CONDITIONALS

A command library for creating conditional blocks. The if command is the basic tool for making optional logic, while the choose command with its associated child commands when and otherwise works well for creating mutually exclusive logic blocks. 

if

If forms a basic conditional block whose child commands are evaluated only if the expression in the test attribute evaluates to a Boolean value of true.

Child commands

Any command can be a child of if. There should be at least one child, as a conditional block without content serves no purpose.

Attributes

test
Required	Value type	EL-evaluated
Yes	Boolean	Yes
The conditional expression. Should the resolved value be true, the child tags are evaluated, otherwise they are not.

Examples

To make use of if, place the commands you wish to make conditional as its children. Make sure that the EL expression for the test attribute evaluates into a Boolean value.

<if test="${mainOpportunity.IsClosed}">
  <set var="statusMessage" value="Opportunity is closed.">
  <next step="endScreen">

choose

The choose command presents a set of conditional blocks, of which only one will have its contents processed.

There should be one or more when commands as children, each with its own condition. If the condition of one of them evaluates to a Boolean true, the children of that when are processed and the remaining children of choose are skipped. Otherwise that when is skipped and the condition of the next when command is evaluated.

The last child of choose may be an otherwise command. Its contents will be processed if all of the preceding when commands were skipped.

Child commands

• when
  Required. At least one of these is required to be among choose's children.
• otherwise
  Optional. One, and only one, otherwise can be a child of choose. Preferably as the last child after the when commands.

Examples

The choose command must be used with the when and otherwise commands as its children.

<choose>
  <when test="${oppLineItem.Quantity >= 1000}">
    <set var="quantityDesc" value="High">
  <when test="${oppLineItem.Quantity < 10}">
    <set var="quantityDesc" value="Low">
  <otherwise>
    <set var="quantityDesc" value="Medium">

Note that the order of the child commands matters. The otherwise command always finishes the choose block, so any when commands after an otherwise never do anything. In this example of how not to do things, the "response" variable will never end up having "Yes." as its value.

<choose>
  <otherwise>
    <set var="response" value="Ask again later.">
  <when test="${areWeThereYet}">
    <set var="response" value="Yes.">

when

A child of a choose command. The children of when are evaluated if the condition of the test attribute resolves to a Boolean true.

Parent commands

• choose
  Required. This must be the parent command.

Child commands

Any command can be a child of when. There should preferably be at least one child.

Attributes

test
Required	Value type	EL-evaluated
Yes	Boolean	Yes
The conditional expression. Should the resolved value be true, the child commands are evaluated, otherwise they are not.

Examples

See the documentation of choose for examples.

otherwise

A child of a choose command. The children of otherwise are evaluated if the contents of none of the preceding when command were evaluated.

Parent commands

• choose
  Required. This must be the parent command.

Child commands

Any command can be a child of otherwise. There should preferably be at least one child.

Examples

See the documentation of choose for examples.