Why is URL not whitelisted in allowed globals?

[jfbrennan]

Was surprised that I couldn't do this because URL is not allowed in templates:

<img :src="URL.createObjectURL(blob)">

Why?

[Alfred-Skyblue]

See https://vuejs.org/guide/essentials/template-syntax.html#restricted-globals-access

You can try expanding the globally accessible properties in the template using the following approach:

const app = createApp()

app.config.globalProperties.URL = URL

[jfbrennan]

I know. My question is why. If that works, then why restrict and create confusion/friction for developers?

[Justineo]

As per #7939 (comment):

The template global whitelist has always only included language-level globals (as defined in ECMA-262).

Apart from that, using URL.createObjectURL() in template expressions is not a good idea as there will be no way to release the created object with URL.revokeObjectURL(), which will lead to memory leaks.

[jfbrennan]

I'm really just interested in URL usage in general. The example was hasty, just me hacking around and discovering URL is blocked.

But fwiw, yes you can revoke. Vue actually makes it easy (well, it could if it didn't block URL):

<img :src="objectURL" @load="URL.revokeObjectURL(objectURL)">

If app.config.globalProperties.URL = URL works, then why block people from using it in the first place?