Web View

The WebView component is used to display web content within your application. You use the control by providing a src attribute that points at a URL or a local HTML file.

Events

The example shows the how to use the events supported by the WebView component and its reload method.

XML
JavaScript
TypeScript

<GridLayout rows="50 50 50 *" columns="* *">
    <Button row="0" col="0" text="Load first url" tap="loadFirst" />
    <Button row="0" col="1" text="Load second url" tap="loadSecond" />
    <Button row="1" col="0" colSpan="2" text="Reload page" tap="onReload" />
    <Label row="2" col="0" colSpan="2" text="{{ 'Url: ' + webViewSrc }}" textWrap="true" class="p-12" />

    <WebView id="webview" row="3" col="0" colSpan="2" loadStarted="onLoadStarted" loadFinished="onLoadFinished" src="{{ webViewSrc }}" />
    <GridLayout class="indicator" visibility="{{ isItemVisible ? 'visible' : 'collapsed' }}" row="0" col="0" rowSpan="4" colSpan="2">
            <ActivityIndicator width="100" height="100" busy="true"/>
    </GridLayout>
</GridLayout>

function onNavigatingTo(args) {
    const page = args.object;
    const vm = new Observable();
    vm.set("webViewSrc", secondUrl);
    vm.set("isItemVisible", true);
    page.bindingContext = vm;
}

function onLoadStarted(args) {
    const page = args.object;
    const vm = page.bindingContext;
    vm.set("isItemVisible", true);
    let message;
    if (!args.error) {
        message = `WebView started loading of ${args.url}`;
    } else {
        message = `Error loading  ${args.url} : ${args.error}`;
    }
    console.log(message);

}
function onLoadFinished(args) {
    const page = args.object;
    const vm = page.bindingContext;
    let message;
    if (!args.error) {
        message = `WebView finished loading of  ${args.url}`;
    } else {
        message = `Error loading ${args.url} : ${args.error}`;
    }
    console.log(message);
}

function loadFirst(args) {
    const page = args.object.page;
    const vm = page.bindingContext;
    vm.set("webViewSrc", firstUrl);
}

function loadSecond(args) {
    const page = args.object.page;
    const vm = page.bindingContext;
    vm.set("webViewSrc", secondUrl);
}

function onReload(args) {
    const page = args.object.page;
    webview = page.getViewById("webview");
    webview.reload();
}

exports.onNavigatingTo = onNavigatingTo;
exports.onLoadStarted = onLoadStarted;
exports.onLoadFinished = onLoadFinished;
exports.loadFirst = loadFirst;
exports.loadSecond = loadSecond;
exports.onReload = onReload;

export function onNavigatingTo(args) {
    const page: Page = <Page>args.object;
    const vm = new Observable();
    vm.set("webViewSrc", secondUrl);
    vm.set("isItemVisible", true);
    page.bindingContext = vm;
}

export function onLoadStarted(args) {
    const page: Page = <Page>args.object;
    const vm = page.bindingContext;
    vm.set("isItemVisible", true);
    let message;
    if (!args.error) {
        message = `WebView started loading of ${args.url}`;
    } else {
        message = `Error loading  ${args.url} : ${args.error}`;
    }
    console.log(message);

}
export function onLoadFinished(args) {
    const page = (<Page>args.object);
    const vm = page.bindingContext;
    let message;
    if (!args.error) {
        message = `WebView finished loading of  ${args.url}`;
    } else {
        message = `Error loading ${args.url} : ${args.error}`;
    }
    console.log(message);
}

export function loadFirst(args) {
    const page: Page = <Page>args.object.page;
    const vm = page.bindingContext;
    vm.set("webViewSrc", firstUrl);
}

export function loadSecond(args) {
    const page: Page = <Page>args.object.page;
    const vm = page.bindingContext;
    vm.set("webViewSrc", secondUrl);
}

export function onReload(args) {
    const page: Page = <Page>args.object.page;
    const webview: WebView = <WebView>page.getViewById("webview");
    webview.reload();
}

In the sample code, we set up event loadStarted and loadFinished events. Both events will be fired when we change the source for the WebView component(change the URL or load local HTML file). The loadStarted event will be executed when the WebView source start loading and loadFinished will be fired when the source is already loaded. The events will return info about the eventName, navigationType and url, which we are trying to load. If an error appears on some of the steps of source load, we will receive the corresponding error with the error property in loadStarted or loadFinished events.

In the provided sample, it is also demonstrated how to reload the currently loaded source via WebView's reload method.

