GOOCODE - Find your code/scripts

5 We submit the form, a limit can not be ignored is to prevent users who repeatedly submit the form, because there may be a user continuously hits the submit button or a malicious attacker to submit the data, then we submit the data after processing, such as modifying or adding data to the database when they will get into trouble.

So how do you avoid duplicate submission form this phenomenon happen? We can see from many aspects, first from the front end to make restrictions. In the front-end javascript is disabled after a button is clicked, the disabled, this simple method of preventing multiple clicks the submit button, but the disadvantage is that if the user has disabled javascript script is invalid. Second, we can do after submitting the redirect page redirection, that is submitted after the jump to a new page, the main F5 avoid duplicate submissions, but there are drawbacks. Thirdly, it is made unique database index constraint. Fourth, it is to do the session token authentication.

50 When we submit the form, sometimes you encounter the need to repeat the same form to add multiple elements, such as order information you need to add a number of different types of products, form data in the new field information. This time we can put a "new one" or "Copy" button directly on the form, you can achieve copy form elements by clicking on the button.

2 jQuery Form plug-in is an excellent Ajax form plugin, we can very easily use it to value processing form controls, clear and reset form controls, attachment uploads, and the completion of Ajax form submission. jQuery Form has two core methods ajaxForm () and ajaxSubmit (), in this article we focus on ajaxSubmit () applications.