javascript - 如何使用 ngDisable 在 Angular 表达式中使用条件？

Question

我有一个 DOM 按钮，当没有用户选择时它被禁用(它在加载时设置为 false)但是，我还需要在数组为空时禁用此按钮。例如，我有一组组，当所有组都已添加后，我想禁用添加按钮。

        <div>
            <label for="entityAvailable">Available Groups</label>
            <select id="entityAvailable" multiple   
                ng-model="selectedAvailableGroups" 
                ng-options="g.name for g in availableGroups | orderBy:'name'">
            </select>
        </div>
        <div id="moveButtons" >
            <button type="button" ng-disabled="!selectedUser || availableGroups == []" ng-click="addUserToGroup()">Add User</button>
            <button type="button" ng-disabled="!selectedUser" ng-click="removeUserFromGroup()">Remove</button>
        </div>
        <div>
            <label for="entityAssigned">Assigned Groups</label>
            <select id="entityAssigned" multiple
                ng-model="selectedAssignedGroups" 
                ng-options="g.name for g in assignedGroups | orderBy:'name'">                       
            </select>
        </div>

Answer 1

你可以做到

ng-disabled="!selectedUser || availableGroups.length == 0"