When creating or modifying ontologies in Composer, imports can be viewed and specified in the Imports View.
When you open a model created with another tool, TopBraid Composer will attempt to resolve the imports. It will search through your workspace and it will look for imported models on the web.
When Composer is started, the internal File Registry scans the current folder structure and inspects the first few lines of all files with a suitable suffix (e.g., .ttl, .rdf, .rdfs) to determine the base URI defined in these files. Then, if an ontology imports another ontology, Composer would try to locate a local copy of the ontology's namespace. If a local file is found, it will always load from the file, so that users don't need to have an internet connection. The goal of this mechanism is to let the system do the right thing automatically in the background, without users having to worry about it.
If the workspace contains multiple copies of the same namespace, for example multiple versions of a file, then the import will be resolved against the most recent file (using the file's time stamp). You can override this behavior by opening the non-primary file explicitly.
If an imported ontology exists in your workspace, but Composer did not find it, check the namespace definitions. The namespace defined in the imported ontology xml:base statement should match exactly the namespace specified in the owl:import statement.
If Composer does not find the imported ontology in your workspace, it will look for it on the web. If the ontology is found on the web, Composer will examine its xml:base statement. If any of your local files has the same xml:base statement as the ontology on the web, Composer will substitute the local file for the web version.
This means that Composer is able to use the web to resolve some inconsistencies between ontology URIs as identified in xml:base and owl:import statement. This is done transparently, without notifications or warnings. It also means that imports 'working' when you are web connected may not work as expected when you are off-line.
Imported objects are displayed in Classes, Properties and Instances views using a 'grayed out', faded icon. They can be edited in the same way as objects defined in the importing ontology:
You can navigate to the definition of an imported resource in its imported model from the Name field in the Form Panel of Resource Editor. You can also navigate to an imported ontology from the Ontology Overview.
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