ConditionalFieldsAndSteps.md

Conditional fields

The data from previous steps can be used to only show fields in certain conditions.

renderer = Neos.Fusion.Form:Runtime.RuntimeForm {
    process {
        content = afx`
            <Neos.Fusion.Form:FieldContainer 
                @if.hasOtherValue = ${data.otherValue}
                label="Conditional Field" 
                field.name="conditionalField"
            >
                <Neos.Fusion.Form:Input />
            </Neos.Fusion.Form:FieldContainer>
        `
    }
}

This also allows to make whole form steps conditional:

renderer = Neos.Fusion.Form:Runtime.RuntimeForm {
    process = Neos.Fusion.Form:Runtime.MultiStepProcess {
        steps {
            address {
                ...
            }
            visa {
                @if.fromForeignGalaxy = ${data.galaxy != 'milkyway'}
                ...
            }
        }
    }
}

If a field shall always be present but required once other fields are filled, the schema can be adjusted via @process and @if.

renderer = Neos.Fusion.Form:Runtime.RuntimeForm {
    process {
        schema {
            conditionalField = ${Form.Schema.string()}
            conditionalField.@process.makeRequired = ${value.isRequired()}
            conditionalField.@process.makeRequired.@if.hasOtherValue = ${data.otherValue || request.arguments.otherValue}
        }
    }
}

The condition checks the submitted data from the current request request.arguments.otherField and the successfully submitted data from previous requests data.otherField.