Casl: Breaking CSS Style of third party components

[rahulpsd18]

Hi,

First of all, thanks for the awesome library.

I am unable to keep the style when of my sidebar when using <Can/>. I am using antd to create a sidebar in my app but when I try to conditionally show a menu item based on user's ability, the styles get broken.

How can I make use of <Can/>without breaking the css child combinator styles (.parent > .child > .child2)?

My Code:

<Sider>
    <div className="logo" />
    <Menu theme="dark" mode="inline" defaultSelectedKeys={['1']}>
        <Can I="view" a="applications"> 
            <Menu.Item key="1"> // broken styles as child combinator is not found
                <Icon type="app" />
                <span>Applications</span>
            </Menu.Item>
        </Can>
        <Menu.Item key="2">
            <Icon type="settings" />
            <span>Settings</span>
        </Menu.Item>
    </Menu>
</Sider>

The <li> element generated in case of <Can/> has class "undefined-item" instead of "ant-menu-item", as in case of normal <Menu.Item>.

Using the following versions:

"@casl/ability": "^3.1.2",
"@casl/react": "^1.0.3",
"react": "^16.8.6",
"antd": "^3.20.6",

[stalniy]

Hi,

How did you create <Can> (createContextualCan or createBoundCan)?

[rahulpsd18]

export const Can = createCanBoundTo(ability);

where createCanBoundTo was imported from @casl/react.

I also tried the createContextualCan following the readme but met the same fate.

[stalniy]

<Can> uses React Fragment if available. Probably what I can do is to check if there is exactly one child node then render it directly and if there are more then render in fragment

[rahulpsd18]

That would indeed solve my issue. Thanks!

[stalniy]

After some inverstigation, there is nothing I can do with <Can> component to make this stuff work properly due to how rc-menu works. rc-menu is a lib which is used by antd for menus.

That <Menu> goes over all children, clones them and pass additional properties. When you add <Can> as a child of <Menu>, <Can> receive all props which were supposed to be passed into <Menu.Item>. That's why you can incorrect class and actually not only :) There are other state management callbacks which are passed to <Menu.Item> from <Menu>.

So, it's not a fault of <React.Fragment>. And that changes won't help. There is potential workaround which I don't like:

<Can ...>{(isAllowed, ability, ...restProps) => <Menu.Item {...restProps}>}</Can>

What can you do to make things work?

Instead of <Can> component you can get Ability instance directly from React's context API (but keep in mind, in this case you can't use ability.update() function. Instead you need to create a new Ability instance each time you want to change permissions). There are 2 options:

• useContext hook
• contextType

I updated @casl/react README with that suggestions.

Your code in this case will look like this:

<Sider>
    <div className="logo" />
    <Menu theme="dark" mode="inline" defaultSelectedKeys={['1']}>
        { ability.can('view', 'applications') &&
            <Menu.Item key="1">
                <Icon type="app" />
                <span>Applications</span>
            </Menu.Item>
        }
        <Menu.Item key="2">
            <Icon type="settings" />
            <span>Settings</span>
        </Menu.Item>
    </Menu>
</Sider>

[stalniy]

Close this as there is nothing I can do more with this. You can check my example here: https://codesandbox.io/s/admiring-field-dxc5t

[rahulpsd18]

@stalniy Thanks for the help. I really appreciate you looking at it.