MOBILE-3323 editor: Store editor original content to detect changes

Author: dpalou

src/core/editor/components/rich-text-editor/rich-text-editor.ts

@@ -103,6 +103,7 @@ export class CoreEditorRichTextEditorComponent implements AfterContentInit, OnDe
     protected hideMessageTimeout: NodeJS.Timer;
     protected lastDraft = '';
     protected draftWasRestored = false;
+    protected originalContent: string;
 
     constructor(
             protected domUtils: CoreDomUtilsProvider,
@@ -133,6 +134,8 @@ export class CoreEditorRichTextEditorComponent implements AfterContentInit, OnDe
         // Setup the editor.
         this.editorElement = this.editor.nativeElement as HTMLDivElement;
         this.setContent(this.control.value);
+        this.originalContent = this.control.value;
+        this.lastDraft = this.control.value;
         this.editorElement.onchange = this.onChange.bind(this);
         this.editorElement.onkeyup = this.onChange.bind(this);
         this.editorElement.onpaste = this.onChange.bind(this);
@@ -141,8 +144,19 @@ export class CoreEditorRichTextEditorComponent implements AfterContentInit, OnDe
 
         // Listen for changes on the control to update the editor (if it is updated from outside of this component).
         this.valueChangeSubscription = this.control.valueChanges.subscribe((param) => {
-            if (!this.draftWasRestored) {
+            if (!this.draftWasRestored || this.originalContent != param) {
+                // Apply the new content.
                 this.setContent(param);
+                this.originalContent = param;
+                this.infoMessage = null;
+
+                // Save a draft so the original content is saved.
+                this.lastDraft = param;
+                this.editorOffline.saveDraft(this.contextLevel, this.contextInstanceId, this.elementId,
+                        this.draftExtraParams, this.pageInstance, param, param);
+            } else {
+                // A draft was restored and the content hasn't changed in the site. Use the draft value instead of this one.
+                this.control.setValue(this.lastDraft, {emitEvent: false});
             }
         });
 
@@ -740,14 +754,16 @@ export class CoreEditorRichTextEditorComponent implements AfterContentInit, OnDe
      */
     protected async restoreDraft(): Promise<void> {
         try {
-            let draftText = await this.editorOffline.resumeDraft(this.contextLevel, this.contextInstanceId, this.elementId,
-                    this.draftExtraParams, this.pageInstance);
+            const entry = await this.editorOffline.resumeDraft(this.contextLevel, this.contextInstanceId, this.elementId,
+                    this.draftExtraParams, this.pageInstance, this.originalContent);
 
-            if (typeof draftText == 'undefined') {
+            if (typeof entry == 'undefined') {
                 // No draft found.
                 return;
             }
 
+            let draftText = entry.drafttext;
+
             // Revert untouched editor contents to an empty string.
             if (draftText == '<p></p>' || draftText == '<p><br></p>' || draftText == '<br>' ||
                     draftText == '<p>&nbsp;</p>' || draftText == '<p><br>&nbsp;</p>') {
@@ -760,9 +776,12 @@ export class CoreEditorRichTextEditorComponent implements AfterContentInit, OnDe
                 this.setContent(draftText);
                 this.lastDraft = draftText;
                 this.draftWasRestored = true;
+                this.originalContent = entry.originalcontent;
 
-                // Notify the user.
-                this.showMessage('core.editor.textrecovered', this.RESTORE_MESSAGE_CLEAR_TIME);
+                if (entry.drafttext != entry.originalcontent) {
+                    // Notify the user.
+                    this.showMessage('core.editor.textrecovered', this.RESTORE_MESSAGE_CLEAR_TIME);
+                }
             }
         } catch (error) {
             // Ignore errors, shouldn't happen.
@@ -783,7 +802,7 @@ export class CoreEditorRichTextEditorComponent implements AfterContentInit, OnDe
 
             try {
                 await this.editorOffline.saveDraft(this.contextLevel, this.contextInstanceId, this.elementId,
-                        this.draftExtraParams, this.pageInstance, newText);
+                        this.draftExtraParams, this.pageInstance, newText, this.originalContent);
 
