Xamarin WebView erroneous CanGoBack on single-page app - xamarin

I'm new to mobile app dev, so I'm not sure whether this is Xamarin related, or is it just a general limitation on webview controls, or whether this is specific to Android (only tested it on android...), or whether its me just not understanding the underlying tech thoroughly :)
I'm building an app that has a WebView to some site.
The site is built with AngularJS and utilizes the HistoryAPI for manipulating navigation.
I started experimenting with Xamarin for the implementation.
I used the WebView sample and just updated the url to point to my site.
But it seems the sample is not functioning as it should for navigation.
The CanGoBack getter always returns false on my site and it seems to be related to the historyApi navigation...
One more note - if I bypass the CanGoBack and just call GoBack the view actually goes back to previous page, but of course this is unacceptable...

Related

Configure platform page with platform specific options

We've begun evaluating Xamarin for a up and coming project involving both iOS and Android, with the overriding intention to produce a single UI layer (and some share code, obviously) (I'm also new to C#)
TL;DR
I've begun exploring Xamarin on iOS. I started with the Phoneword example and it worked well enough.
The first issue I found was running the code on the iPhone X, which I was able to solve by using MainPage.On<Xamarin.Forms.PlatformConfiguration.iOS>().SetUseSafeArea(true); in the platform App class
While testing this, I noticed some issues with the ListView not scrolling properly (the core issue was actually with the platform padding).
I then used (MainPage as Xamarin.Forms.NavigationPage).On<iOS>().EnableTranslucentNavigationBar(); to enable translucent navigation bars (as we're targeting iOS 11+) and now everything appears under the navigation bar.
This is easily fixed in xCode and after some research I've found that I need to be using UIKit.UIViewController.EdgesForExtendedLayout Property, the immediate problem I'm facing is, the only "snippets" of code I can find are from the View is displayed under status bar in iOS 7 and EdgesForExtendedLayout doesn't help forum post.
Issue at hand...
The example solution snippets posted seem to be making use of a platform (iOS) specific solution. The problem is, I want to keep using the "cross-platform" code in the "platform" project and simply provide some custom configuration for the iOS platform which can apply these states.
I understand it could be possible to use a renderer, but this seems to counter-interactive, as I'd need one for both iOS and Android, where the platform page is doing just fine as it.
I understand that I could setup a DependencyService, but this seems annoying to have to include a specific "configuration" service just to solve this issue for iOS
I was hoping it might be possible to setup a iOS Page which would "override" some of the functionality of the platform page and would allow me to make use of things like viewDidLoad so I can apply the iOS specific configurations on a page by pages bases, so we could keep the platform page as it, but when running under iOS, it would provide me access to iOS life cycle of the actual view...
I've been trying to search the documentation and tutorials and haven't yet come across anything which would seem to do this or something similar (not to say there isn't one, but I'm just not finding it).

Building a webview wrapper app with Xamarin

I wonder which is the best approach for building a webview wrapper application.
The app will load the website and nothing more. which browser engine uses Xamarin? Is it good to run a CMS website that contains chat, profile page, and many other complex features.
Any tips?
ps: I will use my own website not someone elses.

Is there an up to date Xamarin component for BLE? The website links to a 404 page

I'm trying to implempent cross-platform bluetooth functionality into my Xamarin application for IOS and Android, but the links on the Xamarin website are deprecated and/or missing from the site entirely.
https://developer.xamarin.com/samples/mobile/BluetoothLEExplorer/
This link is where the documentation sends me, and the page states that the code is deprecated and links to something else called Monkey Robotics, however that component is no longer available in the component store. Am I missing something here?

How can Xamarin be used to wrap a web app as if it were a native app for Android?

Say I build a super mobile friendly web application that I want in the Play Store for Android users to be able to download.
Could I use Xamarin to:
Wrap the entire mobile app as a single WebView
Register for mobile push notifications
Essentially shortlining an MVP of an android app by using an existing web app? If so, is there any well-known process or documentation that demonstrates this?
Probably the best approach for you would be using Xamarin Forms with one or more pages containing only web views.
I don't love Xamarin Forms because usually for me Xamarin Android+iOS gives a better result in similar time, but your app would be so simple that doesn't make sense to do it with Xamarin Android.
Make sure that your web app will show only what makes sense to be shown in your app, otherwise you risk to see double header/footer, useless buttons... but if the website is yours adding a few parameters to change a bit the UI won't be a problem I guess.
Have a look at this example:
https://github.com/xamarin/xamarin-forms-samples/tree/master/WorkingWithWebview
Another approach is the use of Razor to build your pages in html directly inside your app, but if I understood well it's not what you need:
https://developer.xamarin.com/guides/cross-platform/advanced/razor_html_templates/
Although it is technically possible to do this as the previous answer has suggested. I would recommended firstly reviewing, the relevant stores guidelines on submissions. Apple for example will not allow a submission to their store of any application that simply mirrors the functionality of a website. I suspect Google's would likely be the same.
However that said, to answer your question, Xamarin.Forms would be appropriate for a simple application like the one you are suggesting. Or if you prefer to build to a specific OS, then in iOS with Xamarin you would use the Safari View Controller that was added in it's xcode 8.1 release. Android uses something similar as does windows.
EDIT:
You can use the Web View control in Xamarins Andorid native PCL project to encapsulate your mobile friendly website within an application here is the documentation:
Xamarin Android Developer link to Android Web View
As for push notifications, yes this is perfectly possible using Xamarin.Android. and varies on implementation depending on what you want to use as the back end to handle them, I.E. Azure's notification hub etc.

WebView vs WKWebView on OSX

Apple's documentation suggests using WkWebView for new development, although it seems to have a typo where it recommends WKWebView over UIWebView in the mac developer library.
For new development, employ this class instead of the older UIWebView class.
The typo is probably because they are trying to unify the OSX and iOS interface to the web view by using the same header for both.
However, WKWebView doesn't have all the functionality that WebView has in OSX. For example, you can get access to DOM nodes in the native interface in WebView but I don't see any way of doing this from Swift/Objective-C in WKWebView.
For my purposes, it seems like WebView is what I need, but I'm weary of starting a project that relies on an API that will be removed. However, I don't see any mention of intent to deprecate WebView anywhere in the headers or the documentation.
What makes this even more confusing is the WebKit Framework Reference makes reference to both WK and older web view APIs without clarifying anything.
WKWebView
A WKWebView object displays interactive web content, such as for an in-app browser.
WebView
WebView is the core view class in the WebKit framework that manages interactions between the WebFrame and WebFrameView classes.
Is WebView going away in OSX?
Its not a false alarm. Apple moved Safari off of UIWebView/WebView in 6.0, so security fixes simply aren't happening in the old class as much. For that reason alone you should not use it for new stuff. Apple has been incrementally improving it with every OS release so much is now do-able with private extensions (file:// access, downloads, etc)
That being said, it won't be fully equivalent to old WebView. You can't directly access the DOM anymore because the Network/Rendering/UI processes were split up and you create locks by making element references like that. Use the postMessage() message handler and wkwebview.evaluateJavaScript() and callback-ish/promisy JS code between those two pillars to deal with web<>native interaction asynchronously.
Important
Starting in iOS 8.0 and OS X 10.10, use WKWebView to add web content to your app.
Do not use UIWebView or WebView.
https://developer.apple.com/documentation/webkit/wkwebview

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