Add to array from json and execute data in template - templates

Question

I have a little qiestion!
How add to array data from json and execute template. Simple. But Not working!
package main
import (
"fmt"
"html/template"
"os"
"encoding/json"
)
type Person struct {
Name string
Jobs []*Job
}
type Job struct {
Employer string
Role string
}
const templ = `The name is {{.Name}}.
{{with .Jobs}}
{{range .}}
An employer is {{.Employer}}
and the role is {{.Role}}
{{end}}
{{end}}
`
func main() {
job1 := Job{Employer: "Monash", Role: "Honorary"}
job2 := Job{Employer: "Box Hill", Role: "Head of HE"}
byt := []byte(`{"num":6.13,"Jobs":[{"Employer": "test1", "Role": "test1"},{"Employer": "test2", "Role": "test2"}]}`)
var dat map[string]interface{}
if err := json.Unmarshal(byt, &dat); err != nil {
panic(err)
}
fmt.Println(dat)
// HOW ADD FROM ARRAY 'dat' TO STRUCT 'Job'
// LINE 54
person := Person{
Name: "jan",
Jobs: []*Job{&job1, &job2},
}
t := template.New("Person template")
t, err := t.Parse(templ)
checkError(err)
err = t.Execute(os.Stdout, person)
checkError(err)
}
func checkError(err error) {
if err != nil {
fmt.Println("Fatal error ", err.Error())
os.Exit(1)
}
}
Here you can play/test code: http://play.golang.org/p/AB8hGLrLRy
Watch line 46.
Thank you very much!

Answer 1

First thing, your dat var isn't of the right type. You should have something like that:
dat := struct {
Jobs []*Job
}
That way, when unmarshalling your JSON string into dat, the Jobs key will be filled with a array of *Job initialized with your data's array.
I'm using an anonymous struct, but you could also have a named struct (see #RoninDev's comment for an example).
Then, just add them to the person array, something like that:
person.Jobs = append(person.Jobs, jobs.Jobs...)
Note the ... operator, which use an array as a variadic argument.
You can see the full working code on this playground.

Answer 2

You're unmarshalling the json fine, it's just into the most ambiguous type the language offers... You could unbox it with a series of type asserts but I don't recommend it. The json can easily be modeled in Go with a structure like the following;
type Wrapper struct {
Num float64 `json:"num"`
Jobs []*Job `json:"Jobs"`
}
Here's an updated example of your code using that struct; http://play.golang.org/p/aNLK_Uk2km
After you've deserialized them you can just use append to add them to the jobs array in the person object like person.Jobs = append(person.Jobs, dat.Jobs...)