                 // Draft saved, notify the user.
                 this.lastDraft = newText;

src/core/editor/providers/editor-offline.ts

@@ -53,25 +53,29 @@ export class CoreEditorOfflineProvider {
                     {
                         name: 'drafttext',
                         type: 'TEXT',
-                        notNull: true
+                        notNull: true,
                     },
                     {
                         name: 'pageinstance',
                         type: 'TEXT',
-                        notNull: true
+                        notNull: true,
                     },
                     {
                         name: 'timecreated',
                         type: 'INTEGER',
-                        notNull: true
+                        notNull: true,
                     },
                     {
                         name: 'timemodified',
                         type: 'INTEGER',
-                        notNull: true
+                        notNull: true,
+                    },
+                    {
+                        name: 'originalcontent',
+                        type: 'TEXT',
                     },
                 ],
-                primaryKeys: ['contextlevel', 'contextinstanceid', 'elementid', 'extraparams']
+                primaryKeys: ['contextlevel', 'contextinstanceid', 'elementid', 'extraparams'],
             },
         ],
     };
@@ -158,11 +162,12 @@ export class CoreEditorOfflineProvider {
      * @param elementId Element ID.
      * @param extraParams Object with extra params to identify the draft.
      * @param pageInstance Unique identifier to prevent storing data from several sources at the same time.
+     * @param originalContent Original content of the editor.
      * @param siteId Site ID. If not defined, current site.
-     * @return Promise resolved with the draft text. Undefined if no draft stored.
+     * @return Promise resolved with the draft data. Undefined if no draft stored.
      */
     async resumeDraft(contextLevel: string, contextInstanceId: number, elementId: string, extraParams: {[name: string]: any},
-            pageInstance: string, siteId?: string): Promise<string> {
+            pageInstance: string, originalContent?: string, siteId?: string): Promise<CoreEditorDraft> {
 
         try {
             // Check if there is a draft stored.
@@ -175,15 +180,21 @@ export class CoreEditorOfflineProvider {
                 entry.pageinstance = pageInstance;
                 entry.timemodified = Date.now();
 
+                if (originalContent && entry.originalcontent != originalContent) {
+                    entry.originalcontent = originalContent;
+                    entry.drafttext = ''; // "Discard" the draft.
+                }
+
                 await db.insertRecord(this.DRAFT_TABLE, entry);
             } catch (error) {
                 // Ignore errors saving the draft. It shouldn't happen.
             }
 
-            return entry.drafttext;
+            return entry;
         } catch (error) {
             // No draft stored. Store an empty draft to save the pageinstance.
-            await this.saveDraft(contextLevel, contextInstanceId, elementId, extraParams, pageInstance, '', siteId);
+            await this.saveDraft(contextLevel, contextInstanceId, elementId, extraParams, pageInstance, '', originalContent,
+                    siteId);
         }
     }
 
@@ -196,11 +207,12 @@ export class CoreEditorOfflineProvider {
      * @param extraParams Object with extra params to identify the draft.
      * @param pageInstance Unique identifier to prevent storing data from several sources at the same time.
      * @param draftText The text to store.
+     * @param originalContent Original content of the editor.
      * @param siteId Site ID. If not defined, current site.
      * @return Promise resolved when done.
      */
     async saveDraft(contextLevel: string, contextInstanceId: number, elementId: string, extraParams: {[name: string]: any},
-            pageInstance: string, draftText: string, siteId?: string): Promise<void> {
+            pageInstance: string, draftText: string, originalContent?: string, siteId?: string): Promise<void> {
 
         let timecreated = Date.now();
         let entry: CoreEditorDraft;
@@ -214,10 +226,17 @@ export class CoreEditorOfflineProvider {
             // No draft already stored.
         }
 
-        if (entry && entry.pageinstance != pageInstance) {
-            this.logger.warning(`Discarding draft because of pageinstance. Context '${contextLevel}' '${contextInstanceId}', ` +
-                    `element '${elementId}'`);
-            throw null;
+        if (entry) {
+            if (entry.pageinstance != pageInstance) {
+                this.logger.warning(`Discarding draft because of pageinstance. Context '${contextLevel}' '${contextInstanceId}', ` +
+                        `element '${elementId}'`);
+                throw null;
+            }
+
+            if (!originalContent) {
+                // Original content not set, use the one in the entry.
+                originalContent = entry.originalcontent;
+            }
         }
 
         const db = await this.sitesProvider.getSiteDb(siteId);
@@ -228,6 +247,9 @@ export class CoreEditorOfflineProvider {
         data.pageinstance = pageInstance;
         data.timecreated = timecreated;
         data.timemodified = Date.now();
+        if (originalContent) {
+            data.originalcontent = originalContent;
+        }
 
         await db.insertRecord(this.DRAFT_TABLE, data);
     }
@@ -251,4 +273,5 @@ type CoreEditorDraft = CoreEditorDraftPrimaryData & {
     pageinstance?: string; // Unique identifier to prevent storing data from several sources at the same time.
     timecreated?: number; // Time created.
     timemodified?: number; // Time modified.
+    originalcontent?: string; // Original content of the editor.
 };