hasViewPermission() {
			if (!this.isObject(env.nodespec) || !env.nodespec.satisfied)
				return null;

			return !env.nodespec.readonly;
		}
Check whether a view has sufficient permissions.

@return {boolean|null}
Returns `null` if the current session has no permission at all to
load resources required by the view. Returns `false` if readonly
permissions are granted or `true` if at least one required ACL
group is granted with write permissions.