Improve markdown component

ui-ngx/src/app/core/services/dynamic-component-factory.service.ts

@@ -23,10 +23,12 @@ import {
   NgModule,
   NgModuleRef,
   OnDestroy,
-  Type
+  Type,
+  ɵresetCompiledComponents
 } from '@angular/core';
-import { Observable, ReplaySubject } from 'rxjs';
+import { from, Observable } from 'rxjs';
 import { CommonModule } from '@angular/common';
+import { catchError, map, mergeMap } from 'rxjs/operators';
 
 @NgModule()
 export abstract class DynamicComponentModule implements OnDestroy {
@@ -56,10 +58,10 @@ export class DynamicComponentFactoryService {
                      componentType: Type<T>,
                      template: string,
                      modules?: Type<any>[],
-                     preserveWhitespaces?: boolean): Observable<ComponentFactory<T>> {
-    const dymamicComponentFactorySubject = new ReplaySubject<ComponentFactory<T>>();
-    import('@angular/compiler').then(
-      () => {
+                     preserveWhitespaces?: boolean,
+                     compileAttempt = 1): Observable<ComponentFactory<T>> {
+    return from(import('@angular/compiler')).pipe(
+      mergeMap(() => {
         const comp = this.createDynamicComponent(componentType, template, preserveWhitespaces);
         let moduleImports: Type<any>[] = [CommonModule];
         if (modules) {
@@ -70,29 +72,33 @@ export class DynamicComponentFactoryService {
           declarations: [comp],
           imports: moduleImports
         })(class DynamicComponentInstanceModule extends DynamicComponentModule {});
-        try {
-          this.compiler.compileModuleAsync(dynamicComponentInstanceModule).then(
-            (module) => {
-              const moduleRef = module.create(this.injector);
-              const factory = moduleRef.componentFactoryResolver.resolveComponentFactory(comp);
-              this.dynamicComponentModulesMap.set(factory, {
-                moduleRef,
-                moduleType: module.moduleType
-              });
-              dymamicComponentFactorySubject.next(factory);
-              dymamicComponentFactorySubject.complete();
+        return from(this.compiler.compileModuleAsync(dynamicComponentInstanceModule)).pipe(
+          map((module) => {
+            let moduleRef: NgModuleRef<any>;
+            try {
+              moduleRef = module.create(this.injector);
+            } catch (e) {
+              this.compiler.clearCacheFor(module.moduleType);
+              throw e;
             }
-          ).catch(
-            (e) => {
-              dymamicComponentFactorySubject.error(e);
+            const factory = moduleRef.componentFactoryResolver.resolveComponentFactory(comp);
+            this.dynamicComponentModulesMap.set(factory, {
+              moduleRef,
+              moduleType: module.moduleType
+            });
+            return factory;
+          }),
+          catchError((error) => {
+            if (compileAttempt === 1) {
+              ɵresetCompiledComponents();
+              return this.createDynamicComponentFactory(componentType, template, modules, preserveWhitespaces, ++compileAttempt);
+            } else {
+              throw error;
             }
-          );
-        } catch (e) {
-          dymamicComponentFactorySubject.error(e);
-        }
-      }
+          })
+        );
+      })
     );
-    return dymamicComponentFactorySubject.asObservable();
   }
 
   public destroyDynamicComponentFactory<T>(factory: ComponentFactory<T>) {

ui-ngx/src/app/shared/components/markdown.component.html

@@ -1,21 +0,0 @@
-<!--
-
-    Copyright © 2016-2021 The Thingsboard Authors
-
-    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.
-
--->
-<ng-container #markdownContainer>
-  <markdown *ngIf="!isMarkdownReady" #markdownComponent [data]="data"
-            [lineNumbers]="lineNumbers" (ready)="onMarkdownReady()"></markdown>
-</ng-container>

ui-ngx/src/app/shared/components/markdown.component.scss

@@ -1,20 +0,0 @@
-/**
- * Copyright © 2016-2021 The Thingsboard Authors
- *
- * 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.
- */
-:host {
-  markdown {
-    display: none;
-  }
-}

ui-ngx/src/app/shared/components/markdown.component.ts

@@ -15,6 +15,7 @@
 ///
 
 import {
+  ChangeDetectorRef,
   Component,
   ComponentFactory,
   ComponentRef,
@@ -22,38 +23,31 @@ import {
   Inject,
   Injector,
   Input, OnChanges,
-  OnDestroy,
-  OnInit,
   Output,
-  Renderer2, SimpleChanges,
-  Type,
-  ViewChild,
+  SimpleChanges,
+  Type, ViewChild,
   ViewContainerRef
 } from '@angular/core';
 import { HelpService } from '@core/services/help.service';
-import { MarkdownComponent } from 'ngx-markdown';
+import { MarkdownService, PrismPlugin } from 'ngx-markdown';
 import { DynamicComponentFactoryService } from '@core/services/dynamic-component-factory.service';
 import { coerceBooleanProperty } from '@angular/cdk/coercion';
 import { SHARED_MODULE_TOKEN } from '@shared/components/tokens';
 
