Printing on Android device with Angular - javascript

I have an application where I need to print content that doesn't exist on the page but does exist in the angular template. In the template, I have a div with a click method that will accept an identifier, and then build an iframe based on the content of the id it received. The first snippet is what the clickable element looks like.
<div (click)="printButton('#printThis')" class="menu-item print-menu-item">Race {{ raceSelected?.raceNumber }}</div>
This code snippet is just a basic element with omitted private data. So it will just be an ng-template with an identifier and an iframe that I access from the method pasted below.
<ng-template #printThat>
// content that I will print but not important for this question
</ng-template>
<ng-template #printThis>
// content that I will print but not important for this question
</ng-template>
<iframe #iframe></iframe>
The last code snippet is the method on the component that builds the iframe and brings up the print dialog.
public async printButton(printMode: string): Promise<void> {
let printTemplate;
if (printMode === '#printThat') {
await this.getAllRacesForPrint()
printTemplate = this.printAll;
} else if (printMode === '#printThis') {
printTemplate = this.printSingleRace;
}
const iframe = this.iframe.nativeElement;
this.portalHost = new DomPortalOutlet(
iframe.contentDocument.body,
this.componentFactoryResolver,
this.appRef,
this.injector
);
const portal = new TemplatePortal(
printTemplate,
this.viewContainerRef
);
// Attach portal to host
this.portalHost.attach(portal);
iframe.contentWindow.onafterprint = () => {
iframe.contentDocument.body.innerHTML = '';
};
this._attachStyles(iframe.contentWindow);
iframe.contentWindow.print();
}
These two private functions are invoked in the method above to add the css to the iframe.
private _attachStyles(targetWindow: Window): void {
// Copy styles from parent window
document.querySelectorAll('style').forEach((htmlElement) => {
targetWindow.document.head.appendChild(htmlElement.cloneNode(true));
});
// Copy stylesheet link from parent window.
const styleSheetElement = this._getStyleSheetElement();
targetWindow.document.head.appendChild(styleSheetElement);
}
private _getStyleSheetElement(): HTMLLinkElement {
const styleSheetElement = document.createElement('link');
document.querySelectorAll('link').forEach((htmlElement) => {
if (htmlElement.rel === 'stylesheet') {
const absoluteUrl = new URL(htmlElement.href).href;
styleSheetElement.rel = 'stylesheet';
styleSheetElement.type = 'text/css';
styleSheetElement.href = absoluteUrl;
}
});
return styleSheetElement;
}
This works perfectly on all devices without a problem EXCEPT Android devices. On Android, the print dialog box comes up but the page is blank and has no content. Are there any good solutions for printing for Android that do not require bringing in a package or am I missing something here?

Related

Cannot appendChild to a custom web component

I have a web-component at root level. The simplified version of which is shown below:
class AppLayout {
constructor() {
super();
this.noShadow = true;
}
connectedCallback() {
super.connectedCallback();
this.render();
this.insertAdjacentHTML("afterbegin", this.navigation);
}
render() {
this.innerHTML = this.template;
}
get template() {
return `
<h1>Hello</h1>
`;
}
navigation = `
<script type="module">
import './components/nav-bar.js'
</script>
`;
}
customElements.define('app-layout', AppLayout);
I want to load a script after this component loads. The script creates html for navigation and tries to add it to the app-layout element shown above. However, even though, it does find the app-layout element, it is unable to append the navBar element. It is, however, able to append the navBar to the body of the html. Any ideas what I'm missing.
const navLinks =
`<ul>
<li>Some</li>
<li>Links</li>
</ul>
`;
const navBar = document.createElement('nav');
navBar.innerHTML = navLinks;
const appLayout = document.querySelector('app-layout'); // works with 'body' but not with 'appLayout'
console.log(appLayout); // Logs correct element
appLayout.appendChild(navBar);
I know that what I'm trying to do here (loading a script inside a web component) is not ideal, however, I would like to still understand why the above doesn't work.
using innerHTML or in your case insertAdjacentHTML to add <script> tags to the document doesn't work because browsers historically try to prevent potential cross site script attacks (https://www.w3.org/TR/2008/WD-html5-20080610/dom.html#innerhtml0)
What you could do is something like:
const s = document.createElement("script");
s.type = "module";
s.innerText = `import './components/nav-bar.js'`;
this.append(s);
// or simply directly without the script: `import('./comp..')` if it is really your only js in the script tag.

