Set Flow Variable Values from a Visualforce Page

After you embed your flow in a Visualforce page, set the initial values of variables, sObject variables, collection variables, and sObject collection variables through the <apex:param> component.

You can set variables only at the beginning of an interview. The <apex:param> tags are evaluated only once, when the flow is launched.

You can set only variables that allow input access. For each flow variable, input access is controlled by: If you reference a variable that doesn’t allow input access, attempts to set the variable are ignored. Compilation can fail for the Visualforce page, its <apex:page> component, or the Apex class.

The Input/Output Type variable field in the Cloud Flow Designer
The isInput field on FlowVariable in the Metadata API

Note

The following table lists the ways you can set a flow’s variable, sObject variable, and sObject collection variable values using Visualforce.

Method	Variables	sObject Variables	Collection Variables	sObject Collection Variables
Without a controller
With a standard controller
With a standard List controller
With a custom Apex controller
With an Interview Map

Setting Variable Values without a Controller

This example sets myVariable to the value 01010101 when the interview starts.

Setting Variable Values with a Standard Controller

You can use standard Visualforce controllers to set variables by passing in data from a record. This example sets the initial value of myVariable to the Visualforce expression {!account} when the interview starts.

Setting an sObject Collection Variable Value with a Standard List Controller

Because sObject collection variables represent an array of values, you must use a standard list controller or a custom Apex controller. This example sets myCollection to the value of {!accounts} when the interview starts.

Setting Variable Values with a Custom Apex Controller

For finer control over your Visualforce page than a standard controller allows, write a custom Apex controller that sets the variable value, and then reference that controller in your Visualforce page. This example uses Apex to set myVariable to a specific account’s Id when the interview starts.

This example uses Apex to set an sObject collection variable myAccount to the Id and Name field values for every record with a Name of Acme.

Setting Variable Values with an Interview Map

This example uses an Interview map to set the value for accVar to a specific account’s Id when the interview starts.

Here’s a similar example that sets the value for accVar to a new account when the interview starts.

This example uses a map to add two values to a string collection variable (stringCollVar) and two values to a number collection variable (numberCollVar).