dongshai8330 2018-03-25 06:41
浏览 674


My City struct is like this:

type City struct {
    ID      int
    Name    string
    Regions []Region

And Region struct is:

type Region struct {
    ID               int
    Name             string
    Shops            []Destination
    Masters          []Master
    EducationCenters []Destination

In main I try to do this:


Is it possible to do something like this inside template?

{{range .}}
            {{range .Regions}}
                      {{template "data" .Shops $city $region}}
  • 写回答

2条回答 默认 最新

  • dongxi0523 2018-03-25 10:59

    Quoting from the doc of text/template, the syntax of the {{template}} action:

    {{template "name"}}
        The template with the specified name is executed with nil data.
    {{template "name" pipeline}}
        The template with the specified name is executed with dot set
        to the value of the pipeline.

    This means you may pass one optional data to the template execution, not more. If you want to pass multiple values, you have to wrap them into some single value you pass. For details, see How to pass multiple data to Go template?

    So we should wrap those data into a struct or a map. But we can't write Go code in a template. What we may do is register a function to which we pass these data, and the function may do the "packing" and return a single value which now we can pass to the {{template}} action.

    Here's an example wrapper which simply packs these into a map:

    func Wrap(shops []Destination, cityName, regionName string) map[string]interface{} {
        return map[string]interface{}{
            "Shops":      shops,
            "CityName":   cityName,
            "RegionName": regionName,

    Custom functions can be registered using the Template.Funcs() method, and don't forget you have to do this before you parse the template text.

    Here's a modified template which calls this Wrap() function to produce a single value:

    const src = `
    {{define "data"}}
        City: {{.CityName}}, Region: {{.RegionName}}, Shops: {{.Shops}}
    {{- range . -}}
            {{- range .Regions -}}
                  {{- template "data" (Wrap .Shops $city $region) -}}
    {{- end}}`

    And here's a runnable example showing these in action:

    t := template.Must(template.New("cities.gohtml").Funcs(template.FuncMap{
        "Wrap": Wrap,
    CityWithSomeData := []City{
            Name: "CityA",
            Regions: []Region{
                {Name: "CA-RA", Shops: []Destination{{"CA-RA-SA"}, {"CA-RA-SB"}}},
                {Name: "CA-RB", Shops: []Destination{{"CA-RB-SA"}, {"CA-RB-SB"}}},
            Name: "CityB",
            Regions: []Region{
                {Name: "CB-RA", Shops: []Destination{{"CB-RA-SA"}, {"CB-RA-SB"}}},
                {Name: "CB-RB", Shops: []Destination{{"CB-RB-SA"}, {"CB-RB-SB"}}},
    if err := t.ExecuteTemplate(os.Stdout, "cities.gohtml", CityWithSomeData); err != nil {

    Output (try it on the Go Playground):

    City: CityA, Region: CA-RA, Shops: [{CA-RA-SA} {CA-RA-SB}]
    City: CityA, Region: CA-RB, Shops: [{CA-RB-SA} {CA-RB-SB}]
    City: CityB, Region: CB-RA, Shops: [{CB-RA-SA} {CB-RA-SB}]
    City: CityB, Region: CB-RB, Shops: [{CB-RB-SA} {CB-RB-SB}]
    本回答被题主选为最佳回答 , 对您是否有帮助呢?



  • ¥15 h3.6m 人类行为预测论文复现
  • ¥50 wordpress项目注册报失败刷新后其实是成功状态,请求排查原因
  • ¥20 linxu服务器僵尸进程不释放,代码如何修改?
  • ¥15 pycharm激活不成功
  • ¥40 如果update 一个列名为参数的value
  • ¥15 基于51单片机的水位检测系统设计中LCD1602一直不显示
  • ¥15 OCS2安装出现问题,请大家给点意见
  • ¥15 ros小车启动launch文件报错
  • ¥15 vs2015到期想登陆但是登陆不上
  • ¥15 IPQ5018制作烧录固件,boot运行失败(操作系统-linux)(相关搜索:操作系统)(相关搜索:操作系统)