How does the Network Dataset builder operate?

For a diagram template based on the Network Dataset builder, the schematic feature classes associated with that diagram template are in relation to in-memory Network Analyst feature classes that are built for each type of network analysis layer input (stops, barriers, incidents, orders, and so forth) as well as real network GIS feature classes (streets, network junctions, and so on) that compose the network analysis result on the network.

When generating a diagram based on the Network Dataset builder, the builder populates the schematic feature classes—that is, it creates the schematic features expected in the diagram as follows:

1. It analyzes the in-memory features that compose the solved network analysis layer and decodes their geometry and topology.
2. For each feature layer that composes the network analysis layer, it verifies whether it is expected to deal with this feature layer—that is, it verifies that a schematic feature class associated with the in-memory feature class related to that feature layer exists for the diagram template.

   If there is such a schematic feature class for the diagram template, for each network feature in the feature layer, it creates in memory the associated schematic feature; evaluates its attributes: cost attributes for network features (ArriveTime, DepartTime, Attr_Meters, Attr_Minutes, Status, CurbApproach, and so on), as well as any other attributes required for the schematic feature (subtype, attributes used for the symbology); and initializes its topology and geometry.

3. If schematic rules are specified for the related diagram template, they are executed on all the schematic features built in memory.
4. If there is a default schematic layout algorithm configured for the diagram template, the algorithm is executed and the geometry for all the in-memory schematic features is updated accordingly.
5. All the schematic features in memory since the generation process started are saved in the schematic feature classes in the schematic dataset.
6. All the created schematic features are queried from the schematic feature classes, and the diagram is displayed.

Then, at any time and for its lifetime—that is, until it is deleted from the schematic dataset—the diagram can be

• Reopened.
• Edited, laid out, and saved.
• Updated so its content stays in coherence with the geodatabase and each change that impacted the associated GIS features is reported on the associated schematic feature. Diagrams based on a versioned network dataset can also be updated from any other reference version; this means that even if diagram generation is based on a specific version of the network dataset at a given time, if this network dataset version is deleted or is no longer the reference version, the diagram reference version can also be changed so the diagram content evolves with the network dataset version.

Note:

Diagram templates based on the Network Dataset builder can also be used to generate mixed diagrams that contain schematic features associated with network features and schematic features coming from custom queries that operate from any type of database. In this case, there are intermediate steps during the generation process:

• Schematic feature classes with custom queries configured to be launched during diagram building—that is, queries with the Query on Generate/Update evaluation mode—are processed just before executing the rules.
• Schematic feature classes with custom queries configured to be launched during diagram loading—that is, queries with the Query on Start Editing evaluation mode—are processed just after executing the rules.

In both cases, the custom query specified on each schematic feature class is executed, and the schematic features related to each queried record are created in memory, their attributes are evaluated, and their topology and geometry are initialized.

Note:

When configuring the Network Dataset builder properties, the builder is set to enable the specific running mode called Automatic schematic feature class creation. When this mode is enabled, the Network Dataset builder is able to deal with any in-memory feature that composes the network analysis result on the network even if, at the time of the generation, there is no schematic feature class associated with its related in-memory feature class. When this running mode is disabled, the Network Dataset builder cannot create the missing schematic feature classes for the diagram template, and schematic features related to all or some of the in-memory features that compose the network analysis result may not be included in the generated diagram.