Custom forms are a way of viewing, updating, synthesizing, and collecting information in the field with ArcPad. Forms are created in ArcPad Studio and stored as ArcPad XML. ArcPad supports customization of four kinds of forms:
- Edit forms
- Identify forms
- Query forms
- General forms
Layer definition files provide the way of delivering custom forms with associated scripts to handle data entry validation and other features offered on the forms. Layer definitions are stored in the ArcPad AXF file or in a file associated with the shapefile. This file has the same filename prefix as the shapefile, but has an .apl extension. The layer definition file lives and travels with the shapefile.
General forms can also be delivered via applets and default configuration files.
Edit forms are used for data collection such as updating the values of a feature’s attributes. Each edit form you create must be associated with a specific layer (shapefile or ArcPad AXF file layer) and replaces the Feature Properties dialog box for that layer. Each layer, therefore, can only have one associated edit form. The edit form can, however, contain multiple tabs.
Identify forms replace the Feature Properties dialog box and are used to view, but not edit, a feature’s attributes. This allows you to view data in a different style when a feature is being identified as opposed to when it is being edited. Like edit forms, each identify form you create must be associated with a specific shapefile or ArcPad AXF layer. If no identify form is supplied, but an edit form is supplied, the edit form is displayed in identify mode. Whether you are creating an edit or identify form, you can link your form controls, such as textboxes or comboboxes, to attributes in a specified layer. In other words, the values that are viewed and/or edited via the form controls directly correspond to the values from the associated layer.
Query forms are used for customization of how searches are performed on a layer. The Query form is displayed in the Find dialog box as the first tab(s), before the default Query tab. Each layer can only have one associated query form, however this query form can have multiple tabs. The Find dialog box displays the query forms for all of the layers in the map.
General forms are created without any association with a layer. That is, an applet can provide a custom toolbar with a userdefined command that displays a form. The form takes input from the user, performs several calculations, displays a message to the user, and closes.
You would use a general form, for example, if you wanted to perform and view statistics for a tree layer such as median tree height, average DBH, or tallest tree. You would create a form that provided you with on-the-fly calculation of selected data, in this case the tree layer. Once you are finished, you simply close the form.