Add wizard navigation validator (#1587)

src/sql/platform/dialog/dialogTypes.ts

@@ -139,6 +139,7 @@ export class Wizard {
 	public readonly onPageAdded = this._pageAddedEmitter.event;
 	private _pageRemovedEmitter = new Emitter<WizardPage>();
 	public readonly onPageRemoved = this._pageRemovedEmitter.event;
+	private _navigationValidator: (pageChangeInfo: sqlops.window.modelviewdialog.WizardPageChangeInfo) => boolean | Thenable<boolean>;
 
 	constructor(public title: string) { }
 
@@ -191,4 +192,19 @@ export class Wizard {
 		this.pages.splice(index, 1);
 		this._pageRemovedEmitter.fire(removedPage);
 	}
+
+	public registerNavigationValidator(validator: (pageChangeInfo: sqlops.window.modelviewdialog.WizardPageChangeInfo) => boolean | Thenable<boolean>): void {
+		this._navigationValidator = validator;
+	}
+
+	public validateNavigation(newPage: number): Thenable<boolean> {
+		if (this._navigationValidator) {
+			return Promise.resolve(this._navigationValidator({
+				lastPage: this._currentPage,
+				newPage: newPage
+			}));
+		} else {
+			return Promise.resolve(true);
+		}
+	}
 }

src/sql/platform/dialog/wizardModal.ts

@@ -106,12 +106,12 @@ export class WizardModal extends Modal {
 		});
 		this._wizard.onPageAdded(page => {
 			this.registerPage(page);
-			this.showPage(this.getCurrentPage());
+			this.showPage(this.getCurrentPage(), false);
 		});
 		this._wizard.onPageRemoved(page => {
 			let dialogPane = this._dialogPanes.get(page);
 			this._dialogPanes.delete(page);
-			this.showPage(this.getCurrentPage());
+			this.showPage(this.getCurrentPage(), false);
 			dialogPane.dispose();
 		});
 	}
@@ -123,10 +123,13 @@ export class WizardModal extends Modal {
 		page.onUpdate(() => this.setButtonsForPage(this._wizard.currentPage));
 	}
 
-	private showPage(index: number): void {
+	private async showPage(index: number, validate: boolean = true): Promise<void> {
 		let pageToShow = this._wizard.pages[index];
 		if (!pageToShow) {
-			this.done();
+			this.done(validate);
+			return;
+		}
+		if (validate && !await this._wizard.validateNavigation(index)) {
 			return;
 		}
 		this._dialogPanes.forEach((dialogPane, page) => {
@@ -163,12 +166,15 @@ export class WizardModal extends Modal {
 	}
 
 	public open(): void {
-		this.showPage(0);
+		this.showPage(0, false);
 		this.show();
 	}
 
-	public done(): void {
+	public async done(validate: boolean = true): Promise<void> {
 		if (this._wizard.doneButton.enabled) {
+			if (validate && !await this._wizard.validateNavigation(undefined)) {
+				return;
+			}
 			this._onDone.fire();
 			this.dispose();
 			this.hide();

src/sql/sqlops.proposed.d.ts

@@ -621,7 +621,7 @@ declare module 'sqlops' {
 				lastPage: number,
 
 				/**
-				 * The new page number
+				 * The new page number or undefined if the user is closing the wizard
 				 */
 				newPage: number
 			}
@@ -734,6 +734,16 @@ declare module 'sqlops' {
 				 * Close the wizard. Does nothing if the wizard is not open.
 				 */
 				close(): Thenable<void>;
+
+				/**
+				 * Register a callback that will be called when the user tries to navigate by
+				 * changing pages or clicking done. Only one callback can be registered at once, so
+				 * each registration call will clear the previous registration.
+				 * @param validator The callback that gets executed when the user tries to
+				 * navigate. Return true to allow the navigation to proceed, or false to
+				 * cancel it.
+				 */
+				registerNavigationValidator(validator: (pageChangeInfo: WizardPageChangeInfo) => boolean | Thenable<boolean>): void;
 			}
 		}
 	}

src/sql/workbench/api/node/extHostModelViewDialog.ts

@@ -217,6 +217,7 @@ class WizardImpl implements sqlops.window.modelviewdialog.Wizard {
 	public customButtons: sqlops.window.modelviewdialog.Button[];
 	private _pageChangedEmitter = new Emitter<sqlops.window.modelviewdialog.WizardPageChangeInfo>();
 	public readonly onPageChanged = this._pageChangedEmitter.event;
+	private _navigationValidator: (info: sqlops.window.modelviewdialog.WizardPageChangeInfo) => boolean | Thenable<boolean>;
 
