Cookies provide a convenient way to store session specific information client side.

The information stored in cookies varies and often covers user names, encrypted passwords or shopping trolley content.

Cookies are widely used, and their management is largely down to the configuration of a user's web browser and cookie clean-up policy. The user can enable and disable the support for cookies and remove stored cookies from their machine at any time.

As we discussed in the Introduction, the user can control if cookies are supported and when cookies are to be removed from their system. As a webmaster, this is not a means on which to rely when considering the time a cookie should be available.

Cookies can be configured to have a lifespan that is set when the cookie is created by the web page. The following examples demonstrate the creation of two cookies, called "yearcookie" and "sessioncookie":

<?lc
// Cookie lasts 1 year
put cookie "yearcookie" for "/" with "This cookie will stay on your system for a year" until (the seconds + 60 * 60 * 24 * 365)
// Cookie lasts until browser closes
// The default expiry time of a cookie is set to when the user's browser closes.
put cookie "sessioncookie" for "/" with "This cookie will be cleared when you close your browser closes"
?>

Cookies can be read from the user's computer using the $_COOKIE keyword. The following code prints the contents of the cookies that were created in the previous examples to the screen:

<?lc
// Output cookies
put "PRINTING COOKIES:" & "<br /><br />"
put $_COOKIE into tCookiesArray
if tCookiesArray is an array then
	printArray "$_COOKIE", tCookiesArray
else
	put "no cookies found"
end if
put "<br /><br />" & "FINISHED"
?> 

The code shown so far provides the basic mechanism to save and read cookie content. The array printing command that formats the output of the cookie content is provided here. This code is provided separately in this lesson, as it only serves to present the content in a readable form for this lesson. Normally you would write LiveCode commands to process the cookie content and extract the login information, shopping cart data or other content stored.

<?lc
// Commands to display an array in readable form
command printArray pArrayName, pArray
	if pArray is an array then
		put pArrayname & " = {" & "<br />"
		dumpArray pArray, " ", " "
		put "}"
	end if
end printArray
command dumpArray pArray, pIndent, pIndentString
	local tKeys
	if pArray is an array then
		put the keys of pArray into tKeys
		sort lines of tKeys
		repeat for each line tKey in tKeys
		if pArray[tKey] is an array then
			put pIndent & tKey & " = {" & "<br />" & return
			dumpArray pArray[tKey], (pIndent & pIndentString), pIndentString
			put pIndent & "}" & "<br />" & return
		else
			put pIndent & tKey & " = " & pArray[tKey] & "<br />" & return
			end if
		end repeat
	end if
end dumpArray
?>

The first time you run the code listed in this lesson, you may get the following output:

PRINTING COOKIES:

no cookies found

FINISHED

This may be because the printing code is executed before you have saved the cookies or because of a latency that exists when writing a cookie to a file system.

If no cookie data is displayed, then refresh your web browser screen. You should then receive the output that is shown in the next step.

If your code was successful, then you should see the following output in your web browser window:

PRINTING COOKIES:

$_COOKIE = {

sessioncookie = This cookie will be cleared when you close your browser closes

yearcookie = This cookie will stay on your system for a year

}

FINISHED

Both cookie examples are listed and the content of the two cookies is also displayed.