You can use the following translation keys to translate buttons in EXT:form.
element.Form.renderingOptions.submitButtonLabel
element.Page.renderingOptions.previousButtonLabel
element.Page.renderingOptions.nextButtonLabel
element.SummaryPage.renderingOptions.previousButtonLabel
element.SummaryPage.renderingOptions.nextButtonLabel
These allow to localize button labels globally for all forms equally.
You can set translated custom labels for specific forms, too. Please mind the special position of the form-identifier inside the translation key only for the submit button (seems a bug):
element.<form-identifier>.renderingOptions.submitButtonLabel
To translate previous and next buttons for specific forms, you can use the element-identifiers. You can also combine these with a form-identifier.
Form definition (excerpt):
renderables:
-
renderingOptions:
previousButtonLabel: 'Previous step'
nextButtonLabel: 'Next step'
identifier: summarypage-1
label: 'Summary page'
type: SummaryPage
Translation keys:
<form-identifier>.element.<element-identifier>.renderingOptions.nextButtonLabel
element.<element-identifier>.renderingOptions.nextButtonLabel
<form-identifier>.element.<element-identifier>.renderingOptions.previousButtonLabel
element.<element-identifier>.renderingOptions.previousButtonLabel
Example keys for the form definition above:
MyContactForm.element.summarypage-1.renderingOptions.previousButtonLabel
element.summarypage-1.renderingOptions.previousButtonLabel
Limitation: You can not translate previous and next buttons when combining the form-identifier
and the general element-type
(like 'SummaryPage').
The following won't work:
<form-identifier>.element.SummaryPage.renderingOptions.nextButtonLabel