Last updated September 4, 2013. Created by peterpoe on July 28, 2012.
Edited by myglobaldata_gil, aaronbauman. Log in to edit this page.

Define dependencies between fields based on their states and values.
Conditional Fields for Drupal 7 is a user interface to the new States API, plus the ability to modify fields appearance and behavior on certain conditions when viewing content.

This documentation applies to Conditional Fields for Drupal 7. The documentation for the D6 version, with upgrade instructions, is here.

Overview

The Conditional Fields module allows you to manage sets of dependencies between fields. When a field is “dependent”, it will only be available for editing and displayed if the state of the “dependee” field matches the right condition.
When editing a node (or any other entity type that supports fields, like users and categories), the dependent fields are dynamically modified with the States API.
You can, for example, define a custom “Article teaser" field that is shown only if a "Has teaser" checkbox is checked.

Installation

Install as usual, see Installing contributed modules (Drupal 7) for further information.

Usage instructions

Before adding a dependency, you will have to create at least two fields in the same content type or other fieldable entity like user, comment or vocabulary. For simplicity, we will refer to dependencies attached to content types, but the same instructions apply to all entity types.
Dependencies are listed in a sitewide overview page at admin/structure/dependencies. You can filter the overview by entity type by clicking on the corresponding tab. For added convenience, a "Manage dependencies" tab is also available to the right of the "Manage fields" tab of every content type.

The overview page
In the dependency overview page, you will see a table with 4 columns:

  • Dependent: The field that is controlled by the dependee.
  • Dependee: The field that controls the dependent.
  • Description: A textual description of the dependency.
  • Operations: Buttons to add, edit or delete a dependency.

The last row of the table is used to add a new dependency. Select the Dependent, the Dependee and two basic options "state" and "condition". If you are not sure about these two options, don't worry, you will be able to change these later. Click on the "Add dependency" button.

You are now on the dependency settings page. Before digging into the details of each option, let's understand how a dependency works:

A dependency comes into play in two distinct contexts: when creating/editing a node, and when viewing a node (remember that the same applies to users, comments, categories, etc). The two contexts are independent: you can set up a dependency that acts on node edit and does nothing on node view, and vice-versa.
Basically, a dependency acts as a trigger: if the dependee field meets a certain condition, then a certain state is applied to the dependent field. The dependency is biunivocal and every state has a converse, so the following also applies: if the dependee does NOT meet a certain condition, then the converse of state is applied to the dependent.
When editing a node, the dependency is evaluated by the Javascript States API).
When viewing a node, the dependency is evaluated server-side by Conditional Fields.

Dependency edit page

Now we are ready to examine each option:

Condition

This is the condition that dependee should meet to trigger the dependency.
Available options:

  • Filled: The dependee has at least one non-empty value.
  • Empty: The dependee has an empty value (empty string or array).
  • Touched: The dependee has received focus at least once.
  • Untouched: The dependee has never received focus.
  • Focused: The dependee is currently focused.
  • Unfocused: The dependee is currently not focused.
  • Checked: The dependee is a checkbox and is checked.
  • Unchecked: The dependee is a checkbox and is not checked.
  • Value: The dependee has a certain value or set of values (see below).

The "Value" condition is special in a very important way: it's the only condition that has ANY effect on view context, since it's the only one that allows server-side evaluation. Also, if the "Value" condition is selected, a set of specific options is presented to the administrator.

Values input mode ("Value" specific option)

This lets the administrator choose the way she wants to insert the value or set of values that will trigger the dependency. Whenever an options is selected, the corresponding value(s) field appears below.
Available options:

  • Insert value from widget: Use the actual form widget to insert the desired values. This is a quick but limited way to set up simple dependencies.
  • Regular expression: Use a text field to insert a regular expression.
  • All these values (AND): Use a text area to insert a list of values.
  • Any of these values (OR): Use a text area to insert a list of values.
  • Only one of these values (XOR): Use a text area to insert a list of values.
  • None of these values (NOT): Use a text area to insert a list of values.

Interaction with other dependencies

This field governs the way this dependency interacts with other dependencies that have the same dependent.

Edit context settings

These settings apply when a node is being added or edited in a form.

Form state

The Javascript form state that is applied to the dependent field when the condition is met.
Note: this has no effect on server-side logic and validation. Keep this in mind, since this can lead to counter-intuitive results. For example, if you choose "Invisible" as a form state, the dependent will be HIDDEN when the dependency is TRIGGERED in the form. But when you view the node (and the "Hide the dependent if the dependency is not triggered" option is active, see below), the dependent will be VISIBLE, since the dependency is triggered!
Some options have additional settings (like animations) that appear below when selected.

After "Form state", there are some advanced options that cover peculiar use cases, which are self-explanatory. You can even set up per-role sets of options.

View context settings

These options are also self-explanatory. You can set up per-role sets of options here as well.
Just keep in mind one important thing: in view context, options that need to evaluate if the dependency is triggered or not work only if "Condition" is "Value".

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