从 Grails 中的布局视图访问模型 [英] Accessing the model from a layout view in Grails

问题描述

我在 Grails 中使用了布局支持 (sitemesh)，效果很好.我想根据用户是否登录来调整我的布局.

I'm using the layout support (sitemesh) in Grails which works fine. I'd like to adjust my layout to have it depend on whether or not a user is logged in or not.

我的 grails-app/views/layouts/main.gsp 包含以下代码:

My grails-app/views/layouts/main.gsp contains the following code:

<g:if test="${user}">
  Username: ${user.username}
</g:if>

但是，似乎 layout-GSP:s 无法访问模型，因此无法访问用户变量(尝试时出现无会话"异常).使我的布局取决于用户是否登录的推荐方法是什么?

However, it appears as if the layout-GSP:s are unable to access the model and hence the user variable (I get a "No session" exception when trying). What would be the recommended way to make my layout depend on whether or not a user is logged in or not?

提前致谢！

推荐答案

我建议为此目的使用请求或会话范围.可能最干燥的方法是填充范围是过滤器.例如在文件 grails-app/conf/SecurityFilters.groovy 中(您需要创建它):

I would suggest to use either the request or the session scope for that purpose. Probably the most DRY way is to populate the scope is a filter. For example in the file grails-app/conf/SecurityFilters.groovy (you'll need to create it):

class SecurityFilters {

    def filters = {
        populateCurrentUser(controller: '*', action: '*') {
            before = {
                 request.user = User.get(session.userId)
            }
        }
    }
}    

该示例假设您将当前用户的 id 存储在会话属性userId"中，并且您有一个域类User".在布局中使用它就像这样简单:

The example assumes that you store the id of the current user in the session attribute "userId" and that you have a Domain class "User". Using it in the layout is as simple as this:

<g:if test="${request.user}">
   Current User: ${request.user.username}
</g:if>

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