTML fragments but for my purposes that's essentially text.
I need to have the return value available to parse manually. It should not be automatically parsed/inserted/what-have-you through inclusion in the DOM or some other such mechanism.
If anyone has some advice on this matter, I would really appreciate it.
You could use a server side script to proxy it through your server.
You could use YQL as the middle man and use JSONP or CORS.
Tell the person on the other server to set up CORS for your server (tell them to add a header for each request, e.g. Access-Control-Allow-Origin: example.com).
could you create a php proxy,
ajax send url to fetch to local php(or other serverside script)
php uses curl to fetch that page and returns result.
Related
I taught myself programming so my knowledge is very fragmented and now I have encountered a fragment I know nothing about. Sending and receiving Date. In addition I want to do it across domains. I know about the security policies that prohibit this but have read about some solutions. I still can't make sense of it in relation to my challenge.
What I want to do:
I want to build a plugin that sends data to my server when a function is called. The function is bound to an event listener.
this plugin contains of a little html-form and some js in the back. i want to send json or simular.
my questions:
I) how do I send data to an other server?
II) how do I receive this data? I know about parsing and dom but all I did so far is handle requested data. now this data is posted to my server-app without me knowing beforehand. the data is used to update a DB. the backend is coded in JS or python. I would prefer JS for compatability reasons.
III) how can I test the cross server connection on my local machine? especially without an active internet-connection?
I don't expect a complete guide or the code i need. just the resources and where to get the knowledge-chunks I need to build this.
Thanks a bunch in advance!
I) how do i send data to an other server?
You may use AJAX (or jQuery.ajax a more convenient way)
II) how do i receive this data? i know about parsing and dom but all i
did so far is handel requested data. now this data is posted to my
server-app without me knowing beforehand. the data is used to update a
DB. the backend is coded in JS or python. i would prefer JS for
compatability reasons.
As long as you send some data via AJAX, the browser makes a HTTP call and you could receive the data from server-side. Both JS or python would compatible with your client-side javascript and seldom do there have compatibility issue.
III) how can i test the cross server connection on my local maschine?
especially without an active internet-connection?
localhost and 127.0.0.1 is treated as different host and I usually use these to test cross server scenario. One issue of AJAX is that browser usually disallow Cross Domain calls unless you specify Access-Control-Allow-Origin headers.
Is there a way to send data packets from an active Python script to a webpage currently running JavaScript?
The specific usage I'm looking for is to give the ability for the webpage, using JavaScript, to tell the Python script information about the current state of the webpage, then for the Python script to interpret that data and then send data back to the webpage, which the JavaScript then uses to decide which function to execute.
This is for a video game bot (legally), so it would need to happen in real time. I'm fairly proficient in Python and web requests, but I'm just getting into JavaScript, so hopefully a solution for this wouldn't be too complex in terms of Javascript.
EDIT: One way I was thinking to accomplish this would be to have Javascript write to a file that the Python script could also read and write to, but a quick google search says that JavaScript is very limited in terms of file I/O. Would there be a way to accomplish this?
For security reasons, javascript in a browser is usually restricted to only communicate with the site it was loaded from.
Given that, that's an AJAX call, a very standard thing to do.
You can make HTTP requests using the XMLHttpRequest API, which Jquery abstracts with $.ajax and $.get. You can also use the lower level Websockets network API:
https://developer.mozilla.org/en-US/docs/WebSockets
Note that the XMLHttpRequest API will only allow requests to the same server, OR requests that return an appropriate Access-Control-Allow-Origin header.
It sounds like the Javascript is only going to send information, not receive any. In that case, you're in luck. I'm guessing you are also running the Javascript and the Python on the same machine.
Run a Python webserver on the machine the browser is running on. Here's a simple example:
http://webpy.org/install
Once visiting http://127.0.0.1:8080/ in your browser gives the message Hello World!, you can start adding more addresses to your website, for example http://127.0.0.1:8080/report_data, http://127.0.0.1:8080/report_event etc.
Your Javascript can then make AJAX requests using jQuery.ajax or XMLHTTPRequest, to the address http://127.0.0.1:8080/report_data, and pass the information as GET parameters.
I have a web-page which content must be constructed on the fly. When user clicks some parts of the web-page, it must load information from the file which is placed on the server in the same directory along with web-page into special content <div>.
As far as I get it, with JavaScript, I must use ajax technology so I have a question: should I configure server so that he can handle ajax requests specifically, or is it just simple GET over HTTP request which should be supported by any web-server anyway?
And my second question - if ajax is technology, which will work out only if server is properly configurated, can I do what I need by simple GET from JavaScript somehow?
Also, if it is easier to use server-side scripting, how can it be done by VBScript?
AJAX requests are very much like usual HTTP requests. So you do not need to configure your server in any special way to make them work.
A usual server should already support at least GET and POST requests.
One thing, that might be important for you, however, is, that as long as there is no other "protection" for the files, everyone can access them directly, too. So in case the AJAX-loaded content contains some kind of user sensitive data, you should put some access control in place!
AJAX involves server side scripting, so it doesn't make sense to say it is easier to use server side scripting. Additionally, AJAX is nothing more than GET or POST requests that a script carries out for you asynchronously, allowing you to use the server responses in a document without reloading the entire page.
AJAX in and of itself is not so much of a technology as a technique. You can use AJAX, for example, without ever using the ubiquitous XmlHttpRequest object supplied by javascript.
With the jQuery AJAX methods, you can request text, HTML, XML, or JSON from a remote server using both HTTP Get and HTTP Post - And you can load the external data directly into the selected HTML elements of your web page...
and yes, no configa server properly
i suggest to you jquery framework (no server configure needed) (see also Sirko answer)
http://api.jquery.com/jQuery.ajax/
this is help you to load dynamic content see this
I want to have a dynamic webpage that automaticly updates some information, this information should be received from my c/c++ application using HTTP. I have set up a socket and can send HTML and Javascript files to the browser.
I don't know how to move on. How to encapsulate my data into XMLHttpRequest objects? Or maybe this isn't the way to go? The problem is that my c/c++ application will be run on an embedded system that can't really support php or something like that.
I can't really understand how XMLHttpRequest works, I only find a lot of client examples on the web and not much about how a server should handle it.
A server should handle it as any other request. From the servers point of view, it's a normal HTTP request. Return the data that the client asks for! This is usually a HTML fragment, some XML or some JSON.
Ajax just send normal HTTP GET POST ... request, you should make sure your response header is correct, such as Content-Type.
How do you send information to the browser? The browser is client-side. To get information, you must either query the server (which you say is written in C++). If you want your client to receive request, you should probably emulate a server-like behavior using NodeJS.
Let's say I want to use this API: http://hiveminder.com/help/reference/API.html
The instructions walk through its use via. the curl command line tool, which I'm unfamiliar with. I want to access this API through a simple script on my own page. What are the steps I need to do this?
Keep in mind it's been years since I've done any of this.
Because cross-site requests can't be done from the client, they need to be initiated from the server. I'm personally not familiar with Hiveminder, but the way in which you achieve requests from one domain to another is generally:
On the client-side, grab any necessary information from the user and send it to your server
From the server-side, initiate a request to the next domain (in your case, Hiveminder)
When the result is returned from said domain, send that information back up to the client.
I don't know what language your using, but since you mentioned cURL you may be interested in checking out what PHP offers in its cURL manual.