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Demo Source

Gestures

The code samples show, how we could use gestures in WebView for both platforms iOS and Android.

XML
JavaScript
TypeScript

 <GridLayout rows="50 50 *">
    <Label row="0" text="{{ touchResult }}" textWrap="true" />
    <Label row="1" text="{{ panResult }}" textWrap="true" />
    <WebView row="2" loaded="onWebViewLoaded"  touch="webViewTouch" pan="webViewPan" src="{{ webViewSrc }}" />
</GridLayout>

function onNavigatingTo(args) {
    const page = args.object;
    const vm = new Observable();
    vm.set("webViewSrc", "<!DOCTYPE html><html><body><h1>My First Heading</h1><p>My first paragraph.</p></body></html>");
    vm.set("touchResult", "Touch: x: _ y: _");
    vm.set("panResult", "Pan: deltaX: _ deltaY: _");
    page.bindingContext = vm;
}
// disabling the WebView's zoom control(required only for Android)
function onWebViewLoaded(webargs) {
    const webview = webargs.object;
    if (platformModule.isAndroid) {
        webview.android.getSettings().setDisplayZoomControls(false);
    }
}
// setting up Touch gesture callback method
function webViewTouch(args) {
    const page = args.object.page;
    const vm = page.bindingContext;
    vm.set("touchResult", `Touch: x: ${args.getX().toFixed(3)} y: ${args.getY().toFixed(3)}`);
    console.log(`Touch: x: ${args.getX().toFixed(3)} y: ${args.getY().toFixed(3)}`);
}
// setting up Pan gesture callback method
function webViewPan(args) {
    const page = args.object.page;
    const vm = page.bindingContext;
    vm.set("panResult", `Pan: deltaX: ${args.deltaX.toFixed(3)} deltaY: ${args.deltaY.toFixed(3)}`);
    console.log(`Pan: deltaX: ${args.deltaX.toFixed(3)} deltaY: ${args.deltaY.toFixed(3)}`);
}

exports.onNavigatingTo = onNavigatingTo;
exports.onWebViewLoaded = onWebViewLoaded;
exports.webViewTouch = webViewTouch;
exports.webViewPan = webViewPan;

export function onNavigatingTo(args) {
    const page: Page = <Page>args.object;
    const vm = new Observable();
    vm.set("webViewSrc", "<!DOCTYPE html><html><body><h1>My First Heading</h1><p>My first paragraph.</p></body></html>");
    vm.set("touchResult", "Touch: x: _ y: _");
    vm.set("panResult", "Pan: deltaX: _ deltaY: _");
    page.bindingContext = vm;
}
// disabling the WebView's zoom control(required only for Android)
export function onWebViewLoaded(webargs) {
    const webview: WebView = <WebView>webargs.object;
    if (isAndroid) {
        webview.android.getSettings().setDisplayZoomControls(false);
    }
}
// setting up Touch gesture callback method
export function webViewTouch(args) {
    const page: Page = <Page>args.object.page;
    const vm = page.bindingContext;
    vm.set("touchResult", `Touch: x: ${args.getX().toFixed(3)} y: ${args.getY().toFixed(3)}`);
    console.log(`Touch: x: ${args.getX().toFixed(3)} y: ${args.getY().toFixed(3)}`);
}
// setting up Pan gesture callback method
export function webViewPan(args) {
    const page: Page = <Page>args.object.page;
    const vm = page.bindingContext;
    vm.set("panResult", `Pan: deltaX: ${args.deltaX.toFixed(3)} deltaY: ${args.deltaY.toFixed(3)}`);
    console.log(`Pan: deltaX: ${args.deltaX.toFixed(3)} deltaY: ${args.deltaY.toFixed(3)}`);
}

Note: to be able to use gestures in WebView component on Android, we should first disabled the zoom control. To do that we could access the android property and with the help of setDisplayZoomControls to set this control to false.

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Demo Source

Source Load

The example demonstrates, how to load content in the WebView component, while using a local file or while providing HTML code directly to its src property.

