将*datastore.Key添加到切片中

huangapple
go评论118阅读模式
英文:

Add *datastore.Key to slice

问题

我成功地获取了所有的数据，并使用模板在表格中显示出来。我在这段代码中使用Go语言查询数据存储，实体类型为Membership。

在HTML页面中，所有的数据都被显示出来，但是键值没有显示。

我尝试将Key *datastore.Key作为Membership结构体的属性添加进去，但是仍然没有成功。

以下是我的代码：

  1. package hello
  3. import (
  4.     "appengine"
  5.     "appengine/datastore"
  6.     "html/template"
  7.     "net/http"
  8.     "time"
  9. )        
  11. type Membership struct {
  12.     Key *datastore.Key
  13.     Author  string
  14.     Content string
  15.     FirstName string
  16.     LastName string
  17.     Address string
  18.     Email string 
  19.     Grade string
  20.     Date    time.Time
  21. }
  23. func init() {
  24.     http.HandleFunc("/", members)
  25. }
  27. func members(w http.ResponseWriter, r *http.Request) {
  28.     c := appengine.NewContext(r)
  29.     q := datastore.NewQuery("Membership").Order("-Date")
  30.     memberships := make([]Membership, 0, 10)
  31.     if _, err := q.GetAll(c, &memberships); err != nil {
  32.         http.Error(w, err.Error(), http.StatusInternalServerError)
  33.         return
  34.     }
  35.     if err := membersTemplate.Execute(w, memberships); err != nil {
  36.         http.Error(w, err.Error(), http.StatusInternalServerError)
  37.     }
  38. }
  40. var membersTemplate = template.Must(template.New("page").Parse(membersTemplateHTML))
  42. const membersTemplateHTML = `
  43. <html>
  44.   <body>
  45.     <table><tr><th>Key</th><th>Name</th><th>Email</th><th>Adress</th><th>Grade</th></tr>
  46.       {{range .}}
  47.         <tr>
  48.           <td>{{.Key}}</td>
  49.           <td>{{.FirstName}} {{.LastName}}</td>
  50.           <td>{{.Email}}</td>
  51.           <td>{{.Address}}</td>
  52.           <td>{{.Grade}}</td>
  53.         </tr>
  54.       {{end}}
  55.     </table>
  56.   </body>
  57. </html>`
英文:

I am getting all the data successfully and displayed in a table using template. I am using Go in this code querying the datastore with Membership as entity type.

In the html page, all the data are displayed but not the keys.

I have tried to add Key *datastore.Key as property to the Membership struct but still no luck.

Here is my code:

  1. package hello
  3. import (
  4.     &quot;appengine&quot;
  5.     &quot;appengine/datastore&quot;
  6.     &quot;html/template&quot;
  7.     &quot;net/http&quot;
  8.     &quot;time&quot;
  9. )        
  11. type Membership struct {
  12.     Key *datastore.Key
  13.     Author  string
  14.     Content string
  15.     FirstName string
  16.     LastName string
  17.     Address string
  18.     Email string 
  19.     Grade string
  20.     Date    time.Time
  21. }
  23. func init() {
  24.     http.HandleFunc(&quot;/&quot;, members)
  25. }
  27. func members(w http.ResponseWriter, r *http.Request) {
  28.     c := appengine.NewContext(r)
  29.     q := datastore.NewQuery(&quot;Membership&quot;).Order(&quot;-Date&quot;)
  30.     memberships := make([]Membership, 0, 10)
  31.     if _, err := q.GetAll(c, &amp;memberships); err != nil {
  32.         http.Error(w, err.Error(), http.StatusInternalServerError)
  33.         return
  34.     }
  35.     if err := membersTemplate.Execute(w, memberships); err != nil {
  36.         http.Error(w, err.Error(), http.StatusInternalServerError)
  37.     }
  38. }
  40. var membersTemplate = template.Must(template.New(&quot;page&quot;).Parse(membersTemplateHTML))
  42. const membersTemplateHTML = `
  43. &lt;html&gt;
  44.   &lt;body&gt;
  45.     &lt;table&gt;&lt;tr&gt;&lt;th&gt;Key&lt;/th&gt;&lt;th&gt;Name&lt;/th&gt;&lt;th&gt;Email&lt;/th&gt;&lt;th&gt;Adress&lt;/th&gt;&lt;th&gt;Grade&lt;/th&gt;&lt;/tr&gt;
  46.       {{range .}}
  47.         &lt;tr&gt;
  48.           &lt;td&gt;{{.Key}}&lt;/td&gt;
  49.           &lt;td&gt;{{.FirstName}} {{.LastName}}&lt;/td&gt;
  50.           &lt;td&gt;{{.Email}}&lt;/td&gt;
  51.           &lt;td&gt;{{.Address}}&lt;/td&gt;
  52.           &lt;td&gt;{{.Grade}}&lt;/td&gt;
  53.         &lt;/tr&gt;
  54.       {{end}}
  55.     &lt;/table&gt;
  56.   &lt;/body&gt;
  57. &lt;/html&gt;`

答案1

得分: 3

你需要将键分配给Key属性：

  1. func members(w http.ResponseWriter, r *http.Request) {
  2.   ....
  3.     if keys, err := q.GetAll(c, &memberships); err != nil {
  4.         http.Error(w, err.Error(), http.StatusInternalServerError)
  5.         return
  6.     }
  7.     // 遍历成员并添加键
  8.     for i := range memberships {
  9.          memberships[i].Key = keys[i]
  10.     }
  11.   ....
  12. }

你可能还想禁用在数据存储中存储Key属性：

  1. type Membership struct {
  2.     Key *datastore.Key `datastore:"-"`
  3.     ....
  4. }

顺便说一下，如果你想在HTML中显示*datastore.Key，你应该在显示之前对其进行Encode()处理。

英文:

You need to assign the key to the Key property:

  1. func members(w http.ResponseWriter, r *http.Request) {
  2.   ....
  3.     if keys, err := q.GetAll(c, &amp;memberships); err != nil {
  4.         http.Error(w, err.Error(), http.StatusInternalServerError)
  5.         return
  6.     }
  7.     // Loop over the membership and add the keys
  8.     for i := range memberships {
  9.          memberships[i].Key = keys[i]
  10.     }
  11.   ....
  12. }

You might also want to disable storing the Key property in the datastore:

  1. type Membership struct {
  2.     Key *datastore.Key `datastore:&quot;-&quot;`
  3.     ....
  4. }

Btw. if you want to display the *datastore.Key in HTML, you should Encode() it before.

huangapple
  • 本文由 发表于 2013年1月5日 04:44:06
  • 转载请务必保留本文链接：https://go.coder-hub.com/14164678.html
  • go
  • google-app-engine
  • google-cloud-datastore
  • key
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