How to make a system which retrieves links and replaces the url with the relevant title name of that page?

Question

Recently I saw that when I put the link in my profile it replaced it with the exact title of the question. So I want to know, how do they do it?

I am guessing that they do this by sending the link via ajax and then make a link header by php implode ,explode. Is this correct way/same way that Stack Overflow does this?

+1: this is a very valid programming question IMHO? He could have asked, I would like to convert the link I paste into my textbox as the page title. — naveen, Sep 16 '12 at 05:45
1 close vote for off topic ?? and 3 for not a real question ?? — NullPoiиteя, Sep 16 '12 at 05:50

score 5 · Accepted Answer · answered Sep 16 '12 at 05:54

Suppose I am pasting the above link in the textarea like this

http://stackoverflow.com/questions/12444652/how-to-make-a-link-system-link-stackoverw

This is what happens behind the scenes. A GET request is made to the below URL

http://api.stackexchange.com/2.0/questions/12444652?pagesize=30&key=6AU78DZ)GcdjNjAszYmTLQ((&filter=!6G7RPxWUNTleV&site=stackoverflow.com&callback=apiCallbacks[%22stackoverflow.com%22]&_=1347774461814

The response of that GET is

apiCallbacks["stackoverflow.com"]({"items":[{"question_id":12444652,"title":"How to make a link system link stackoverw"}]});

From that one could retrieve the title. Hope this helps.

+1 ,yes this is exactly what is happening – NullPoiиteя Sep 16 '12 at 05:58 — NullPoiиteя, Sep 16 '12 at 05:58

score 4 · Answer 2 · edited May 23 '17 at 10:25

4

I thought this was too much info to put in a comment, so I just put it as an answer. The program just simply retrieves the value of the title element on that page.

So this is the basic process:

The program does a regex (or whatever) search for a url in the string.
The program obtains that url.
The program replaces the url with the relevant html code: ('foo', etc.)

UPDATE: This is how one would do the 3rd step with php:

$myURL = 'http://www.google.com';
preg_match('/<title>(.+)<\/title>/',file_get_contents($myURL),$matches);
$title = $matches[1];

(from here)

edited May 23 '17 at 10:25

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answered Sep 16 '12 at 05:41

Lucas

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+1 for better approach by suggesting the regx and to know what is exactly going on see the naveen answer – NullPoiиteя Sep 16 '12 at 06:03

How to make a system which retrieves links and replaces the url with the relevant title name of that page?

2 Answers2