117 lines
2.7 KiB
Markdown
117 lines
2.7 KiB
Markdown
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---
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title: PHP Cookies
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---
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# PHP COOKIES
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## What is a Cookie?
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A cookie is often used to identify a user. It is a small file that the server embeds on the user's computer.
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Each time the same computer requests a page with a browser, it will send the cookie too.
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Cookies were designed to be a reliable mechanism to remember stateful information or to record the user's browsing activity.
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They can also be used to remember arbitrary pieces of information that the user previously entered into form fields such as names, addresses, passwords, etc.
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## Creating Cookies with PHP
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With PHP, you can both create and retrieve cookie values.
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A cookie is created with the setcookie() function.
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`setcookie(name, value, expire, path, domain, secure, httponly);`
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Only the _name_ parameter is a required parameter. All other parameters are optional.
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## PHP Create/Retrieve a Cookie
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The following example creates a cookie named "user" with the value "John Doe".
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The cookie will expire after 30 days (86400 * 30).
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The "/" means that the cookie is available in entire website (else, you can select the directory you prefer).
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We then retrieve the value of the cookie "user" (using the global variable $_COOKIE).
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We also use the isset() function to find out if the cookie is set:
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**Example:**
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```
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<?php
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$cookie_name = "user";
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$cookie_value = "John Doe";
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setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/"); // 86400 = 1 day
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?>
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<html>
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<body>
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<?php
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if(!isset($_COOKIE[$cookie_name])) {
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echo "Cookie named '" . $cookie_name . "' is not set!";
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} else {
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echo "Cookie '" . $cookie_name . "' is set!<br>";
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echo "Value is: " . $_COOKIE[$cookie_name];
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}
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?>
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</body>
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</html>
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```
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**Note:** The setcookie() function must appear **BEFORE** the <html> tag.
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Output:
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Cookie 'user' is set!
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Value is: John Doe
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## PHP Modify a Cookie Value
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To modify a cookie, just set the value again using the setcookie() function:
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**Example:**
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```
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<?php
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$cookie_name = "user";
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$cookie_value = "Jane Porter";
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setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/");
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?>
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<html>
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<body>
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<?php
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if(!isset($_COOKIE[$cookie_name])) {
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echo "Cookie named '" . $cookie_name . "' is not set!";
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} else {
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echo "Cookie '" . $cookie_name . "' is set!<br>";
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echo "Value is: " . $_COOKIE[$cookie_name];
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}
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?>
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</body>
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</html>
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```
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Output:
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Cookie 'user' is set!
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Value is: Alex Porter
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## PHP Delete a Cookie
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To delete a cookie, use the setcookie() function with an expiration date in the past:
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**Example:**
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```
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<?php
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// set the expiration date to one hour ago
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setcookie("user", "", time() - 3600);
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?>
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<html>
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<body>
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<?php
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echo "Cookie 'user' is deleted.";
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?>
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</body>
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</html>
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```
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Output:
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Cookie 'user' is deleted.
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