How to parse a site according to certain criteria?

Question

PHP

Hello.
How to parse a site according to certain criteria?
For example, there is a site fl.ru, choosing the necessary fields, nothing is displayed in the get parameters.
And there are many such sites.
How to parse such sites if there are no get parameters?

Answer 1

For parsing, you need to:
a) get the desired page
b) extract the required data from it
c) do something with this data, for example, save it to the database.
And what does get fields have to do with it (and what is it in general)?
Take the link, download it to your file. In this file, extract the data, and do with it what you need.

Answer 2

Judging by the question, Ajax loading is used.
For example, open firebug in Mozilla, see where the requests went when you click on checkboxes or other elements on the site.
Take the received url addresses, and parse.