Switchee adds a powerful switch/case control structure to ExpressionEngine templates, and can be used as an alternative to if/else conditionals.

Prior to EE.2.9.x, if/else "advanced conditionals" were parsed at the very end of the parsing process, with the result that tags within non-matching conditons were still parsed unecessarily before being removed.

With the release of EE 2.9.0, if/else conditionals can now evaluate regular expressions and are parsed "when ready" - when the variable being evaluated has a known value. In most cases this solves the main problem that Switchee was designed to solve, however there are some occassions where this can still result in non-matching conditions being parsed. Unlike if/else, Switchee is parsed linearly with other tags - immediately after preceding tags but before any following tags on a given layer of the template - so you can rely on it to always remove non-matching conditions before they can be parsed.

Switchee has the following advantages over if/else:

• Parsed linearly
• Evaluate global, GET, POST and Stash variables
• Optionally, all matching cases can be returned with match="all"
• Fast and stable with very large strings without hitting PCRE memory / recursion issues (tested with millions of lines)

If/else has the following advantages over Switchee:

• Native, first-party functionality
• Comparison, logical and mathematical operators
• String concatenation
• Error handling

So which should you use today?

For general presentation logic if/else is less verbose and the operators make it the more flexible choice.

When working with dynamic variables such as those created by Stash or passed in the POST array, Switchee is the obvious choice.

Need to output an entirely different page for a particular segment value? I strongly recommend you use Resource Router or the native template routes functionality instead of complicating your templates with routing logic.

Unzip the download and rename the extracted directory to 'switchee'.

Move the 'switchee' folder to the ./system/expressionengine/third_party directory.

Move the 'switchee' folder to the ./system/user/addons directory.

{exp:switchee variable="{variable_to_test}" parse="inward"}
	
	{case value="value1|value2"}
		Content to show
	{/case}
	
	{case value="value3" default="yes"}
		Content to show
	{/case}
	
	{case value="#^P(\d+)$#|''"}
		Use regular expressions enclosed by hashes #regex#
		Be careful to encode the following reserved characters as follows:
		{ = {
		| = |
		} = }
		Use '' to represent an empty string
	{/case}
	
	{case value="value4" default="yes"}	
		
		{!-- you can also nest Switchee by leaving off the 'exp:' in nested tags : --}
		{switchee variable="{another_variable_to_test}" parse="inward"}
			{case value="value1"}
				nested content to show
			{/case}
		{/switchee}	
		
	{/case}
	
{/exp:switchee}

{if switchee_no_results}
	{redirect="channel/noresult"}
{/if}

{!-- Output: 'Orange O' --}	
{exp:switchee variable="orange" match="all" parse="inward"}
	
	{case value="orange"}
		Orange
	{/case}
	
	{case value="#^o#"}
		O
	{/case}
	
	{case value="apple"}
		Apple
	{/case}
	
{/exp:switchee}

GET and POST globals can be evaluated by prefixing with get: or post:, e.g.:

{exp:switchee variable = "post:my_var" parse="inward"}

Global variable can be evaluated by prefixing with global:, e.g.:

{exp:switchee variable = "global:my_var" parse="inward"}

Stash variables can be evaluated by prefixing with stash:, e.g.:

{exp:switchee variable = "stash:my_var" parse="inward"}