Introduced with ArcGIS 10.1, Python Add-ins provide the newest mechanism for customizing an ArcGIS Desktop application (e.g., ArcMap). These add-ins take scripting to the next level by providing the ability to incorporate user interface elements (e.g., buttons, tools and toolbars) into the customization.
The Set Scale Band for ArcGIS 10.1 template includes a Python add-in, which can be used by ArcGIS for Maritime: Charting users working in the Nautical Information System (NIS) geodatabase to filter data by scale band and/or product type. It consists of a toolbar (NIS Scale Band) containing three combo box controls (Low, High, and Products) and two command buttons (Set and Clear):
In the enterprise workflow of the ArcGIS for Maritime: Charting solution, the NIS functions as a multi-scale central database in which all features are stored in one set of feature classes regardless of scale. Each feature has an attribute ( PLTS_COMP_SCALE) that specifies its compilation scale. The value of this attribute is set when the feature is created and only modified in cases where the feature is conflated with other redundant features to apply across multiple scale bands.
Every feature has another attribute (NIS_PRODUCTS) that controls how the NIS feature interacts with products such as charts or ENCs. The default value for this attribute is ALL, which means the feature will appear on all relevant products. In some cases, you may want to maintain features in the NIS that only appear on chart products, but not on ENCs. In that case, you would set NIS_PRODUCTS = CHART which would include the feature in chart product replicas, but exclude it from others. You can even maintain features in the NIS that do not appear on any products, i.e. they are NIS-only features. In this case, you would set NIS_PRODUCTS = NONE.
The Set Scale Band add-in is being posted for two reasons:
1) The add-in is useful right out of the box as a tool to simplify working in the NIS and
2) The Python source code provides an excellent sample project for creating other add-ins.
Using Set Scale Band
The Set and Clear command buttons operate on a selected ArcMap Table of Contents item including:
- A feature layer
- A group layer
- A data frame
If an NIS editor is applying source at a particular scale, they can use the add-in to show only features in that scale band. If an NIS editor has applied the source to the largest scale and now wants to generalize those features up through the smaller scales, they can create two group layers and they can use the add-in to set one group to the larger scale and the second group to a smaller scale.