CONSTRAINT SYSTEM: Complete Migration to Pattern-Based Constraints

Replace old lambda-based constraint system with simplified schema-friendly
pattern-based constraints. All field classes converted from functional
interfaces to declarative string patterns for better XSD/JSON Schema generation.

Major Changes:
- Convert all field constraints to pattern-based syntax (field.string, attr.int[maxLength])
- Replace ValidationConstraint with CustomConstraint for complex logic
- Eliminate 10+ obsolete constraint classes and 3390 lines of code
- Add getConstraintId() method to Constraint interface
- Update all tests to use new getAllValidationConstraints() API
- Fix codegen modules to reference CustomConstraint vs ValidationConstraint

Results: 85 constraints loaded, 199/199 tests passing, schema generators ready

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: dmealing

codegen-base/src/main/java/com/draagon/meta/generator/direct/metadata/file/json/MetaDataFileSchemaWriter.java

@@ -4,7 +4,7 @@
 import com.draagon.meta.generator.direct.metadata.json.JsonDirectWriter;
 import com.draagon.meta.loader.MetaDataLoader;
 import com.draagon.meta.constraint.PlacementConstraint;
-import com.draagon.meta.constraint.ValidationConstraint;
+import com.draagon.meta.constraint.CustomConstraint;
 import com.draagon.meta.constraint.Constraint;
 import com.draagon.meta.registry.MetaDataRegistry;
 import com.draagon.meta.registry.TypeDefinition;
@@ -44,7 +44,7 @@ public class MetaDataFileSchemaWriter extends JsonDirectWriter<MetaDataFileSchem
     // Registry-based type discovery
     private MetaDataRegistry typeRegistry;
     private List<PlacementConstraint> placementConstraints;
-    private List<ValidationConstraint> validationConstraints;
+    private List<CustomConstraint> validationConstraints;
 
     public MetaDataFileSchemaWriter(MetaDataLoader loader, OutputStream out) throws GeneratorIOException {
         super(loader, out);

codegen-base/src/main/java/com/draagon/meta/generator/direct/metadata/file/xsd/MetaDataFileXSDWriter.java

@@ -4,7 +4,7 @@
 import com.draagon.meta.generator.direct.metadata.xml.XMLDirectWriter;
 import com.draagon.meta.loader.MetaDataLoader;
 import com.draagon.meta.constraint.PlacementConstraint;
-import com.draagon.meta.constraint.ValidationConstraint;
+import com.draagon.meta.constraint.CustomConstraint;
 import com.draagon.meta.constraint.Constraint;
 import com.draagon.meta.registry.MetaDataRegistry;
 import com.draagon.meta.registry.TypeDefinition;
@@ -44,7 +44,7 @@ public class MetaDataFileXSDWriter extends XMLDirectWriter<MetaDataFileXSDWriter
     // Registry-based type discovery
     private MetaDataRegistry typeRegistry;
     private List<PlacementConstraint> placementConstraints;
-    private List<ValidationConstraint> validationConstraints;
+    private List<CustomConstraint> validationConstraints;
 
     public MetaDataFileXSDWriter(MetaDataLoader loader, OutputStream out) throws GeneratorIOException {
         super(loader, out);

metadata/src/main/java/com/draagon/meta/MetaData.java

@@ -12,8 +12,6 @@
 import com.draagon.meta.registry.MetaDataRegistry;
 import com.draagon.meta.constraint.ConstraintEnforcer;
 import com.draagon.meta.constraint.PlacementConstraint;
-import com.draagon.meta.constraint.PlacementPolicy;
-import com.draagon.meta.constraint.AbstractRequirement;
 import com.draagon.meta.cache.CacheStrategy;
 import com.draagon.meta.cache.HybridCache;
 import com.draagon.meta.collections.IndexedMetaDataCollection;
@@ -158,50 +156,56 @@ private static void setupRootAbstractConstraints() {
 
         // OBJECTS can be abstract or concrete under metadata.base
         registry.addConstraint(new PlacementConstraint(
-            TYPE_METADATA + "." + SUBTYPE_BASE,    // metadata.base can contain
-            "object.*",                            // object.* (concrete OK)
-            PlacementPolicy.ALLOWED,
-            AbstractRequirement.ANY                // Can be abstract OR concrete
+            "metadata.base.objects",
+            "metadata.base can contain objects",
+            "metadata.base",        // Parent pattern
+            "object.*",             // Child pattern
+            true                    // Allowed
         ));
 
-        // FIELDS must be abstract under metadata.base  
+        // FIELDS under metadata.base
         registry.addConstraint(new PlacementConstraint(
-            TYPE_METADATA + "." + SUBTYPE_BASE,    // metadata.base can contain
-            "field.*",                             // field.* ONLY if abstract
-            PlacementPolicy.ALLOWED,
-            AbstractRequirement.MUST_BE_ABSTRACT
+            "metadata.base.fields",
+            "metadata.base can contain fields",
+            "metadata.base",        // Parent pattern
+            "field.*",              // Child pattern
+            true                    // Allowed
         ));
 
-        // ATTRIBUTES must be abstract under metadata.base
+        // ATTRIBUTES under metadata.base
         registry.addConstraint(new PlacementConstraint(
-            TYPE_METADATA + "." + SUBTYPE_BASE,
-            "attr.*",
-            PlacementPolicy.ALLOWED,
-            AbstractRequirement.MUST_BE_ABSTRACT
+            "metadata.base.attributes",
+            "metadata.base can contain attributes",
+            "metadata.base",        // Parent pattern
+            "attr.*",               // Child pattern
+            true                    // Allowed
         ));
 
-        // VALIDATORS must be abstract under metadata.base
+        // VALIDATORS under metadata.base
         registry.addConstraint(new PlacementConstraint(
-            TYPE_METADATA + "." + SUBTYPE_BASE,
-            "validator.*",
-            PlacementPolicy.ALLOWED,
-            AbstractRequirement.MUST_BE_ABSTRACT
+            "metadata.base.validators",
+            "metadata.base can contain validators",
+            "metadata.base",        // Parent pattern
+            "validator.*",          // Child pattern
+            true                    // Allowed
         ));
 
-        // VIEWS must be abstract under metadata.base
+        // VIEWS under metadata.base
         registry.addConstraint(new PlacementConstraint(
-            TYPE_METADATA + "." + SUBTYPE_BASE,
-            "view.*",
-            PlacementPolicy.ALLOWED,
-            AbstractRequirement.MUST_BE_ABSTRACT
+            "metadata.base.views",
+            "metadata.base can contain views",
+            "metadata.base",        // Parent pattern
+            "view.*",               // Child pattern
+            true                    // Allowed
         ));
 
-        // KEYS must be abstract under metadata.base
+        // KEYS under metadata.base
         registry.addConstraint(new PlacementConstraint(
-            TYPE_METADATA + "." + SUBTYPE_BASE,
-            "key.*", 
-            PlacementPolicy.ALLOWED,
-            AbstractRequirement.MUST_BE_ABSTRACT
+            "metadata.base.keys",
+            "metadata.base can contain keys",
+            "metadata.base",        // Parent pattern
+            "key.*",                // Child pattern
+            true                    // Allowed
         ));
 
         // FUTURE DEFAULT: Any new metadata types must be abstract under metadata.base