support custom schema validation error messages

* Closes inveniosoftware-contrib#417

Author: harunurhan

example/app/app.config.ts

@@ -98,6 +98,17 @@ export class AppConfig {
               }
             }
           }
+        },
+        imprints: {
+          items: {
+            properties: {
+              date: {
+                errorMessage: {
+                  format: 'This is not a date!'
+                }
+              }
+            }
+          }
         }
       }
     },

package.json

@@ -43,7 +43,8 @@
     "zone.js": "^0.8.4"
   },
   "dependencies": {
-    "ajv": "^4.11.3",
+    "ajv": "^5.0.0",
+    "ajv-errors": "^1.0.0",
     "diff": "^3.3.0",
     "immutable": "^3.8.1",
     "katex": "^0.7.1",

src/shared/interfaces/custom-error-messages.ts

@@ -0,0 +1,20 @@
+export interface CustomErrorMessages {
+  pattern?: string;
+  format?: string;
+  multipleOf?: string;
+  maximum?: string;
+  exclusiveMaximum?: string;
+  minimum?: string;
+  exclusiveMinimum?: string;
+
+  /**
+   * Schema validation for pritimive types so below is not supported yet
+   *  maxLength?: string;
+   *  minLength?: string;
+   *  maxItems?: string;
+   *  minItems?: string;
+   *  uniqueItems?: string;
+   *  maxProperties?: string;
+   *  minProperties?: string;
+   */
+}

src/shared/interfaces/index.ts

@@ -27,3 +27,4 @@ export { CustomFormatValidation } from './custom-format-validation';
 export { JsonPatchesByPath } from './json-patches-by-path';
 export { ViewTemplateConfig } from './view-template-config';
 export { ShortcutActionFunction } from './shortcut-action-function';
+export { CustomErrorMessages } from './custom-error-messages';

src/shared/interfaces/schema-option.ts

@@ -3,6 +3,7 @@ import { LongListNavigatorConfig } from './long-list-navigator-config';
 import { ViewTemplateConfig } from './view-template-config';
 import { RefConfig } from './ref-config';
 import { OnValueChangeFunction } from './on-value-change-function';
+import { CustomErrorMessages } from './custom-error-messages';
 
 export interface SchemaOption {
   /**
@@ -109,4 +110,9 @@ export interface SchemaOption {
    * Flag to enable LaTeX preview in a field.
    */
   latexPreviewEnabled?: boolean;
+
+  /**
+   * Custom error messages for schema validation
+   */
+  errorMessage?: string | CustomErrorMessages;
 }

src/shared/services/schema-validation.service.ts

@@ -22,14 +22,16 @@
 
 import { Injectable } from '@angular/core';
 import * as Ajv from 'ajv';
-import { AppGlobalsService } from './app-globals.service';
+import * as enableCustomErrorMessages from 'ajv-errors';
 
+import { AppGlobalsService } from './app-globals.service';
 import { JSONSchema, ValidationError } from '../interfaces';
 
 @Injectable()
 export class SchemaValidationService {
 
-  private ajv = new Ajv({ allErrors: true });
+  // `jsonPointer: true` is required for `avj-errors` package
+  private ajv = new Ajv({ allErrors: true, jsonPointers: true });
 
   // https://gist.github.com/dperini/729294
   private reWebUrl = new RegExp(
@@ -72,6 +74,8 @@ export class SchemaValidationService {
   );
 
   constructor(public appGlobalsService: AppGlobalsService) {
+    enableCustomErrorMessages(this.ajv);
+
     //  ajv didn't support format:url, so was added using web url regex for validation
     this.ajv.addFormat('url', this.reWebUrl);
     if (this.appGlobalsService.config && this.appGlobalsService.config.customFormatValidation) {