Initial support for allowing plugins to modify the Webview Configuration

[macdja38]

Solves #1097

Allows a plugin to modify the WKWebViewConfiguration as follows:

import Foundation
import Capacitor

@objc(IgnoreViewPortScaleLimitsPlugin)
public class IgnoreViewPortScaleLimitsPlugin: CAPPlugin {
    public static override func configureWKWebView(configuration: WKWebViewConfiguration) {
        configuration.ignoresViewportScaleLimits = true
    }
}

Drawbacks at the moment is nothing stops two conflicting modifications from conflicting, no simple way of warning the user that a plugin is overwriting another plugin, not sure if plugins are loaded consistently so it's hard to say if things will fail in consistent ways.

Not sure where to document this, seems it should be documented in the same place as load but I can't find where load is documented… Maybe It should be here? https://capacitor.ionicframework.com/docs/plugins/ios But that's a guide not really documentation…

If someone from the capacitor team could let me know where to document it along with if they're interested in merging this / know of a better way to go about this please let me know then I'll finish it up and remove the draft status.

[eliellis]

I’m currently experiencing an issue that could be totally fixed by this! If anyone from the team could respond to this that’d be awesome.

[skyleguy]

would love if the ignoresViewportScaleLimits field was configurable from my codebase!

[imhoffd]

Thanks for the PR! This doesn't feel like the right way to solve this use case. We'd be open to looking at a PR that adds a configuration value for Capacitor that would alter ignoresViewportScaleLimits in WKWebView, but maybe it's best to wait. We're about to start major refactors for Capacitor 3.

I created #3179 to track this.