how can scripts get the current route location in SPA

I am trying to add tracking script in .js file to my angular 12 application.
(function() {
var ds = document.getElementsByTagName("script")[0];
var dm = document.createElement("img");
dm.width = 1;
dm.height = 1;
dm.alt = " ";
dm.src = "https://example.com/url=" + window.location.href;
ds.parentNode.insertBefore(dm, ds);
})();
Script fires properly on the first page, but doesn't fire on navigating to another page on my website. When i check in elements window.location.href is not changing for the new page. It is because of SPA. How can i get latest location on all pages and script to fire on all pages
You could do it the Angular way, although idk if that will work.
You can go into your root component (should be AppComponent), and simply throw this inside the constructor or ngOnInit()
#Component({
...
})
export class AppComponent {
constructor(router: Router) {
router.events.pipe(
filter(route => route instanceof NavigationEnd),
concatMap((route) => ajax('https://example.com/url=' + route.url)),
).subscribe();
}
}
Unless you need your tracker to be an Img for some reason, or you get permission / CORS issues. This should work nicely

Loading HTML file content in a Vue component

I'm having troubles loading the content of an HTML file in a Vue component. Basically i have a Django backend that generates an HTML file using Bokeh and a library called backtesting.py. My frontend is using Nuxt/Vue, so i can't just load the HTML on the page dynamically.
Here is what the HTML file looks like (it was too long to post here): https://controlc.com/aad9cb7f
The content of that file should be loaded in a basic component:
<template>
<div>
<h1>Some content here</h1>
</div>
</template>
<script>
export default {
components: {
},
data() {
return {
}
},
mounted() {
},
methods: {
}
}
</script>
The problem is that i really don't know how to do that. If i just copy and paste the content in the vue component, i'll get a lot of error due to the fact that i'm using a <script> tag in a component. The only thing i managed to do was to load the BokehJS CDN in my index.html file, but even after that i'll get a Bokeh is undefined error in the component.
What can i do to accomplish this? Any kind of advice is appreciated
Tao's answer is spot on and is very similar to how I've solved this issue for myself in the past.
However, I'd like to throw in an alternative iframe approach that could work in case reactivity is important. Here's a codesandbox link
The only difference is that this approach loads the code/HTML via XHR and writes it manually into the iframe. Using this approach, you should be able to add some reactivity if necessary.
<script>
export default {
components: {},
data() {
return {};
},
async mounted() {
this.initialize();
},
methods: {
async initialize() {
const html = await this.loadHTML();
const doc = this.htmlToDocument(html);
this.updateIframe(doc);
},
async loadHTML() {
const response = await fetch("/plot");
const text = await response.text();
return text;
},
htmlToDocument(html) {
const parser = new DOMParser();
const doc = parser.parseFromString(html, "text/html");
return doc;
},
updateIframe(doc) {
const iframe = this.$refs.frame;
const iframeDocument = iframe.contentWindow.document;
iframeDocument.open();
iframeDocument.write(doc.documentElement.innerHTML);
iframeDocument.close();
}
},
};
</script>
In the codesandbox, I've thrown in two additional methods to give you an example of how reactivity can work with this approach:
modify() {
if (this.orig) {
// Only for the purpose of this example.
// It's already been modified. Just short-circuit so we don't overwrite it
return;
}
const bokehDoc = this.$refs.frame.contentWindow.Bokeh.documents[0];
// Get access to the data..not sure if there's a better/proper way
const models = [...bokehDoc._all_models.values()];
const modelWithData = models.find((x) => x.data);
const { data } = modelWithData;
const idx = Math.floor(data.Close.length / 2);
// Store old data so we can reset it
this.orig = data.Close[idx];
data.Close[Math.floor(data.Close.length / 2)] = 0;
modelWithData.change.emit();
},
reset() {
if (!this.orig) {
return;
}
const bokehDoc = this.$refs.frame.contentWindow.Bokeh.documents[0];
// Get access to the data..not sure if there's a better/proper way
const models = [...bokehDoc._all_models.values()];
const modelWithData = models.find((x) => x.data);
const { data } = modelWithData;
const idx = Math.floor(data.Close.length / 2);
data.Close[idx] = this.orig;
modelWithData.change.emit();
delete this.orig;
}
Probably the simplest way is to make your HTML available at the URL of your choice, on your server (regardless of Vue).
Then, in your app, use an <iframe> and point its src to that html. Here's an example, using codesandbox.io, where I placed what you posted into the index.html. Below you can see it working with both <iframe> and <object> tags:
Vue.config.productionTip = false;
Vue.config.devtools = false;
new Vue({
'el': '#app'
})
body {
margin: 0;
}
h1, h3 {padding-left: 1rem;}
object, iframe {
border: none;
height: 800px;
width: 100%;
min-height: calc(100vh - 125px);
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<h1>This content is placed in Vue</h1>
<h3>Vue doesn't really care.</h3>
<iframe src="https://1gk6z.csb.app/"></iframe>
<h1><code><object></code> works, too:</h1>
<object type="text/html" data="https://1gk6z.csb.app/"></object>
</div>
Note: if the domain serving the graph and the one displaying it differ, you'll need server-side configuration to allow the embed (most domains have it turned off by default).
Strategy:
insert and init bokeh in head tag of public/index.html
read file in a string via ajax/xhr and parse as dom tree
extract each needed dom element from the parsed tree
recreate and append each element
No iframe needed. window.Bokeh is directly accessible.
A skeletal example of reactivity is suggested through the method logBkh that logs the global Bokeh object when clicking on the graph
<template>
<div id="app">
<div id="page-container" #click="logBkh"></div>
</div>
</template>
<script>
// loaded from filesystem for test purposes
import page from 'raw-loader!./assets/page.txt'
// parse as dom tree
const extDoc = new DOMParser().parseFromString(page, 'text/html');
export default {
methods: {
logBkh(){
console.log(window.Bokeh)
}
},
mounted() {
const pageContainer = document.querySelector('#page-container')
// generate and append root div
const dv = document.createElement('div')
const { attributes } = extDoc.querySelector('.bk-root')
for(const attr in attributes) {
dv.setAttribute(attributes[attr].name, attributes[attr].value)
}
pageContainer.append(dv)
for(const _scrpt of extDoc.body.querySelectorAll('script')) {
// generate and append each script
const scrpt = document.createElement('script')
for(const attr in _scrpt.attributes) {
scrpt.setAttribute(
_scrpt.attributes[attr].name,
_scrpt.attributes[attr].value
)
}
scrpt.innerHTML = _scrpt.innerHTML
pageContainer.append(scrpt)
}
}
}
</script>
result:

