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