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ExpressionEngine

2.8.1 User Guide

Channel Categories Tag

Introduction

The Channel Categories tag enables you to show your Categories in a list. Here is the basic syntax:

{exp:channel:categories}
    {category_name}
{/exp:channel:categories}

Everything contained between the opening and closing tag will be repeated for each category, so if you want to wrap each category with some markup you’ll do this:

{exp:channel:categories}
    <a href="{path='channel/index'}">{category_name}</a>
    {if category_description}{category_description}{/if}
{/exp:channel:categories}

Parameters

backspace=

backspace="5"

Backspacing removes characters (including spaces and line breaks) from the last iteration of the loop. For example, if you put a <br> tag after each category you’ll have this

Local News<br>
Health News<br>
Science News<br>

You might, however, not want the <br> tag after the final item. Simply count the number of characters (including spaces and line breaks) you want to remove and add the backspace parameter to the tag. The <br> tag has 4 characters plus a new line character, so you would do this

{exp:channel:categories style="linear" backspace="5"}
    {category_name}<br>
{/exp:channel:categories}

That will produce code like:

Local News<br>
Health News<br>
Science News

The “backspace” parameter is only allowed if you are using the “linear” style. It is not applicable if you use the “nested” style for the display of the list.

category_group=

category_group="2"

Category Groups are specified by ID number (the ID number of each category group is displayed in the Control Panel). The reason we use the ID is because category groups can be called anything (with spaces, quotes, etc.), and also renamed. It would be much more difficult to have to update the tag parameters every time you updated a category name.

And as with many other parameters, you can stack category groups

category_group="1|2|4"

Or use “not” to exclude categories

category_group="not 2"

channel=

channel="channel_name"

The name (short name) of the channel that the categories are assigned to. This variable is required unless you only have a single channel. Multiple channels may also be specified.

You must specify this parameter if you use the category name in URL feature.

class=

class="my_custom_class"

When using the “nested” style of display (see the style= parameter), this lets you specify the value of the “class” attribute in the opening <ul> tag. The default value is “nav_categories”.

For instance, if you set the parameter as class=”my_custom_class”, then the beginning of the nested category output would be

<ul class="my_custom_class">

disable=

disable="category_fields"

The disable= parameter allows you to turn off aspects of the tag that you might not be using in order to improve performance. Valid options are:

  • category_fields

id=

id="my_custom_id"

When using the “nested” style of display (see the style= parameter), this lets you specify the value of the “id” attribute in the opening <ul> tag. The default value is “nav_categories”.

For instance, if you set the parameter as id=”my_custom_id”, then the beginning of the nested category output would be

<ul id="my_custom_id">

parent_only=

parent_only="yes"

This parameter allows you to limit the category display to only “parent” categories; no sub-categories will be displayed.

restrict_channel=

restrict_channel="no"

This parameter may be used to alter the behavior of the show_empty parameter and has no effect unless that parameter is set to not show empty categories. When restrict_channel is set to “no”, the show_empty parameter will display categories that have no entries from all channels, rather than categories that have no entries from the specified channel. By default, the empty categories shown will be restricted to the specified channel.

show=

show="4|7"

With this parameter, you can specify which categories will be included in the list. For instance, if you wanted to keep a particular category from being listed you could specify only those you wanted displayed to be included. Category IDs are separated by the pipe character to specify more than one category. If you specify a child category be shown, you must also include its parent category to be shown.

You may alternatively specify which categories to not show

show="not 3|6|8"

If you specify that a parent category is not shown, then any children of that parent category are then unable to be shown by the tag. The parent category is required for any and all children categories.

show_empty=

show_empty="no"

This parameter determines whether or not categories that contain no entries for the specific channel are displayed. If you set the parameter to “no” then categories which do not contain entries will not be included in the list. If you want only categories that have no entries assigned from any channels, use the restict_channel parameter in conjunction with show_empty

By default, categories with no entries will be included.

show_expired=

show_expired="yes"

Determines whether expired entries are included when calculating whether a category has entries when the show_empty parameter is set to not show empty categories.

By default, expired entries will not count when determining whether a category is empty.

show_future_entries=

show_future_entries="yes"

Determines whether entries dated in the “future” to are included when calculating whether a category has entries when the show_empty parameter is set to not show empty categories.

By default, future dated entries will not count when determining whether a category is empty.

status=

status="open"

You may restrict to categories with entries with a particular status. The two statuses “open” and “closed” are default statuses that are always available, so you can always specify those if needed. You can choose multiple statuses using a pipe

status="draft|reviewed|published"

Or exclude statuses using “not”

status="not submitted|processing|closed"

By default, the Categories tag will display categories that contain any entries with a status other than closed. This parameter has no effect unless the show_empty parameter is set to not show empty categories.

style=

style="nested"

There are two list “styles” for your categories: “nested” and “linear”.