React Portals - Execute function that references new window's DOM

I'm trying to create a React Portal that when mounted, requires running a specific line to load an ActiveReports Designer component.
Here's is my portal code:
constructor(props: IWindowPortalProps) {
super(props);
this.containerEl = document.createElement('div'); // STEP 1: create an empty div
this.containerEl.id = 'designer-host';
this.containerEl.className = styles.designerHost;
this.externalWindow = null;
}
private copyStyles = (sourceDoc: Document, targetDoc: Document) => {
Array.from(sourceDoc.styleSheets).forEach(styleSheet => {
if (styleSheet.cssRules) { // true for inline styles
const newStyleEl = sourceDoc.createElement('style');
Array.from(styleSheet.cssRules).forEach(cssRule => {
newStyleEl.appendChild(sourceDoc.createTextNode(cssRule.cssText));
});
targetDoc.head.appendChild(newStyleEl);
} else if (styleSheet.href) { // true for stylesheets loaded from a URL
const newLinkEl = sourceDoc.createElement('link');
newLinkEl.rel = 'stylesheet';
newLinkEl.href = styleSheet.href;
targetDoc.head.appendChild(newLinkEl);
}
});
}
componentDidMount() {
this.externalWindow = window.open('', '', `height=${window.screen.height},width=${window.screen.width}`);
this.externalWindow.document.body.appendChild(this.containerEl);
this.externalWindow.document.title = 'A React portal window';
this.externalWindow.addEventListener('load', () => {
new Designer('#designer-host');
});
}
render() {
return ReactDOM.createPortal(null, this.containerEl);
}
However, when the new window loads, I get the error
Error: Cannot find the host element. at Function.<anonymous>
which indicates that the designer-host div is not there. I think the load function points to the main DOM and not the new window's one.
Alternatively, I tried appending the ActiveReports .js file by doing in my componentDidMount()
s.type = "text/javascript";
s.src = "../node_modules/#grapecity/activereports/lib/node_modules/#grapecity/ar-js-designer/index.js";
this.externalWindow.document.head.append(s);
and then assigning the Designer instantiation on the onLoad property of the element. Again with no luck.
Is there maybe a way I could run JavaScript a code after the portal has been loaded and point to that DOM?
Thank you
I work for GrapeCity. Could you please go to our support portal and submit a ticket. We will need a full code sample for us to be able to answer this question. Please give us a download link to the sample within the ticket.
Thank you

