[ADF-1312] form validation enhancements (#2180)

* validation api enhancements

- changing 'required' causes re-validation of the form
- get field by id

* allow binding field validators from html

* demo validator

* documentation updates

* fix after rebase

* markdown fixes

* markdown linter settings for workspace config (vs code)

* restore material theme

demo-shell-ng2/app/components/activiti/activiti-demo.component.html

@@ -68,6 +68,7 @@
                         <activiti-task-details #activitidetails
                             [debugMode]="true"
                             [taskId]="currentTaskId"
+                            [fieldValidators]="fieldValidators"
                             (formCompleted)="onFormCompleted($event)"
                             (formContentClicked)="onFormContentClick($event)"
                             (taskCreated)="onTaskCreated($event)"

demo-shell-ng2/app/components/activiti/activiti-demo.component.ts

@@ -15,10 +15,11 @@
  * limitations under the License.
  */
 
+// tslint:disable-next-line:adf-file-name
 import { AfterViewInit, Component, ElementRef, Input, OnDestroy, OnInit, ViewChild } from '@angular/core';
 import { ActivatedRoute, Router } from '@angular/router';
 import { AnalyticsReportListComponent } from 'ng2-activiti-analytics';
-import { FormEvent, FormFieldEvent, FormRenderingService, FormService } from 'ng2-activiti-form';
+import { FORM_FIELD_VALIDATORS, FormEvent, FormFieldEvent, FormRenderingService, FormService } from 'ng2-activiti-form';
 import {
     FilterProcessRepresentationModel,
     ProcessFiltersComponent,
@@ -43,6 +44,7 @@ import {
 } from 'ng2-alfresco-datatable';
 import { Subscription } from 'rxjs/Rx';
 import { /*CustomEditorComponent*/ CustomStencil01 } from './custom-editor/custom-editor.component';
+import { DemoFieldValidator } from './demo-field-validator';
 
 declare var componentHandler;
 
@@ -109,6 +111,11 @@ export class ActivitiDemoComponent implements AfterViewInit, OnDestroy, OnInit {
     dataTasks: ObjectDataTableAdapter;
     dataProcesses: ObjectDataTableAdapter;
 
+    fieldValidators = [
+        ...FORM_FIELD_VALIDATORS,
+        new DemoFieldValidator()
+    ];
+
     constructor(private elementRef: ElementRef,
                 private route: ActivatedRoute,
                 private router: Router,
@@ -141,11 +148,13 @@ export class ActivitiDemoComponent implements AfterViewInit, OnDestroy, OnInit {
             console.log(`Field value changed. Form: ${e.form.id}, Field: ${e.field.id}, Value: ${e.field.value}`);
         });
 
+        // Uncomment this block to see form event handling in action
+        /*
         formService.formEvents.subscribe((event: Event) => {
             console.log('Event fired:' + event.type);
             console.log('Event Target:' + event.target);
         });
-
+        */
     }
 
     ngOnInit() {

demo-shell-ng2/app/components/activiti/demo-field-validator.ts

@@ -0,0 +1,36 @@
+/*!
+ * @license
+ * Copyright 2016 Alfresco Software, Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { FormFieldModel, FormFieldTypes, FormFieldValidator } from 'ng2-activiti-form';
+
+export class DemoFieldValidator implements FormFieldValidator {
+
+    isSupported(field: FormFieldModel): boolean {
+        return field && field.type === FormFieldTypes.TEXT;
+    }
+
+    validate(field: FormFieldModel): boolean {
+        if (this.isSupported(field)) {
+            if (field.value && field.value.toLowerCase() === 'admin') {
+                field.validationSummary = 'Sorry, the value cannot be "admin".';
+                return false;
+            }
+        }
+        return true;
+    }
+
+}