XML

<GridLayout rows="100 50 * 50" columns="*">
    <WebView row="0" col="0" loaded="onFirstWebViewLoaded" src="{{ firstWebViewSRC }}"/>
    <Label row="1" text="{{ resultFirstWebView }}" textWrap="true" />
    <WebView row="2" col="0" loaded="onSecondWebViewLoaded" src="{{ secondWebViewSRC }}"/>
    <Label row="3" text="{{ resultSecondWebView }}" textWrap="true" />
</GridLayout>

Add WebView src from local file

JavaScript
TypeScript

const Observable = require("tns-core-modules/data/observable").Observable;
const webViewModule = require("tns-core-modules/ui/web-view");
function onNavigatingTo(args) {
    const page = args.object;
    const vm = new Observable();
    // loading the WebView source while providing a HTML code
    vm.set("firstWebViewSRC", "<!DOCTYPE html><html><head><title>MyTitle</title><meta charset='utf-8' /></head><body><span style='color:#0099CC; text-align: center;'>First WebView</span></body></html>");
    vm.set("resultFirstWebView", "");
    // loading the WebView source from a local file
    vm.set("secondWebViewSRC", "~/ns-ui-widgets-category/web-view/source-load/test.html");
    vm.set("resultSecondWebView", "");
    page.bindingContext = vm;
}

function onFirstWebViewLoaded(webargs) {
    const page = webargs.object.page;
    const vm = page.bindingContext;
    const webview = webargs.object;
    vm.set("resultFirstWebView", "First WebView is still loading...");
    // handling WebView load finish event
    webview.on(webViewModule.WebView.loadFinishedEvent, (args) => {
        let message = "";
        if (!args.error) {
            message = `First WebView finished loading of ${args.url}`;
        } else {
            message = `Error loading first WebView ${args.url} : ${args.error}`;
        }

        vm.set("resultFirstWebView", message);
        console.log("First WebView message - ", message);
    });
}

function onSecondWebViewLoaded(webargs) {
    const page = webargs.object.page;
    const vm = page.bindingContext;
    const webview = webargs.object;
    vm.set("resultSecondWebView", "Second WebView is still loading...");

    webview.on(webViewModule.WebView.loadFinishedEvent, (args) => {
        let message = "";
        if (!args.error) {
            message = `Second WebView finished loading of ${args.url}`;
        } else {
            message = `Error loading second WebView  ${args.url} : ${args.error}`;
        }

        vm.set("resultSecondWebView", message);
        console.log("Second WebView message - ", message);
    });
}

exports.onNavigatingTo = onNavigatingTo;
exports.onFirstWebViewLoaded = onFirstWebViewLoaded;
exports.onSecondWebViewLoaded = onSecondWebViewLoaded;

import {Observable} from "tns-core-modules/data/observable";
import {WebView, LoadEventData} from "tns-core-modules/ui/web-view";
import {Page} from "tns-core-modules/ui/page";
export function onNavigatingTo(args) {
    const page: Page = <Page> args.object;
    const vm = new Observable();
    // loading the WebView source while providing a HTML code
    vm.set("firstWebViewSRC", "<!DOCTYPE html><html><head><title>MyTitle</title><meta charset='utf-8' /></head><body><span style='color:#0099CC; text-align: center;'>First WebView</span></body></html>");
    vm.set("resultFirstWebView", "");
    // loading the WebView source from a local file
    vm.set("secondWebViewSRC", "~/ns-ui-widgets-category/web-view/source-load/test.html");
    vm.set("resultSecondWebView", "");
    page.bindingContext = vm;
}

export function onFirstWebViewLoaded(webargs) {
    const page: Page = <Page> webargs.object.page;
    const vm = page.bindingContext;
    const webview: WebView = <WebView> webargs.object;
    vm.set("resultFirstWebView", "First WebView is still loading...");
    // handling WebView load finish event
    webview.on(WebView.loadFinishedEvent, (args: LoadEventData) => {
        let message = "";
        if (!args.error) {
            message = `First WebView finished loading of ${args.url}`;
        } else {
            message = `Error loading first WebView ${args.url} : ${args.error}`;
        }

        vm.set("resultFirstWebView", message);
        console.log("First WebView message - ", message);
    });
}

export function onSecondWebViewLoaded(webargs) {
    const page: Page = <Page> webargs.object.page;
    const vm = page.bindingContext;
    const webview: WebView = <WebView>webargs.object;
    vm.set("resultSecondWebView", "Second WebView is still loading...");

    webview.on(WebView.loadFinishedEvent, (args: LoadEventData) => {
        let message = "";
        if (!args.error) {
            message = `Second WebView finished loading of ${args.url}`;
        } else {
            message = `Error loading second WebView  ${args.url} : ${args.error}`;
        }

        vm.set("resultSecondWebView", message);
        console.log("Second WebView message - ", message);
    });
}

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Demo Source

API Reference for the WebView Class

Native Component

Android	iOS
android.webkit.WebView	WKWebView

NativeScript Core

Web View

Basics

Events

Gestures

Source Load