Fields

Mateu infers the UI element from the java fields inside a class.

So a String fields maps to an input element in the UI, an int field maps to an input element which only allows integers, a boolean field maps to a checkbox, and an enum field maps to a radio button and so on.

Mateu does his best to infer the UI from our java code. However, some times we need to change the default behavior for adjusting the UI.

This is the list of supported field types:

Field type	Painted as	Comments
String	Text field	A rich text editor will be used by annotating the field with @RichText. Also, @Image will treat you string value as the src attribute for an image element. If you annotate your field with @ValuesProvider or @ValuesProviderMethod a dropdown will be shown.
int, Integer	Number field
float, Float	Number field
double, Double	Number field
boolean, Boolean	Checkbox	Can paint a radio button or toggle by annotating the field with @UseRadioButtons and @Toggle
enum	Dropdown
Arrays and collections of basic types	Text field	Values are separated by commas
Arrays and collections of enums	Check boxes
Arrays and collections of objects	Table
Maps	Not supported
Icon	An icon	More than 600 icons are supported as per today
Any object	Read only showing the toString result	Use a button to open an editor

The field label is inferred from the field name so, for a field named yourBirthDate, Mateu will create a label saying Your birth date. You can always set an specific value by using the @Caption annotation.

Validations

Mateu looks for JSR-380 javax standard validation annotations to set validations. The validation happens both at client and at server side, even though not all of them are supported at client side.

This is the list of client side supported validations:

• @NotNull, @NotEmpty
• @Min, @Max
• @Pattern

Which fields are visible in the UI

Mateu does not infer a UI component for every field. If the field is final, transient, if it is injected with @Autowiredor if the field is annotated with @Ignored Mateu will ignore them.

Limit possible values

For limiting the number of possible values that the user can enter for an String, int or double field we can use the @ValuesProviderMethod annotation and provide the name of a method returning List<Value> in the same form class. We can also annotate our field with @ValuesProvider and provide a class implementing the ValuesListProvider interface.

Group fields

We can set the number of columns of the form by annotating the class with @FormColumns or by using the columns parameter in the @Section annotation.

We also have several annotations for changing the layout of our form: @Section, @FieldGroup, @Tab, @SameLine, ...

Basically, a form contains one or more sections, each section contains one or more field groups, each field group contains one or more field lines and each field line contains one or more fields. On top of that the form will layout the field lines in columns which can be set at form level or at section level. Each section belongs to a tab, if used.

Please notice that for sections you can remove the line around by setting the card parameter to false.

Run action on value change

You can trigger action runs on a value change. For doing that you just need to annotate the field with @CallActionOnChange and a round trip to the server will happen each time you change that field value.