Set Error State Matcher from Control Model

Author: jcroll

README.md

@@ -1071,6 +1071,17 @@ export const DEFAULT_ERROR_STATE_MATCHER: DynamicErrorMessagesMatcher =
     };
 ```
 
+You can also set an error matcher on a per control basis by assigning it under the `additional` field:
+```ts
+new DynamicInputModel({
+    id: "sampleInput",
+    label: "Sample Input",
+    additional: {
+        errorStateMatcher: myCustomErrorMessagesMatcher
+    }
+})
+```
+
 Please note here that NG Dynamic Forms always assumes both the control being invalid and error messages being defined on the model 
 as a fixed precondition.
 

projects/ng-dynamic-forms/core/src/lib/service/dynamic-form-validation.service.ts

@@ -136,14 +136,18 @@ export class DynamicFormValidationService {
         control.updateValueAndValidity();
     }
 
-    showErrorMessages(control: AbstractControl, model: DynamicFormControlModel, hasFocus: boolean): boolean {
-
-        const precondition = control.invalid && model.hasErrorMessages;
-        const matcher = this._DYNAMIC_ERROR_MESSAGES_MATCHER ? this._DYNAMIC_ERROR_MESSAGES_MATCHER(control, model, hasFocus) :
-            DEFAULT_ERROR_STATE_MATCHER(control, model, hasFocus);
-
-        return precondition && matcher;
-    }
+  showErrorMessages(control: AbstractControl, model: DynamicFormControlModel, hasFocus: boolean): boolean {
+    const precondition = control.invalid && model.hasErrorMessages;
+
+    const matcher =
+      typeof model["getAdditional"] !== undefined && model["getAdditional"]("errorStateMatcher")
+        ? model["getAdditional"]("errorStateMatcher")
+        : this._DYNAMIC_ERROR_MESSAGES_MATCHER
+        ? this._DYNAMIC_ERROR_MESSAGES_MATCHER
+        : DEFAULT_ERROR_STATE_MATCHER;
+
+    return precondition && matcher(control, model, hasFocus);
+  }
 
     parseErrorMessageConfig(template: string, model: DynamicFormControlModel, error: any = null): string {