How to inject webkitRequestFullscreen() into UWP WebView

I have a WebView control in a UWP app which loads a Steam broadcast page URL. It works well and I also have a full-screen button to switch the whole window to full screen.
But the Steam broadcast has its own full-screen toggle button, which I would like to click programmatically so that when I press my full screen button, both the window and the broadcast are switched to full screen.
I tried to achieve this via JS injection, but it seems that the webkitRequestFullscreen() function only responds if it's called inside an event handler. How can I inject an event handler into the WebView and call it?
Here's the XAML:
<Grid Background="{StaticResource AppBackgroundColor}">
<Grid.RowDefinitions>
<RowDefinition Height="*"></RowDefinition>
<RowDefinition Height="Auto"></RowDefinition>
</Grid.RowDefinitions>
<WebView Grid.Row="0" x:Name="Browser" />
<CommandBar x:Name="WatchCommandBar" Grid.Row="1" FlowDirection="LeftToRight">
<AppBarButton Icon="FullScreen" Label="Full Screen" Tapped="AppBarFullScreenButton_Tapped" />
</CommandBar>
</Grid>
And here's the C#:
private void AppBarFullScreenButton_Tapped(object sender, RoutedEventArgs e)
{
var view = ApplicationView.GetForCurrentView();
if (view.IsFullScreenMode)
{
view.ExitFullScreenMode();
WatchCommandBar.Visibility = Visibility.Visible;
}
else
{
view.TryEnterFullScreenMode();
WatchCommandBar.Visibility = Visibility.Collapsed;
}
}
I've tried calling these functions when switching to full-screen, but neither of them work:
await Browser.InvokeScriptAsync("eval", new [] { "BroadcastWatch.m_playerUI.ToggleFullscreen();" });
await Browser.InvokeScriptAsync("eval", new [] { "document.getElementById('videoplayer').webkitRequestFullscreen();" });
Apparently it's not possible to inject the full screen request. And I wasn't able to spoof the mouse click event that would theoretically make the request either.
As a workaround I ended up hiding and styling elements that I did not want to see by injecting this script when the WebView has finished loading:
private async void Browser_HideElements(object sender, WebViewDOMContentLoadedEventArgs args)
{
try
{
var elementsToHide = "#global_header, #footer_spacer, #footer_responsive_optin_spacer, #footer, #ChatWindow, .BroadcastInfoWrapper, .fullscreen_button";
// Hide HTML elements and change styles so it looks like the broadcast is in full-screen
// We can't call the broadcast's own toggle full-screen function
var lines = new[]
{
"document.body.style.overflow = 'hidden';",
"document.getElementById('video_wrapper').className += ' fullscreen';",
"document.getElementById('video_content').style.padding = 0;",
"document.getElementById('video_content').style.margin = 0;",
"document.getElementsByClassName('pagecontent')[0].style.padding = 0;",
"var list = document.querySelectorAll('" + elementsToHide + "');",
"for (var i = 0; i < list.length; i++) { var e = list[i]; e.style.display = 'none'; }"
};
await Browser.InvokeScriptAsync("eval", new[] { string.Join(" ", lines) });
}
catch
{
// Ignore script exceptions
}
}
So it looks like the broadcast is running in full screen, and when my own button is pressed, the title bar disappears and it goes into proper full screen.

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