This is in continuation of my previous post. In this post I am going to introduce you to Geospatial Platform API "Resources" and highlight the differences in "Resources" between AutoCAD Map 3D and Autodesk Infrastructure Map Server (AIMS) [or MapGuide].
In the Geospatial Platform API, resources are the files and configuration information which are essential part of creating Layers (in Map 3D it's the FDO layers in DisplayManager and not the AutoCAD Layers) and Maps. There are some common types of resources available in Map 3D and AIMS; AIMS (MapGuide ) has some additional types. Map 3D And AIMS Developer's guide has the detailed list of resources supported in Map 3D and AIMS.
Resources are stored in a resource repository. The repository is structured like a directory, with documents, folders, and subfolders. Each resource is stored as XML and has a unique path in the repository. The resource’s extension must match one of the types defined in MgResourceType, but the rest of the name and the path is arbitrary. The root’s path is Library:// and the path of a typical resource might be Library://MyProjects/Project1/Roads.LayerDefinition
AutoCAD Map 3D has a single repository named Library. This repository is contained within the DWG file.
AIMS uses multiple repositories. The Library repository contains persistent, site-wide data. There is a single Library repository for each AIMS site. There are multiple Session repositories, each one containing data from a single AIMS session. Session repositories are unique to an individual session and cannot be shared. All AIMS repositories are managed on the site server.
Some resources are self-sufficient and do not refer to any other resources or files. And some resources reference other resources. For example, layers and feature sources are stored as separate resources. A layer resource refers to the resources for the feature sources that are used in that layer.
Resource Service enables us to manipulate resources in Map 3D and AIMS. Though Geospatial Platform API is very consistent between AutoCAD Map 3D and AIMS, but there are some differences in the way they handle resources as AIMS need to manage the resources in a Server-client environment. Allowable resource types are defined as static members of the class MgResourceType.
Resource Types which are common between AutoCAD Map 3D and AIMS - FeatureSource, LayerDefinition, SymbolDefinition.
Following Resources are applicable only to AIMS - ApplicationDefinition, DrawingSource, Folder, LoadProcedure, Map, MapDefinition, PrintLayout, Selection, SymbolLibrary, or WebLayout resources
AutoCAD Map 3D does not use resource headers. They are only used in AIMS / MapGuide to control permissions in the site repository. In AutoCAD Map 3D, pass a NULL parameter for methods that require a resource header, such as SetResource.
Session repositories are not supported in AutoCAD Map 3D. All resources must be stored in the Library repository.
We have a nice video titled 'AutoCAD Map 3D Resource Explorer' which explains working on Map 3D resources with associated code sample. You can view the video online or download it along with the visual studio project.
Attached PDF will help you to understand working with 'Resources' and associated APIs which you would require in your application development using Geospatial Platform API.
I hope this is useful to you!
