Autogenerating Forms - Conditional Submit

index.js

onSubmit={({ component }) => {
  // TODO: Contact some API with the data
  console.log("submitting", component.getValues());

  // Simulate response from API saying that email address is already in use and report this
  // error to the user
  if (component.get("fields.email.value") === "[email protected]") {
    component.set({ "fields.email.err": "already in use" });
  } else {
    // Everything was successful so redirect, show confirmation, etc...
  }
}}