Add a system property -Dvaadin.hotswap.fullPageReload=true

[sveinnetnordic]

Describe your motivation

When using HotSwapAgent 2.0.1 the new page merge/update has led to multiple problems/bugs. It is fine for some tasks when changing margins, padding, color, etc - and for Vaadin Copilot.

HotSwapAgent 1.4.2 will do a full refresh. It is always working, and every part of the page is run. It is safe and acts like a real situation when a user loads the page. The page reload also "flash" the page, make me sure it is fresh loaded. I use to add helpers, so I don't need to click on every reload. They will not always work in the new mode. E.g. element.executeJs("setTimeout(()=>{$0.click()},100)", btn.element)

hotswap.fullPageReload default to false

Today I have a duplicate of my SDK, one with HotSwapAgent 2.0.1, the other with HotSwapAgent 1.4.2. Not sure if 1.4.2 will work on newer JDK.

Describe the solution you'd like

With a system property -Dvaadin.hotswap.fullPageReload=true it's easy to switch mode

Also doing the switch in Vaadin Copilot in runtime would be nice, but not necessary

[Artur-]

A workaround for this should be to add a custom VaadinHotswapper implementation that just returns true for all changes (a class + a file META-INF/services/com.vaadin.flow.hotswap.VaadinHotswapper containing the name of the class)

[sveinnetnordic]

class CustomVaadinHotswapper : VaadinHotswapper {
    companion object {
        var fullPageReload = true
    }

    override fun onClassLoadEvent(vaadinService: VaadinService, classes: Set<Class<*>>, redefined: Boolean): Boolean {
        return if (fullPageReload) true else super.onClassLoadEvent(vaadinService, classes, redefined)
    }
}

if (!VaadinService.getCurrent().deploymentConfiguration.isProductionMode) {
            extraInfoBottomLeft.add(Checkbox(CustomVaadinHotswapper.fullPageReload) { CustomVaadinHotswapper.fullPageReload = it.value }.style("--vaadin-checkbox-size: 0.7rem"))
}

This seems to work! Can turn on/off full page reload at runtime

Hope this will be added by Vaadin, with the toggle on the Vaadin Copilot button i browser

[mcollovati]

A minor drawback of this approach is that the page will be reloaded even if the class change does not affect the UI directly.

[sveinnetnordic]

Found that returning true made pages reload twice (not on reload). Returning redefined seems to work

public class CustomVaadinHotswapper implements VaadinHotswapper {
    public static boolean fullPageReload = true;

    @Override
    public boolean onClassLoadEvent(VaadinService vaadinService, Set<Class<?>> classes, boolean redefined) {
        return fullPageReload ? redefined : VaadinHotswapper.super.onClassLoadEvent(vaadinService, classes, redefined);
    }
}