Material-components-web-components: deregisterBodyClickListener not working - possible fix

[cintaccs]

activating - deactivating the menu's keeps registrering the click event listener on MDCMenuSurface.

Possible fix:
menu-surface component
component.js

MDCMenuSurface.prototype.initialSyncWithDOM
        this.deregisterBodyClickListener = function () {
//BEFORE: document.body.removeEventListener('click', _this.handleBodyClick);
//AFTER: add the , { capture: true } to the removeEventListener 
//to match the document.body.addEventListener('click', _this.handleBodyClick, { capture: true });
            document.body.removeEventListener('click', _this.handleBodyClick, { capture: true });
        };

FYI - I will post this suggestion on the material-components/material-components-web too

[dfreedm]

This looks like a bug in the menu surface class itself: https://github.com/material-components/material-components-web-components/blob/master/packages/menu/mwc-menu-surface-base.ts#L341

[cintaccs]

thanks for looking into this - my current "hack" is to do this (in lit-element updated):

this.temp_menu = new MDCMenu(div);
let origHandler = this.temp_menu.menuSurface_.handleBodyClick;
this.temp_menu.menuSurface_.deregisterBodyClickListener = () => {    
    document.body.removeEventListener('click', origHandler, { capture: true });
};

it's ugly - but seems to work.

[cintaccs]

@dfreedm - just out of curiosity - may I ask why these types of memory leak issues are considered "Severity: Low"? As I see it there are a couple of them in the "framework" and when using any of the components (menu and tab bar seems rather widespread) in a SPA the events are adding up and up and up.... when building a solid SPA where users might work for hours - it seems to slow down and refiring etc....?

[zandaqo]

I see it's been fixed in MDC, when is the next release with this fix expected? It's not just a memory leak, by the way, it messes up the logic when you subscribe to the 'closed' event of the menu surface--each undelegated handler emits an event resulting in an avalanche of events increasing the more times you open the menu.

[asyncLiz]

@zandaqo You can use the @canary version of MWC to get the latest version, which will have the MDC fix included, until the next release.

[zandaqo]

The version 0.20.0 fixes this for me, but only when MDCMenuSurface#quick is set to true for some reason.