英文:
golang template.Execute and struct embedding
问题
我有一个用Go编写的小网站项目，你可以在其中存储链接，但我遇到了一个问题：
该网站有许多不同的页面，显示不同的信息，因此您需要传递不同类型的结构体来执行模板。但是每个页面还需要像用户名和标签这样的信息，这些信息显示在侧边栏中。我尝试了一种方法，而不是为每个页面都创建全新的结构体类型。
http://play.golang.org/p/VNfD6i8p_N
type Page interface {
Name() string
}
type GeneralPage struct {
PageName string
}
func (s GeneralPage) Name() string {
return s.PageName
}
type PageRoot struct {
Page
Tags []string
IsLoggedIn bool
Username string
}
type ListPage struct {
Page
Links []Link
IsTagPage bool
Tag string
}
type GalleryPage struct {
Page
Image Link
Next int
Previous int
}
但是当我执行模板时，出现错误："fp.tmpl" at <.Links>: can't evaluate field Links in type main.Page
错误发生的模板部分：
{{with .Page}}
{{range .Links}}
<tr>
<td>{{if .IsImage}}<img src="{{.Url}}" />{{end}}</td>
<td>{{.Name}}</td>
<td>{{.Url}}</td>
<td>{{.TagsString}}</td>
</tr>
{{end}}
{{end}}
而 {{.Name}} 不起作用。（它是从GeneralPage嵌入的函数）
英文:
I have a little website project written go where you can store links, and I ran into a problem :
The website has many different pages which show different information so you need to pass template.Execute a different kind of a struct. But every page also needs info like username and tags, which are displayed in sidebar. I tried to make something like this instead of just making completely new struct type for each page.
http://play.golang.org/p/VNfD6i8p_N
type Page interface {
Name() string
}
type GeneralPage struct {
PageName string
}
func (s GeneralPage) Name() string {
return s.PageName
}
type PageRoot struct {
Page
Tags []string
IsLoggedIn bool
Username string
}
type ListPage struct {
Page
Links []Link
IsTagPage bool
Tag string
}
type GalleryPage struct {
Page
Image Link
Next int
Previous int
}
But I get an error when I execute the template: "fp.tmpl" at <.Links>: can't evaluate field Links in type main.Page
The part of the template where the error occurs:
{{with .Page}}
{{range .Links}}
<tr>
<td>{{if .IsImage}}<img src="{{.Url}}" />{{end}}</td>
<td>{{.Name}}</td>
<td>{{.Url}}</td>
<td>{{.TagsString}}</td>
</tr>
{{end}}
{{end}}
And {{.Name}} doesn't work. (It's the function embedded from GeneralPage)
答案1
得分: 1
你正在嵌入Page接口，但你需要的是GeneralPage。也许你可以使用map[string]interface{}来存储你的数据（然后在模板中检查是否为非nil），这样更容易。但你可以共享主要布局，只需更改细节（就像主页面）。请参考http://golang.org/pkg/text/template/#example_Template_share。
英文:
You're embeding the Page interface, but what you need is GeneralPage.
Maybe you can use a map[string]interface{} to store your data (and then check if not-nil in your template), it easier.
But you can share the main layout and just change the detail (like a master page).
Look at http://golang.org/pkg/text/template/#example_Template_share
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论