After googling and binging how to do this I found out that what I want to do is called scrapping and its not a good practice.
That really depends.

If it's a site that generates a hash or something for instance, and you want to retrieve the hash through a website rather than doing it directly from the program, then it's probably not a good thing. But in other cases, you have no choice but to get the data from the website because it doesn't exist anywhere else, so I don't see how you can call that bad practice. Especially if this is not your site, and you can't integrate some kind of JSON page or an SQL database that you can interact with depending on which way you want to do things.