 @Component({
   selector: 'tb-markdown',
-  templateUrl: './markdown.component.html',
-  styleUrls: ['./markdown.component.scss']
+  template: '<ng-container #markdownContainer>' +
+            '</ng-container>' +
+            '<div *ngIf="error" style="color: #f00; font-size: 14px;' +
+                                      ' line-height: 28px;' +
+                                      ' background: #efefef;">' +
+                      '{{error}}' +
+            '</div>'
 })
-export class TbMarkdownComponent implements OnDestroy, OnInit, OnChanges {
-
-  private markdownComponent: MarkdownComponent;
+export class TbMarkdownComponent implements OnChanges {
 
   @ViewChild('markdownContainer', {read: ViewContainerRef, static: true}) markdownContainer: ViewContainerRef;
 
-  @ViewChild('markdownComponent', {static: false}) set content(content: MarkdownComponent) {
-      this.markdownComponent = content;
-      if (this.isMarkdownReady && this.markdownComponent) {
-        this.processMarkdownComponent();
-      }
-  }
-
   @Input() data: string | undefined;
 
   @Input() markdownClass: string | undefined;
@@ -70,35 +64,25 @@ export class TbMarkdownComponent implements OnDestroy, OnInit, OnChanges {
 
   isMarkdownReady = false;
 
+  error = null;
+
   private tbMarkdownInstanceComponentRef: ComponentRef<any>;
   private tbMarkdownInstanceComponentFactory: ComponentFactory<any>;
 
   constructor(private help: HelpService,
-              private renderer: Renderer2,
+              private cd: ChangeDetectorRef,
+              public markdownService: MarkdownService,
               @Inject(SHARED_MODULE_TOKEN) private sharedModule: Type<any>,
               private dynamicComponentFactoryService: DynamicComponentFactoryService) {}
 
-  ngOnInit(): void {
-  }
-
-  ngOnDestroy(): void {
-  }
-
   ngOnChanges(changes: SimpleChanges): void {
-    for (const propName of Object.keys(changes)) {
-      const change = changes[propName];
-      if (!change.firstChange && change.currentValue !== change.previousValue) {
-        if (propName === 'data') {
-          if (this.data) {
-            this.isMarkdownReady = false;
-          }
-        }
-      }
+    if (this.data) {
+      this.render(this.data);
     }
   }
 
-  private processMarkdownComponent() {
-    let template = this.markdownComponent.element.nativeElement.innerHTML;
+  private render(markdown: string) {
+    let template = this.markdownService.compile(markdown, false);
     template = this.sanitizeCurlyBraces(template);
     let markdownClass = 'tb-markdown-view';
     if (this.markdownClass) {
@@ -106,7 +90,6 @@ export class TbMarkdownComponent implements OnDestroy, OnInit, OnChanges {
     }
     template = `<div [ngStyle]="style" class="${markdownClass}">${template}</div>`;
     this.markdownContainer.clear();
-    this.markdownComponent = null;
     const parent = this;
     this.dynamicComponentFactoryService.createDynamicComponentFactory(
       class TbMarkdownInstance {
@@ -124,13 +107,38 @@ export class TbMarkdownComponent implements OnDestroy, OnInit, OnChanges {
         this.tbMarkdownInstanceComponentRef =
           this.markdownContainer.createComponent(this.tbMarkdownInstanceComponentFactory, 0, injector);
         this.tbMarkdownInstanceComponentRef.instance.style = this.style;
-      } catch (e) {
+        this.handlePlugins(this.tbMarkdownInstanceComponentRef.location.nativeElement);
+        this.markdownService.highlight(this.tbMarkdownInstanceComponentRef.location.nativeElement);
+        this.error = null;
+      } catch (error) {
+        this.error = (error ? error + '' : 'Failed to render markdown!').replace(/\n/g, '<br>');
         this.destroyMarkdownInstanceResources();
       }
+      this.cd.detectChanges();
+      this.ready.emit();
+    },
+    (error) => {
+      this.error = (error ? error + '' : 'Failed to render markdown!').replace(/\n/g, '<br>');
+      this.destroyMarkdownInstanceResources();
+      this.cd.detectChanges();
       this.ready.emit();
     });
   }
 
+  private handlePlugins(element: HTMLElement): void {
+    if (this.lineNumbers) {
+      this.setPluginClass(element, PrismPlugin.LineNumbers);
+    }
+  }
+
+  private setPluginClass(element: HTMLElement, plugin: string | string[]): void {
+    const preElements = element.querySelectorAll('pre');
+    for (let i = 0; i < preElements.length; i++) {
+      const classes = plugin instanceof Array ? plugin : [plugin];
+      preElements.item(i).classList.add(...classes);
+    }
+  }
+
   private sanitizeCurlyBraces(template: string): string {
     return template.replace(/{/g, '&#123;').replace(/}/g, '&#125;');
   }
@@ -142,13 +150,4 @@ export class TbMarkdownComponent implements OnDestroy, OnInit, OnChanges {
     }
     this.tbMarkdownInstanceComponentRef = null;
   }
-
-  onMarkdownReady() {
-    if (this.data) {
-      this.isMarkdownReady = true;
-      if (this.markdownComponent) {
-        this.processMarkdownComponent();
-      }
-    }
-  }
 }

ui-ngx/src/styles.scss

@@ -516,12 +516,12 @@ mat-label {
   }
 
   p, div {
-    padding-right: 32px;
     color: rgba(15, 22, 29, 0.8);
     line-height: 1.5em;
   }
 
-  p, div {
+  & > p, & > div {
+    padding-right: 32px;
     padding-left: 32px;
   }