PHP script installation progress steps?

Some scripts don't have javascript to refresh the page itself but when they are performing step by step installation, they can auto push new texts / steps / instruct开发者_如何转开发ions to the web page.

How do they do this?

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It's not entirely clear to me from your question what you mean (or pretty broad), this depends on how this was done, so a concrete example would be useful.

Anyway, normally this is done by creating an installer session and then submitting forms to a controller which will handle the input and decide upon the input and the current session's state what to display next.