Forms

Forms

A form is a window the user works in: a document being entered, a list of products, a report with its settings. The same form runs in the desktop application and in the browser.

Generated or drawn

An object with no form of its own gets a generated one: the platform builds it from the object's attributes and tables. That is enough to start, and it keeps up with the metadata.

To control the layout, add a form under the object's Forms, then set it as the default in the object's properties: default object form, list form, choice form.

The form editor

Opening a form shows two tabs:

• Designer: the layout.
• Code: the form's module, its event handlers and procedures.

Beside the layout:

Panel	What it holds
Attributes	The data the form works on. The main attribute is the object the form was opened for; add more for anything else the form keeps
Commands	Actions the form offers: buttons, menu items
Tree elements	The controls on the form, as a tree, in the order they are laid out

Drag an attribute onto the form and a control bound to it appears: a text box for a string, a check box for a boolean, a table for a tabular section. Changing the field changes the data, and the reverse.

Controls

Text box, check box, radio button, button, table, tool bar, notebook (tabs), frame, static text and line, gauge, slider, HTML box, chart, and the sizers that lay them out (box, grid, wrap, static box). Each control's properties include its events.

Layout

Controls are placed by sizers, not by coordinates. A form therefore resizes, changes language and font size, and moves to the browser without being redrawn.

Code on a form

An event in a control's or the form's properties is bound to a procedure in the form's module. Rename or delete the handler in the editor and the designer offers to rename or delete the procedure with it.

Do not assume data exists when the form opens. The designer previews forms without running their data reads, so an open handler has to tolerate an empty source.