can't access to data in template

myal...@gmail.com

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Mar 6, 2015, 3:18:34 AM3/6/15

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hi all gophers

please help me

i write above code :

app.go :

package main

import (
	"fmt"
	"net/http"
	"html/template"
)

var tmpl = template.Must(template.ParseGlob("static/*.html"))

func CheckErr(err error) {
	if err != nil {
		fmt.Println(err)
	}
}

type Data struct {
	Member
	Tools
}

type Member struct {
	Name,Family,Username string
}

type Tools struct {
	Title string
}

func Root(w http.ResponseWriter,r *http.Request) {
	d := Data{}
	var result []Data
	d.Member.Name = "alex"	
	d.Member.Family = "alexfamily"
	d.Member.Username = "myalexer"
	d.Tools.Title = "This is the title"
	result = append(result,d)
	err := tmpl.ExecuteTemplate(w,"root",result)
	CheckErr(err)
}

func main() {
	http.HandleFunc("/",Root)
	http.ListenAndServe(":4040",nil)
}

root.html :

{{define "root"}}
<!DOCTYPE html>
<html>
	<head>
		<title>{{.Tools.Title}}</title>
	</head>
	<body>
		<table>
			<tr>
				<th>name</th>
				<th>family</th>
				<th>username</th>
			</tr>
			{{range .}}
			<tr>
				<td>{{.Member.Name}}</td>
				<td>{{.Member.Family}}</td>
				<td>{{.Member.Username}}</td>
			</tr>
			{{end}}
		</table>
	</body>
</html>
{{end}}

i have a problem with fetch Title from Tools structure

when i run program and call http://localhost:4040/ it return error :

template : root.html:5:17: executing "root" at <.Tools.Title>: can't evaluate field Tools in type []main.Data

how do i do ?

Val

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Mar 6, 2015, 7:15:55 PM3/6/15

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Indeed, Data and []Data are two different types. The slice type doesn't have a field "Tools".

First try removing the <title> tag to fix the crash. Then, think how to design some PageFacade struct which would contain a HTML title, other page fields, and a slice of Data.

myal...@gmail.com

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Mar 7, 2015, 12:50:35 AM3/7/15

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i don't know how do i do !

please give me a example

Message has been deleted

Erfan Akbarimanesh

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Mar 7, 2015, 3:39:48 AM3/7/15

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Hi

Change your structure to :

type Data struct {

Member

Title string

}

type Member struct {

Name,Family,Username string

}

After change struct we must change app.go at this line:

d.Tools.Title = "This is the title"

Change it to :

d.Title = "This is the title"

Finally you can use range for fetch title or any way:

<head>

<title>{{range .}}{{.Title}}{{end}}</title>

</head>

Other gophers in this group can provide other way to us

I hope my answer will help you

Good Luck

Egon

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Mar 7, 2015, 6:26:57 AM3/7/15

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First step, relax.

Second step, take a step back.

Your current, main problem isn't templating, but rather how you have approached the problem. Start with something simpler like: http://play.golang.org/p/OIY9p3N21A

Then incrementally start adding new fields and nesting, that way you can make sure that after adding something it still works. It also helps you understand better how the template package works.

For templates, the printf "%#v" is very helpful for understanding what the current context is and what fields are available.