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- ---
- title: Mark Required Fields As Such
- order: 61
- layout: page
- ---
-
- [[mark-required-fields-as-such]]
- Mark required fields as such
- ----------------------------
-
- Don’t make your users guess which fields in your form are required. Mark
- them as such:
-
- [source,java]
- ....
- TextField tfFirstName = new TextField("First name");
- tfFirstName.setRequired(true);
- tfFirstName.setRequiredError("First name must be filled in!");
- ....
-
- Required fields get a small *asterisk* after the caption (or after the
- field itself, if it doesn’t have a caption), which is quite universally
- understood to mean “required”. Of course, it certainly doesn’t hurt to
- have “footnote” somewhere in your form that explains it anyway.
-
- image:img/reqfield.png[Required field with asterisk]
-
- Marking a field as required also implicitly adds a non-empty validator
- to the field, preventing the form from being submitted unless a value
- has been entered. The error message associated with that validator can
- be set with the *setRequiredError()* method:
-
- [source,java]
- ....
- TextField tfFirstName = new TextField("First name");
- tfFirstName.setRequired(true);
- tfFirstName.setRequiredError("First name must be filled in!");
- ....
-
- image:img/errortooltip.png[Required field with error]
-
- Think carefully about which fields really are required, though. For
- instance, asking unnecessary questions in a sign-up form has a tendency
- to make people either cancel signing up, or enter nonsense information
- in fields they deem nonessential. Only mark as required fields that you
- really need the user to fill in, right there and then.
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