Using Conditional Rules

This page describes using conditionals in Webform 4.
This page is still incomplete and requires more information.

Conditionals were brought into Webform core starting version 4 (7.x-4.x).

Terminology

Component - one of current webform's fields.
Conditional - single set of rules, rule collation type and targets.
Rule - single set of comparison source, value and type. Source is a component, value is a component's value and type is a comparison type (equal, not equal etc.).
Rule collation type - AND or OR. Defines how results from multiple rules conditions will be collated. AND - all rules must pass the condition, OR - only one rule must pass the condition.
Target-component which will be shown or hidden based on condition.

Creating a condition

1. Before you begin, you need to create all the components involved in condition logic (both source and target components).
2. Take a look at tabs above. In Webform page of the node, between Form components and E-mails, you will find a tab Conditionals. Hit it. You should end up in /node/[nid]/webform/conditionals page.
   If you cannot find the tab, make sure you are using Webform 7.x-4.x. If you updated from 7.x-3.x, try clearing caches.
3. Click on + button to create condition. Choose the source (triggering component of condition), comparison type and value to create a condition. As a reaction, choose the field which will be shown or hidden.

Really simple example:

if -Choose your country- -is- -USA-
then -show- -Select your state-

.

Multiple Conditionals

Giving a components structure (conditional, not hierarchical)

Field1
|-Field11
--|--Field111
--|--Field112
|-Field12
--|--Field121
--|--Field122

conditionals rules need to be created for each combination of all parent values as rules to both show and hide components in hierarchy.
This allows to provide proper parent-child-grandchild cascading behavior.

I.e. for field Field111 there are 2 conditionals to be created:
1. Field 1 == 11 AND Field11 == 111 => SHOW Field111
2. Field 1 != 11 OR Field11 != 111 => HIDE Field111
NOTE: AND is used for all SHOW, and OR - for all HIDE rules.

Each time a component is hidden, it's value is reset. This works for cascaded hide as well (provided that HIDE rule exists).

Examples and best practice

Here is a list of examples on how to use conditionals.
This is a work in progress, please feel free to contribute.

Show a component dependent on the url

If you are using a webform on multiple nodes (e.g. in panels or in a block) you can use a conditional to show or hide specific components dependent on the current url. And here is how:

1. create a hidden / private text component that will not be visible for the enduser
2. give this component a default value by using a url token; e.g. the [current-page:url:args:last] token will get the last part of the url (e.g. /europe/germany/[cologne])
3. Now this hidden component can be used on the conditionals tab
   
   if [hidden component] contains "cologne" then show [another field]

This will save you from creating multiple webforms which only differs in url specific components.