Php,js,ajax What kind of technology can be used to change foreground data in the background

Php,js,ajax which technology can change foreground data in the background?
Cases:
Front page login.php:
A login form, account and password Plus submit button
At this time, fill in the Account password click button, how to let the page into the waiting state? And then
How can the background admin.php, view the form of the user submitted by this foreground, and then send a message to the page that the user is visiting? or change the code or data or links on his current page?


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Background change front desk is basically not feasible, although said now have websocket this new protocol of full duplex. Your need for this is basically AJAX-enabled.

The basic logic is to click the Submit button, with the JS control to display the waiting page, when the server has a return value, cancel the display of the waiting page, in accordance with the return value with JS to modify the current page display.
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This demand sounds weird, but I know you must be Ajax.
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My general practice is: Do not use form submission. The Submit button is tied to a point-and-click event via JavaScript, and the handler for the event pops up a wait box (a div that loads the animation and obscures the entire page), sending post data (user name, password) to PHP via Ajax and binding the callback function. When PHP finishes processing the results back to the page, the callback function that is bound by Ajax hides the wait box and changes the display of the page based on the results returned by PHP (or jumps to other pages or prompts for errors, etc.).
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Ajax technology can solve the landlord problem.

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