What's new in ModelBuilder in ArcGIS 10
Many enhancements have been made to ModelBuilder.
- The ModelBuilder toolbar and menus have been updated.
- Undo and redo are now supported.
- Model elements now have ToolTips. You can pause your mouse cursor over any model element and see its parameter values.
- There are new tools specifically designed for ModelBuilder. These tools fall into two basic categories: Iterators and Model Only tools. See the next two sections for more information about these tools.
- The default spacing between elements has changed from 30 to 15.
- Twelve new Iterators have been added to be used for iteration or for repetitive tasks in a model. Ten of these iterators are implemented as geoprocessing tools.
- Iterators replace the series option in Model Properties available in ArcGIS versions prior to 10.
- Using an Iterator in a model disables the 9.3 Iteration options in Model Properties and sets a default value of -1, which simply means that the model will run for unlimited times or based on the number of inputs in an Iterator, and not on a set number.
- If a model containing an iterator is exported to a Python script, the script will not include the iteration logic.
The new Iterators are
- For iterates over a starting and ending value by a given value. It works exactly like For in any scripting/programming language, executing through a set number of items.
- While works exactly like While in any scripting/programming language, executing while a condition is true.
- Iterate Feature Selection tool iterates over features in a feature class.
- Iterate Row Selection tool iterates on rows in a table.
- Iterate Field Value tool iterates over each value in a field.
- Iterate Multivalue tool takes a list of inputs and runs the model for each value.
- Iterate Datasets tool iterates over datasets in a Workspace or Feature Dataset.
- Iterate Feature Classes tool iterates over feature classes in a Workspace or Feature Dataset.
- Iterate Files tool iterates files in a folder.
- Iterate Rasters tool iterates over Rasters in a Workspace or a Raster Catalog.
- Iterate Tables tool iterates over tables in a workspace.
- Iterate Workspace tool iterates over workspaces in a folder.
Model Only tools
Model Only tools only work in ModelBuilder and not as stand-alone tools or in scripting. There are seven Model Only tools, of which four (Collect Values, Get Field Value, Parse Path, and Stop) have been added at 10.
- Calculate Value returns a value based on a user-specified Python expression in a tool dialog box.
- Collect Values is designed to collect the output values of an Iterator. If you are not iterating the model, collect values can be used to convert a list to a multivalue in cases where it does not make sense to use the single output as input to a tool like merge, append, mosaic, intersect, and union.
- Get Field Value gets the field value from any input. This tool differs from the Iterate Field Value tool, as it gets only a single value from a field or the first value from a field of a table with many records.
- Merge Branch merges two or more logical branches into a single output.
- Parse Path parses the input into its File, Path, Name, or Extension. The output could be used as in-line variables in the output name of other tools.
- Select Data selects an element in a parent data element. The Select Data tool is used with tools that output a folder, geodatabase, feature dataset, or coverage. Select Data allows access to the data stored inside, such as feature classes or tables.
- The Stop tool exits the model out of an iteration loop if the input value is set to True or False. It is functionally similar to the While Iterator, but is useful to stop a model in the case where While Iterator in the model and additional Iterators cannot be added.
Save dialog box has a create new toolbox button
For new models created using the ModelBuilder button, the Save dialog box now has a create new toolbox button.