Редирект страницы php. Как в PHP задать редирект на другой URL до загрузки страницы

Last modified on February 25th, 2017 by Vincy.

PHP redirect mechanism is used to navigate the user from one page to another without clicking any hyperlinks. This will be helpful in such circumstances where the redirect should be done in the background. For example, when the user is accessing payment gateway, the redirect should automatically be taken place to notify URL using PHP script.

PHP provides predefined function, named header(),for URL redirection. Using this header() function, we need to send location header by specifying URL to which the page should be redirected.

Unlike where there are several ways to handle URL redirect works based on the browser, PHP avoids such confusion and have header() function create the same effect in all browsers. For that only, we have concluded with JavaScript redirect article that server side redirect is preferable.

In the above syntax of PHP redirect, we need to replace with a valid URL to which we want to move. We can specify either absolute URL or relative URL for this location header. If we specify relative URL, it will search for the page in our domain where we exist.

Note: Before specifying page URL for location header, we should make sure that the page exists.

Before executing PHP redirect, we should ensure about, no output is sent to the browser before the line where we call the header() function. For example,

Echo "PHP Redirect"; header("Location: сайт");

This script will display the following warning notice to the browser.

Warning: Cannot modify header information - headers already sent by (...

It is not only applicable for header function, rather for all the PHP functions like set_cookie(), session_start() and etc., whatever can modify the header. For that, we should remove all content which will stop sending location header to the browser.

• HTML content like text or tags.
• Unnecessary white spaces before PHP delimiters.
• PHP error or warning notices that occur before calling redirect.
• PHP , like, echo(), print().

• Since HTML content should be sent before the redirect, we can separate PHP logic from HTML content.
• For being in the safety side we can put exit command after redirect statement of PHP file. For example, header("Location: сайт"); exit;
• We can enable PHP output buffering to stop sending output to the browser and stored into a buffer instead.

(PHP 4, PHP 5, PHP 7)

header — Send a raw HTTP header

header (string $header [, bool $replace = TRUE [, int $http_response_code ]]) : void

header() is used to send a raw HTTP header. See the » HTTP/1.1 specification for more information on HTTP headers.

Remember that header() must be called before any actual output is sent, either by normal HTML tags, blank lines in a file, or from PHP. It is a very common error to read code with include , or require , functions, or another file access function, and have spaces or empty lines that are output before header() is called. The same problem exists when using a single PHP/HTML file.

The header string.

There are two special-case header calls. The first is a header that starts with the string "HTTP/ " (case is not significant), which will be used to figure out the HTTP status code to send. For example, if you have configured Apache to use a PHP script to handle requests for missing files (using the ErrorDocument directive), you may want to make sure that your script generates the proper status code.

The second special case is the "Location:" header. Not only does it send this header back to the browser, but it also returns a REDIRECT (302) status code to the browser unless the 201 or a 3xx status code has already been set.

Replace

The optional replace parameter indicates whether the header should replace a previous similar header, or add a second header of the same type. By default it will replace, but if you pass in FALSE as the second argument you can force multiple headers of the same type. For example:

Http_response_code

Forces the HTTP response code to the specified value. Note that this parameter only has an effect if the header is not empty.

No value is returned.

Example #1 Download dialog

If you want the user to be prompted to save the data you are sending, such as a generated PDF file, you can use the » Content-Disposition header to supply a recommended filename and force the browser to display the save dialog.