Conditional Tags¶

Introduction¶

Conditional Tags are pair tags, which allow you to conditionally show or hide information on your pages based on criteria being met. They take on this general form:

{if condition} data to show if condition is met {/if}

The syntax available for the condition is comparable to most programming languages. Some examples:

{!-- Basic truth tests --}
{if logged_in}Welcome back.{/if}

{!-- Comparisons --}
{if username == 'Bob'}Welcome back, Bob!{/if}

{!-- Math --}
{if (age + 5) == 100}Five years to go!{/if}

{!-- Logical operators --}
{if age == 30 and username == 'Bob'}Welcome back, Bob. 30 is the new 20.{/if}

{!-- Branching --}
{if age == 30}
  You are 30!
{if:elseif username == 'Bob'}
  You are Bob!
{if:else}
  You're not 30 or Bob. That's all we know.
{/if}

Don’t worry if not all of these make sense. The operators and constructs will be discussed in detail below.

Protected Characters¶

Certain characters must be protected in conditionals to prevent them from being mistaken for regular ExpressionEngine tags:

If you are comparing a variable against a value that might include curly braces, then you should use the HTML entities listed in the table above instead. For example, if you want the conditional to evaluate whether the title is Curly and the Braces: {}, you would write the conditional like so:

{if title == 'Curly and the Braces: {}'}

Boolean Values (True and False)¶

When determining Boolean values the following are considered FALSE:

• the keyword FALSE
• the integer 0
• the floating point number 0.0
• an empty string "" or ''

Everything else is considered TRUE.

Operators¶

The following operators are allowed within conditionals:

{if "ExpressionEngine" ^= "Express"}Yes it does{/if}

{if url $= ".fr"}Your website is from France.{/if}

{if body *= excerpt}Noone expected that.{/if}

{if segment_3 ~ "/^P\d+/"}paginated{/if}

.7 becomes 0.7
7. becomes 7
.20 becomes 0.2
0002 becomes 2
002.5000 becomes 2.5

{if 42.7 $= .7} - false, 42.7 does not end with 0.7
{if 42.7 $= '.7'} - true
{if '42.7' $= '.7'} - true

{if 42.70 $= 70} - false, 42.7 does not end in 70
{if '42.70' $= 70} - true
{if '42.70' $= '70'} - true

{if member_id != '1' && member_group != "5" OR username == "Billy"} Hi! {/if}

{if count % 5 == 0}
  <hr>
{/if}

{if count ** 2 == 25}What a strange way ...{/if}
{if count ^ 2 == 25}... to check if count is 5{/if}

-5 ** 2 == -25
(-5) ** 2 == 25

5 ** -2 == 0.04

{if 2 ^ 3 ^ 2 == 512}this{/if}
{if 2 ^ 3 ^ 2 == 64}not this{/if}

{if segment_1 . '/' . segment_2 == 'site/index'}

{if (member_id == '1' OR member_id == '2') && channel_id == '5'}

Else and Elseif¶

You can use two additional control structures to help tailor your results:

{if:elseif}

And:

{if:else}

These work similar to standard PHP else and elseif constructs. Here is an example:

{if username == "Joe"}
  <h1>Hey, Joe! Where were you Tuesday?</h1>
{if:elseif username == "Bob"}
  <h1>Hey, Bob! Thanks for the tickets!</h1>
{if:else}
  <h1>Welcome to our site.</h1>
{/if}

In the above example, if the currently logged in user has the username of “joe” he receives the first message. If not, ExpressionEngine evaluates the second conditional for the username of “bob”. If the username is neither joe nor bob a default message is shown.

Embedding Tags¶

We recommend not wrapping variables in braces ({}) for example, do this:

{if my_snippet == "hello world"}

instead of these:

{if {my_snippet} == "hello world"}
{if "{my_snippet}" == "hello world"}

Tags still require their braces, for example:

{if {entry_date format="%Y"} == {current_time format="%Y"}}

When using tags pay special attention to your quote marks. If you need more than one level of quotation you will need to either alternate between single and double quote marks, or escape your quotes. For example, instead of this:

{if "{current_time format="%F"}" == "May"}

do this:

{if "{current_time format='%F'}" == "May"}

or this:

{if "{current_time format=\"%F\"}" == "May"}

Short Conditionals¶

Certain conditionals exist in a shortened form in order to improve template readability. These conditionals are usually checking to see if a certain thing is true or exists:

{if logged_in}  Welcome back to the site!<br /> <a href="{path='LOGOUT'}">Logout</a>  {/if}

{if logged_out}
        You aren't a member or aren't logged in.<br />
        <a href="{path='member/login'}">Login</a>  | <a href="{path='member/register'}">Register</a>
{/if}

Global Conditional Variables¶

There are a handful of variables that are always available to conditionals.

{if group_id == '7'}  You're an "Editor"!  {/if}

{if member_group == '7'}  You're an "Editor"!  {/if}

{if member_id == '147'}  Ooh, you're really special, Frank!!  {/if}

{if screen_name == "Mr. Ed"}  Thanks for all your hard work on the site, Ed!  {/if}

{if total_comments < 1}  What??  No one has commented on my site at all?!?!  {/if}

{if total_entries > 1000}  Yowza!  This is one hot site!  {/if}

{if segment_3 == "private"}  You're seeing something private!  {/if}

{if username == "elvira"}  Hi, mom!  I know it's you!  {/if}

Alternative Syntax¶

In order to be able to use some member variables in conditionals inside a channel entries tag, which processes its own member information, it is necessary to use an alternative syntax. All of the member variables may be used in conditionals with the addition of the prefix “logged_in_”.

{exp:channel:entries channel="default_site"}
        {if logged_in_member_id == author_id}
                <p>You wrote this entry!</p>
        {/if}
{/exp:channel:entries}

A list of the available member variables that utilize this alternate syntax follows:

• logged_in_member_id
• logged_in_group_id
• logged_in_group_description
• logged_in_username
• logged_in_screen_name
• logged_in_email
• logged_in_ip_address
• logged_in_location
• logged_in_total_entries
• logged_in_total_comments
• logged_in_private_messages
• logged_in_total_forum_posts
• logged_in_total_forum_topics

Errors¶

In the event that there is a problem parsing or evaluating a conditional an error will be displayed based on your debug preferences. Errors are triggered in the following scenarios:

• {if: is encountered in the template without it being either if:else or if:elseif. For example:

{if:foo}

• {/if} cannot be found. All {/if} inside a string (single or double- quoted) are ignored. For example:

  {if segment_1 == 'site'}HELLO WORLD
  

• There is an unclosed single or double-quoted string. For example:

{if segment_1 == "site}HELLO WORLD{/if}

• A closing } is not found. For example:

{if segment_1 == "site" HELLO WORLD{/if}

• A valid operator is not found. For example:

  {if segment_1 "site"}HELLO WORLD{/if}
  

  or:

  {if segment_1 ==== "site"}HELLO WORLD{/if}
  

• A number followed by a colon (:) was found. For example:

{if 5:2}

• A number has too many periods (.). For example:

  {if 1.2.3}