How can i use a json object in golang template

Question

My goal is to load an object from the database as a json object into a vue application that is rendered in a golang template. The data should be loaded directly into the web page. Does anyone have an idea how to do this?

template.html

<html>
    <body>
      <div id="app">
        <test-component :test="{{index . obj}}"></test-component>
      </div>
    </body>
</html>

server.go

package main

import (
    "html/template"
    "io"
    "net/http"

    "github.com/labstack/echo/v4"
)

// TemplateRenderer is a custom html/template renderer for Echo framework
type TemplateRenderer struct {
    templates *template.Template
}

// Render renders a template document
func (t *TemplateRenderer) Render(w io.Writer, name string, data interface{}, c echo.Context) error {

    // Add global methods if data is a map
    if viewContext, isMap := data.(map[string]interface{}); isMap {
        viewContext["reverse"] = c.Echo().Reverse
    }

    return t.templates.ExecuteTemplate(w, name, data)
}

func main() {
  e := echo.New()
  renderer := &TemplateRenderer{
      templates: template.Must(template.ParseGlob("*.html")),
  }
  e.Renderer = renderer

  // Named route "foobar"
  e.GET("/something", func(c echo.Context) error {
    jsonStr := `{"a":"apple", "b":"banana"}`
        obj := map[string]string{}

        json.Unmarshal([]byte(jsonStr), &obj)
            return c.Render(http.StatusOK, "template.html", obj)
  }).Name = "foobar"

  e.Logger.Fatal(e.Start(":8000"))
}

I use vueJS but it doesn´t matter, it could be any other JS-framework that get the js object injected. — Sienael, Sep 17 '22 at 06:17

score 1 · Answer 1 · answered Sep 17 '22 at 21:15

I found the solution, the template was wrong.

package main

import (
    "html/template"
    "io"
    "net/http"

    "github.com/labstack/echo/v4"
    "github.com/labstack/echo/v4/middleware"
)

type Template struct {
    templates *template.Template
}

func (t *Template) Render(w io.Writer, name string, data interface{}, c echo.Context) error {
    t.templates.Delims("[[", "]]")
    return t.templates.ExecuteTemplate(w, name, data)
}
func Hello(c echo.Context) error {
    test := `{
        "name" : "Ben",
        "country" : "Germany",
        "city" : "Berlin",
        "body":{"test":"test","test2":"test2"}
    }`
    return c.Render(http.StatusOK, "hello", test)
}

func main() {
    // Echo instance
    e := echo.New()

    t := &Template{
        templates: template.Must(template.ParseGlob("public/views/*.html")),
    }

    e.Renderer = t
    e.GET("/hello", Hello)
    // Middleware
    e.Use(middleware.Logger())
    e.Use(middleware.Recover())

    // Start server
    e.Logger.Fatal(e.Start(":8000"))
}

HTML

{{define "hello"}}
<!doctype html>
<html lang="en">
    
<head>
    <meta charset="utf-8">
    <script>
        console.log("golangVar");
        var golangVar = '{{.}}'
        console.log(golangVar);
    </script>
 </head>
 <body>
    {{.}}
 </body>

</html>
{{end}}

How can i use a json object in golang template

1 Answers1