A “nested” category is one that shows the parent/child hierarchy. It will display the categories as nested “unordered lists” and will automatically enclose the contents in <li> tags and nest them correctly to show the hierarchy:

<ul id="nav_categories">
  <li>News
    <ul>
      <li>Regional</li>
      <li>World</li>
    </ul>
    </li>
  <li>Sports
    <ul>
      <li>National
        <ul>
          <li>Football</li>
          <li>Basketball
            <ul>
              <li>Lakers</li>
              <li>Knicks</li>
            </ul>
            </li>
        </ul>
        </li>
    </ul>
    </li>
</ul>

A “linear” category is one that shows a pure list with no HTML inserted

News Regional World Sports National Football Basketball Lakers Knicks

By default, if you do not specify the “style” parameter then you will get a “nested” list.

When using the “nested” style of display, the opening <ul> tag of the list will have an id of “nav_categories” applied to it. This can be used as a “hook” for javascript or CSS in providing DHTML or other functionality. You may change this by using the id= parameter.

Variables

category_description

{category_description}

This variable simply displays the content from the “category description” field. The variable may also be wrapped in a conditional statement so that it only displays if there is content in the field

{if category_description}{category_description}{/if}

category_id

{category_id}

The category ID associated with the category.

parent_id

{parent_id}

The category ID associated with the category’s parent (or 0 in the case of a top level category).

category_image

{category_image}

The image link (or other information) you can optionally store with each category within the Control Panel.

category_name

{category_name}

This variable simply displays the name of the category.

category_url_title

{category_url_title}

This variable displays the URL title of the category

count

{count}

The “count” out of the current categories being displayed. If five categories are being displayed, then for the fourth category the {count} variable would have a value of “4”.

path=

{path=template_group/template'}

The path (template_group/template) where you want to show the categories. This is typically used within a standard HTML link tag

<a href="{path='channel/index'}">{category_name}</a>

You can also use SITE_INDEX in your path to point to your main site index page. If you show your channel on your home page, using SITE_INDEX is preferable since it will make the URL cleaner.

<a href="{path='SITE_INDEX'}">{category_name}</a>

total_results

{total_results}

The total number of categories being displayed.

Custom Category Fields

All custom fields assigned to a category can be accessed using the “short name” of the field:

{class} {extended_description} {category_name_fr} etc..

These are totally dynamic in that any field you create for your category will automatically be available by its “short name” as a variable.

Conditional Variables

active

<a href="{path='news/index'}"{if active} class="active"{/if}>{category_name}</a>

You may use this conditional to test whether the category shown is the active category or not, based on the dynamic URI segment.

Category Dropdown Menu

You can also display categories in a dropdown menu using the following code:

<form name="catmenu" action="">
    <select name="selcat" onchange="location=document.catmenu.selcat.options[document.catmenu.selcat.selectedIndex].value;">
        <option value="">--Select Category--</option>
        {exp:channel:categories channel="yourchannel" style="linear"}
            <option value="{path='channel'}">{category_name}</option>
        {/exp:channel:categories}
    </select>
</form>

Examples

Here are a few examples of the categories tag in use

{exp:channel:categories channel="news" style="linear" backspace="7"}
    <a href="{path='news/entry'}">{category_name}</a><br />
{/exp:channel:categories}

This code would create a list of the categories in the “news” channel and link to the “news/entry” Template. It would also remove the <br /> from the last entry.

{exp:channel:categories channel="politics" style="nested"}
    <a href="{path='SITE_INDEX'}">{category_name}</a>
{/exp:channel:categories}

This code would create a nested, unordered list of the categories from the “politics” channel as links to the main channel page.

User Contributed Notes

Posted by: Derek Hogue on 3 January 2014 2:27pm
Derek Hogue's avatar

Note that this is not the tag to use if you’re looking to output the categories which have been selected for a particular channel entry - use the {categories} tag pair for that.

Posted by: Hop Studios on 27 September 2013 1:51am
Hop Studios's avatar

Tips if it’s not working:

If a category group is not assigned to any channel, then you can’t use this tag—it won’t display categories from a group that’s unassociated with any channel.

The “channel” attribute is required unless:

* you have only one channel, AND
* you aren’t using category names in your URLs (i.e. that setting is turned off—not just that you aren’t doing it)

Posted by: Ian Ebden on 1 March 2012 7:28am
Ian Ebden's avatar

If you’re after a nested category dropdown menu with grouped options using <optgroup>, try this:

<form name="catmenu" action="#">
 <
select name="selcat">
  <
option value="">Filter by Category</option>
  
{exp:channel:categories cache="yes" refresh="60" channel="news" disable="category_fields" style="linear"}
  {if parent_id 
== '0'}{if count != '1'}</optgroup>{/if}<optgroup label="{category_name}">{/if}
  {if parent_id 
!= '0'}<option value="http://expressionengine.com/directory">{category_name}</option>{/if}
  {
/exp:channel:categories}
 
</select>
</
form
Posted by: Hop Studios on 16 February 2012 8:26am
Hop Studios's avatar

Be aware:

show_empty="no" 

doesn’t take into account the status of entries (“closed”, for instance), or the entry dates in the future or expiration dates in the past. So you might think a category is “empty” but to EE, it’s not.

You must have an EllisLab product license and have at least 50 posts to the community forums to contribute notes to the User Guide