 	constructor(public title: string, private _extHostModelViewDialog: ExtHostModelViewDialog) {
 		this.doneButton = this._extHostModelViewDialog.createButton(DONE_LABEL);
@@ -225,6 +226,7 @@ class WizardImpl implements sqlops.window.modelviewdialog.Wizard {
 		this.nextButton = this._extHostModelViewDialog.createButton(NEXT_LABEL);
 		this.backButton = this._extHostModelViewDialog.createButton(PREVIOUS_LABEL);
 		this._extHostModelViewDialog.registerWizardPageInfoChangedCallback(this, info => this.handlePageInfoChanged(info));
+		this._currentPage = 0;
 		this.onPageChanged(info => this._currentPage = info.newPage);
 	}
 
@@ -254,6 +256,18 @@ class WizardImpl implements sqlops.window.modelviewdialog.Wizard {
 		return this._extHostModelViewDialog.closeWizard(this);
 	}
 
+	public registerNavigationValidator(validator: (pageChangeInfo: sqlops.window.modelviewdialog.WizardPageChangeInfo) => boolean | Thenable<boolean>): void {
+		this._navigationValidator = validator;
+	}
+
+	public validateNavigation(info: sqlops.window.modelviewdialog.WizardPageChangeInfo): Thenable<boolean> {
+		if (this._navigationValidator) {
+			return Promise.resolve(this._navigationValidator(info));
+		} else {
+			return Promise.resolve(true);
+		}
+	}
+
 	private handlePageInfoChanged(info: WizardPageEventInfo): void {
 		this._currentPage = info.pageChangeInfo.newPage;
 		if (info.eventType === WizardPageInfoEventType.PageAddedOrRemoved) {
@@ -335,6 +349,11 @@ export class ExtHostModelViewDialog implements ExtHostModelViewDialogShape {
 		}
 	}
 
+	public $validateNavigation(handle: number, info: sqlops.window.modelviewdialog.WizardPageChangeInfo): Thenable<boolean> {
+		let wizard = this._objectsByHandle.get(handle) as WizardImpl;
+		return wizard.validateNavigation(info);
+	}
+
 	public openDialog(dialog: sqlops.window.modelviewdialog.Dialog): void {
 		let handle = this.getHandle(dialog);
 		this.updateDialogContent(dialog);

src/sql/workbench/api/node/mainThreadModelViewDialog.ts

@@ -157,6 +157,7 @@ export class MainThreadModelViewDialog implements MainThreadModelViewDialogShape
 			wizard.onPageChanged(info => this._proxy.$onWizardPageChanged(handle, info));
 			wizard.onPageAdded(() => this.handleWizardPageAddedOrRemoved(handle));
 			wizard.onPageRemoved(() => this.handleWizardPageAddedOrRemoved(handle));
+			wizard.registerNavigationValidator(info => this.validateNavigation(handle, info));
 			this._wizards.set(handle, wizard);
 		}
 
@@ -254,4 +255,8 @@ export class MainThreadModelViewDialog implements MainThreadModelViewDialogShape
 		let wizard = this._wizards.get(handle);
 		this._proxy.$updateWizardPageInfo(handle, wizard.pages.map(page => this._wizardPageHandles.get(page)), wizard.currentPage);
 	}
+
+	private validateNavigation(handle: number, info: sqlops.window.modelviewdialog.WizardPageChangeInfo): Thenable<boolean> {
+		return this._proxy.$validateNavigation(handle, info);
+	}
 }

src/sql/workbench/api/node/sqlExtHost.protocol.ts

@@ -556,6 +556,7 @@ export interface ExtHostModelViewDialogShape {
 	$onPanelValidityChanged(handle: number, valid: boolean): void;
 	$onWizardPageChanged(handle: number, info: sqlops.window.modelviewdialog.WizardPageChangeInfo): void;
 	$updateWizardPageInfo(handle: number, pageHandles: number[], currentPageIndex: number): void;
+	$validateNavigation(handle: number, info: sqlops.window.modelviewdialog.WizardPageChangeInfo): Thenable<boolean>;
 }
 
 export interface MainThreadModelViewDialogShape extends IDisposable {