So I'm writing a post on my wall and type a URL into the main body of the post. As soon as I finish the URL, Facebook creates a little section underneath which has the title, description, and an image from the url I typed.
Without getting too indepth, how is this done and what is the best way of make something similar myself?
jQuery (or some other framework that lets you do Ajax easily) to communicate between browser client and webserver
PHP/ASP.NET/Python (or some other scripting framework on the backend) to fetch the url
Facebook also has a meta data specification you might be interested in, to let developers further define what gets shown in a Facebook page.
I believe Facebook is written in PHP. And PHP does this easily.
FOpen can be used to access files on other sites. There are other functions but this will get you started. Then it's a matter of parsing the html you get from the url to get what you want.
http://php.net/manual/en/function.fopen.php
You have a couple choices. You can fetch it using Ajax from the client; or you can fetch it from your server.
If doing it from your server in asp.net then you need to use HttpWebRequest.
FB does an asynchronous JavaScript call to fetch that data without reloading the window you're on. Lookup ajax and libraries like jquery do this: http://api.jquery.com/category/ajax/
Related
I am trying to make a mobile application for an online gradebook called netclassroom. I was not able to use the API that they offer, so I was wondering if it would be possible to open a webview on the side and get data once user credentials are inputted. Would that be considered inefficient? Or is scraping html not the best way to get data compared to using an API?
Any help would be appreciated.
maybe you can make a web request (POST/GET) to the same URL instead and read the response as XML
I'm writing a toy application to get acquainted with AngularJS. This application has a Rails backend.
I don't know how to make the client side angularjs app, deal with a PDF that the backend sends when hitting a particular URL (http://localhost:3000/contacts.pdf)
When typing the above mentioned URL straight in the browser, the server replies with a PDF and the browser asks what to do with it (download or open).
When the same thing is done via the angularjs app, I can see the file gets returned in the response. And that's where I'm stuck at.
How can I replicate the same behaviour within client side app?
Thanks for your help
One way is just use an anchor tag in HTML and put the link as a controller variable ie. Download and in controller put $scope.link = "http://localhost..."; (or array if requiring multiple links).
If this is not what you want, please add further clarification.
I have two sites, my main site and a help site with documentation. The main site is rails but the other is simple a wordpress like blog. Currently I have it being pulled into the main site with an iframe, but is there a good way to pull in the html from the other site as some sort of cross-domain (sub-domain actually) partial? Or should I just stick with what works?
If the data sources were all on the same domain, you would be able to utilize straight AJAX to fetch your supplemental content and graft it onto your page. But, since the data is from different domains, the same origin security policy built into web browsers will prevent that from working.
A popular work around is called JSONP, which will let you fetch the data from any cooperating server. Your implementation might look something like this (using jQuery):
$.getJSON(
"http://my.website.com/pageX?callback=?",
function(data) {
$("#help").append(data)
}
)
The only hitch is that the data returned by your server must be wrapped as a javascript function call. For example, if your data was:
<h1>Topic Foo</h1>
Then your server must respond to the JSONP request like this:
callbackFunction("<h1>Topic Foo</h1>")
Trying to figure out a way where I can pass some data/fields from a web page back into my application. This needs to works on Windows/Linux/Mac so I can't use a DLL or ActiveX. Any ideas?
Here's the flow:
1. Application gathers some data and then sends it to a web page using POST that is either imbedded in the app or pops up a new IE window.
2. The web page does some services and then needs to relay the results back to the application.
The only way to do this that I can think of is writing the results locally from the page in a cookie or something like that and have the application monitor for a specific file in that folder.
Alternatively, make a web service that the application hits after passing control to the page and when the page is done the web service will return the data. This sounds like it might have some performance drawbacks.
Can anyone suggest any better solutions for this?
Thanks
My suggestion:
Break the processing logic out of the Web Page into a seperate assembly. You can then create a Web Service that handles all of the processing without needing to pass control over to a page.
Your application can then call the Web Service directly and then serialize the results and work with the data quite easily.
Update
Since the page is supplied by a third party, you obviously can't break anything out. The next best thing would be to handle the entire web request internal to your application (rather than popping a new Window).
With this method, you can get the raw HTTP response (and page markup) and work with it directly. You can then parse the Response stream and gather the required data from it.
During performing an HTTP request you should be able to retrieve the text returned by the page. For instance, if your HTTP POST was to hit a Java servlet, the doPost() method would be fired and you would then perform your actions, you could then use the PrintWriter object from the Response object (PrintWriter out = response.getWriter();) and write text back to the calling application. I'm not sure this helps?
The fact that
web page is hosted by a third party
and they need to be doing the
processing on their servers.
is important to this question.
I like your idea of having the app call a webservice after it passes the data to the third-paty web page. You can always call the webservice asynchronously if you're worried about blocking your application while waiting for results from this webservice.
Another option is that your application implements an XML-RPC server that can be called from the web page using PHP, Python or whatever you use to build the website
A REST server will do the job also...
is it possible to submit forms with yahoo pipes?
i basically need to log in somewhere, and get some stuff from the members area of a website into a feed.
Although this is not exactly programming related... I guess it is close enough.
No, logging into somewhere is impossible with Yahoo Pipes. Sending the username/password isn't even the only problem here.
The real problem is that most, if not all, web sites that require a log-in depend on a session cookie or something similar. Yahoo pipes can do a GET request, and that's about it. Even if it was possible to send your user name/password in the URL, you would not be able to use the session cookie, so subsequent requests would fail.
So... If you have access to a hosted web site somewhere: Write a small proxy script (in PHP or whatever is available) that does the login and fetches the data. Let Yahoo pipes read from your proxy page. But if you are that far, you can just as well produce RSS format right away. ;-)
I did a pipe that can log in and extract info. is working ok on a simple web form using POST.