feat: allow replacing a registered link resolver

code/internal/+openminds/+internal/+resolver/LinkResolverRegistry.m

@@ -15,23 +15,33 @@
     end
 
     methods
-        function addLinkResolver(obj, resolver)
-        % Add a resolver instance to the registry (no duplicates by handle).
+        function addLinkResolver(obj, resolver, options)
+        % Add a resolver to the registry, at most one per IRI prefix.
+        %
+        %   By default a resolver whose prefix is already registered is
+        %   ignored, so registering at startup is idempotent. Pass
+        %   Replace=true to swap the registered resolver for this one,
+        %   keeping its position: a library that reconfigures, for example
+        %   with a new server or credentials, re-registers rather than
+        %   mutating the resolver it registered earlier.
             arguments
                 obj (1,1) openminds.internal.resolver.LinkResolverRegistry
                 resolver (1,1) {mustBeA(resolver, "openminds.interface.LinkResolver")}
+                options.Replace (1,1) logical = false
             end
 
-            if obj.hasResolverForPrefix(resolver.IRIPrefix)
-                % Already registered
-                return
-            end
+            existingIndex = obj.indexOfPrefix(resolver.IRIPrefix);
 
-            obj.LinkResolvers{end+1} = resolver;
+            if isempty(existingIndex)
+                obj.LinkResolvers{end+1} = resolver;
+            elseif options.Replace
+                obj.LinkResolvers{existingIndex} = resolver;
+            end
+            % Otherwise already registered; keep the existing resolver.
         end
 
         function tf = hasResolverForPrefix(obj, iriPrefix)
-            tf = any( cellfun(@(r) r.IRIPrefix == iriPrefix, obj.LinkResolvers) );
+            tf = ~isempty( obj.indexOfPrefix(iriPrefix) );
         end
 
         function resolver = getLinkResolver(obj, IRI)
@@ -70,6 +80,11 @@ function reset(obj)
     end
 
     methods (Access = private)
+        function index = indexOfPrefix(obj, iriPrefix)
+        % Position of the resolver registered for a prefix, or empty.
+            index = find( cellfun(@(r) r.IRIPrefix == iriPrefix, obj.LinkResolvers), 1 );
+        end
+
         function promoteResolver(obj, index)
         % promoteResolver - Reorder registry so the resolver at index is first
             arguments

code/internal/+openminds/registerLinkResolver.m

@@ -1,14 +1,25 @@
-function registerLinkResolver(linkResolver)
+function registerLinkResolver(linkResolver, options)
 % registerLinkResolver - Register a link resolver in the link resolver registry
 %
+%   openminds.registerLinkResolver(linkResolver) registers a resolver for
+%   the identifier prefix it declares. Registering a prefix that is
+%   already registered does nothing, so calling this from library startup
+%   code is idempotent.
+%
+%   openminds.registerLinkResolver(linkResolver, Replace=true) replaces
+%   the resolver registered for that prefix with this one. Use this when
+%   a library reconfigures, for example connecting to a different server,
+%   and needs its new resolver to take effect.
+%
 %   See also: 
 %       openminds.interface.LinkResolver
 %       openminds.internal.resolver.InstanceResolver
 
     arguments
         linkResolver (1,1) {mustBeA(linkResolver, "openminds.interface.LinkResolver")}
+        options.Replace (1,1) logical = false
     end
 
     resolverRegistry = openminds.internal.resolver.LinkResolverRegistry.instance();
-    resolverRegistry.addLinkResolver(linkResolver);
+    resolverRegistry.addLinkResolver(linkResolver, "Replace", options.Replace);
 end

tools/tests/unitTests/ResolverTest.m

@@ -140,6 +140,33 @@ function testResolverRegistryPromotesUsedResolver(testCase)
             testCase.verifyEqual(registry.LinkResolvers{1}, mockResolver);
         end
 
+        function testReplaceRegisteredResolver(testCase)
+        % A library that reconfigures needs its new resolver to take
+        % effect. Without Replace the first registration wins; with it,
+        % the resolver for that prefix is swapped and keeps its position.
+
+            registry = openminds.internal.resolver.LinkResolverRegistry.instance();
+
+            firstResolver = ommtest.helper.mock.MockLinkResolver();
+            secondResolver = ommtest.helper.mock.MockLinkResolver();
+            openminds.registerLinkResolver(firstResolver);
+
+            openminds.registerLinkResolver(secondResolver);
+            registered = registry.getLinkResolver("https://mock.io/x");
+            testCase.verifyTrue(registered == firstResolver, ...
+                'Without Replace, the first registration should win.')
+
+            openminds.registerLinkResolver(secondResolver, "Replace", true);
+            registered = registry.getLinkResolver("https://mock.io/x");
+            testCase.verifyTrue(registered == secondResolver, ...
+                'With Replace, the new resolver should take over the prefix.')
+
+            testCase.verifyEqual( ...
+                sum(cellfun(@(r) isa(r, 'ommtest.helper.mock.MockLinkResolver'), ...
+                    registry.LinkResolvers)), 1, ...
+                'Replacing should not add a second resolver for the prefix.')
+        end
+
         function testNoDuplicateResolvers(testCase)
             % Test that duplicate resolvers are not added
             resolver = ommtest.helper.mock.MockLinkResolver();