What is Expression Builder?

The Expression Builder tool in ArcPad Design Mode allows you to build expressions for the Quick Fields feature to use. After building expressions on your Windows device, you can move your expressions to Windows Mobile to use, similar to moving applets that you create on the desktop onto your Windows Mobile device.

You can build expressions based on built-in functions such as a unique ID, username, or GPS X coordinate. You can string functions together to create custom expressions, and you can add free form text to your expression.

Each expression is stored in a file called ArcPadExpressions.apx. TheArcPadExpressions.apx file must always accompany the ArcPadPrefs.apx file. By default, both of these files are located in the My Document\My ArcPad folder. If you place your ArcPadPrefs.apx file somewhere other than the default location (for example, in a project folder along with an app shortcut), ensure that you place the ArcPadExpressions.apx file in the same location.

You can copy an ArcPadExpressions.apx file created in Windows to your device to use Quick Fields on Windows Mobile.

The Expression Builder is a wizard that helps you define the content that will populate your nominated Quick Field. The first option in the wizard is to add a new expression or delete an existing expression. If you're adding an expression, you then decide if you want to create an expression for a specific field in a specific layer (for example, define an expression that is a composite of "UserName" and "UniqueId" for a field called UniqueSiteCode in the layer called Sites), or to create an expression that will be used for all fields of the same name, regardless of layer, in other words, a global expression (for example, define an expression of "UserName" for any field called Name in any open layer). After defining a name for the expression, you can choose from a list of grouped functions to build your expression.