add note on how to get an example keycloak setup for the example setup

For the configAttributeSlug the further validation fails ugly otherwise
and there's generally no need to do further validation, if a config
string is null.

Makefile

@@ -0,0 +1,7 @@
+verify:
+	mvn -f attribute-endpoints-provider verify
+
+clean:
+	mvn -f attribute-endpoints-provider clean
+
+.PHONY: verify clean

README.md

@@ -5,17 +5,25 @@ For this it will provide API endpoints for every configured attribute-group.
 The configuration of the provider is possible via an admin page.
 
 Every endpoint responds with a list of all attribute values, that:
- - is in the attribute group matching `attribute-group`
+- are in the attribute group matching `attribute-group`
- - matches an optional RegEx Pattern `attribute-regex`
+- match an optional RegEx Pattern `attribute-regex`
- - belongs to a user with a role matching `match-role`
+- belong to a user with a role matching `match-role`
- - is non-empty
+- are non-empty
 
 Multivalue attributes are flattened in the response.
 
+## Building
+
+Maven is required for building the provider.
+
+Once all dependencies are met, simply call `make` to build the provider, which should then produce a `attribute-endpoints-provider-1.0-SNAPSHOT.jar` in the `attribute-endpoints-provider/target/` directory.
+
+There's also `make clean` available for removing the output directory.
 
 ## Example Setup
 
-We assume an unconfigured, fresh Keycloak installation running under `http://localhost:8080`.
+We assume an unconfigured, fresh Keycloak installation running under `http://localhost:8080`.  
+(This can be achieved by running the provided `compose.yaml` after building the provider as outlined in [Building](#building).)
 
  1. Add a new realm  
     e.g. "TestRealm"
@@ -53,7 +61,7 @@ We assume an unconfigured, fresh Keycloak installation running under `http://loc
     - After creating:
       - give it the role `myattribute-export`
       - set a password in the users settings `Creadentials > Set password`. For Example `"password"`
-8. Under `🪪 Attribute Endpoints 🚀 > Create item`, add a new endpoint to the provider  
+8. Under `Attribute Endpoints > Create item`, add a new endpoint to the provider  
    Example:
    - `Slug` = `"ssh_keys"`
    - `Attribute Group` = `"my-attributes-group"`

attribute-endpoints-provider/src/main/java/de/ccc/hamburg/keycloak/attribute_endpoints/AdminUiPage.java

@@ -24,7 +24,7 @@ import com.google.auto.service.AutoService;
  */
 @AutoService(UiPageProviderFactory.class)
 public class AdminUiPage implements UiPageProvider, UiPageProviderFactory<ComponentModel> {
-    public static final String PROVIDER_ID = "🪪 Attribute Endpoints 🚀";
+    public static final String PROVIDER_ID = "Attribute Endpoints";
 
     @Override
     public void init(Config.Scope config) {
@@ -54,22 +54,28 @@ public class AdminUiPage implements UiPageProvider, UiPageProviderFactory<Compon
 
         Pattern slugPattern = Pattern.compile("^[a-zA-Z0-9_-]*$");
         String configAttributeSlug = model.getConfig().getFirst("slug");
-
+        if (configAttributeSlug == null) {
-        if (!slugPattern.matcher(configAttributeSlug).matches()) {
+            hasError = true;
+            errorString += " • [Slug] can not be empty\n";
+        } else if (!slugPattern.matcher(configAttributeSlug).matches()) {
             hasError = true;
             errorString += " • [Slug] can only contain anlphanumeric characters, dash and underscore (a-z A-Z 0-9 _ - )\n";
         }
 
         String configAuthRole = model.getConfig().getFirst("auth-role");
-        RoleModel authRole = realm.getRole(configAuthRole);
+        if (configAuthRole == null) {
-        if (authRole == null) {
+            hasError = true;
+            errorString += " • [Auth Role] can not be empty\n";
+        } else if (realm.getRole(configAuthRole) == null) {
             hasError = true;
             errorString += " • [Auth Role] does not exist\n";
         }
 
         String configMatchRole = model.getConfig().getFirst("match-role");
-        RoleModel matchRole = realm.getRole(configMatchRole);
+        if (configMatchRole == null) {
-        if (matchRole == null) {
+            hasError = true;
+            errorString += " • [Match Role] can not be empty\n";
+        } else if (realm.getRole(configMatchRole) == null) {
             hasError = true;
             errorString += " • [Match Role] does not exist\n";
         }
@@ -77,7 +83,10 @@ public class AdminUiPage implements UiPageProvider, UiPageProviderFactory<Compon
         UserProfileProvider profileProvider = session.getProvider(UserProfileProvider.class);
         UPConfig upconfig = profileProvider.getConfiguration();
         String configAttributeGroup = model.getConfig().getFirst("attribute-group");
-        if (!upconfig.getGroups().stream().anyMatch(g -> g.getName().equals(configAttributeGroup))) {
+        if (configAttributeGroup == null) {
+            hasError = true;
+            errorString += " • [Attribute Group] can not be empty\n";
+        } else if (!upconfig.getGroups().stream().anyMatch(g -> g.getName().equals(configAttributeGroup))) {
             hasError = true;
             errorString += " • [Attribute Group] does not exist\n";
         }

attribute-endpoints-provider/src/main/java/de/ccc/hamburg/keycloak/attribute_endpoints/AttributeEndpointsResourceProvider.java

@@ -53,7 +53,7 @@ public class AttributeEndpointsResourceProvider implements RealmResourceProvider
     @GET
     @Path("export/{slug}")
     @Produces(MediaType.APPLICATION_JSON)
-    public Response exportKeys(@PathParam("slug") String slug) {
+    public Response exportAttributeValues(@PathParam("slug") String slug) {
         KeycloakContext context = session.getContext();
         RealmModel realm = context.getRealm();
 
@@ -62,11 +62,16 @@ public class AttributeEndpointsResourceProvider implements RealmResourceProvider
                 .filter(c -> c.getConfig().getFirst("slug").equals(slug))
                 .toList();
 
+        Auth auth = AttributeEndpointsResourceProvider.getAuth(session);
+
         if (componentList.isEmpty()) {
             throw new NotFoundException("Endpoint not found.");
         }
 
-        Auth auth = AttributeEndpointsResourceProvider.getAuth(session);
+        if (componentList.size() > 1) {
+            throw new NotFoundException(
+                    "Endpoint Configuration Error - Multiple configurations exist for this endpoint.");
+        }
 
         ComponentModel component = componentList.get(0);
 
@@ -106,11 +111,6 @@ public class AttributeEndpointsResourceProvider implements RealmResourceProvider
             throw new ForbiddenException("User does not have required auth role.");
         }
 
-        if (componentList.size() > 1) {
-            throw new NotFoundException(
-                    "Endpoint Configuration Error - Multiple configurations exist for this endpoint.");
-        }
-
         List<String> attributeNames = upconfig.getAttributes()
                 .stream()
                 .filter(a -> a.getGroup() != null && a.getGroup().equals(configAttributeGroup))