Post/Redirect/Get

From Wikipedia, the free encyclopedia

It has been suggested that this article or section be merged into Representational State Transfer. (Discuss)

An editor has expressed a concern that the subject of the article does not satisfy the notability guideline or one of the following guidelines for inclusion on Wikipedia: Biographies, Books, Companies, Fiction, Music, Neologisms, Numbers, Web content, or several proposals for new guidelines.

If you are familiar with the subject matter, please expand the article to establish its notability. The best way to address this concern is to reference published, third-party sources about the subject. If notability cannot be established, the article is more likely to be considered for deletion, per Wikipedia:Guide to deletion. (See also Wikipedia:Notability)
This article has been tagged since November 2006.

Post/Redirect/Get (PRG) is a common design pattern for web applications, to help avoid duplicate form submissions and allow applications to behave more intuitively with browser bookmarks and the reload button.

After a web user submits a form to a server, the server typically generates an HTML page as a response. To the user, this looks like an ordinary web page, but because it was generated by an HTTP POST request, it cannot be bookmarked, and attempting to reload/refresh the page in the browser could cause the form information to be resubmitted, possibly with unexpected results (such as a duplicate purchase).

To avoid this problem, many web applications use the PRG pattern — instead of returning an HTML page directly, the POST operation returns a redirection command (using the HTTP 303 response code (sometimes 302) together with the HTTP "Location" response header), instructing the browser to load a different page using an HTTP GET request. The result page can then safely be bookmarked or reloaded without unexpected side effects.