How to import and use different packages of the same name

Question

For example, I want to use both text/template and html/template in one source file. But the code below throw errors.

import (
    "fmt"
    "net/http"
    "text/template" // template redeclared as imported package name
    "html/template" // template redeclared as imported package name
)

func handler_html(w http.ResponseWriter, r *http.Request) {
    t_html, err := html.template.New("foo").Parse(`{{define "T"}}Hello, {{.}}!{{end}}`)
    t_text, err := text.template.New("foo").Parse(`{{define "T"}}Hello, {{.}}!{{end}}`)

}

score 331 · Accepted Answer · answered May 02 '12 at 06:24

331

import (
    "text/template"
    htemplate "html/template" // this is now imported as htemplate
)

Read more about it in the spec.

answered May 02 '12 at 06:24

Mostafa

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9

JS nailed it with the clarity of `require` and `import` statements, just so much better than any other languages I've seen – Andy Sep 21 '17 at 16:49
1

@r3wt: Best. Language. Ever! – Matt Joiner Mar 17 '18 at 02:56
7

There is no best language, only languages better for some problems etc. – Inanc Gumus Mar 09 '20 at 11:19
Any convention on how we should name the imported package? Short and small case is general recommendation. But what in case we can't come up with any meaningful short name? Which one is preferable - `multi_word` or `multiWord`? – mrpandey Apr 17 '23 at 19:55

Inanc Gumus · Answer 2 · 2020-05-15T08:37:52.850

Answer by Mostafa is correct, however it demands some explanation. Let me try to answer it.

Your example code doesn't work because you're trying to import two packages with the same name, which is: " template ".

import "html/template"  // imports the package as `template`
import "text/template"  // imports the package as `template` (again)

Importing is a declaration statement:

You can't declare the same name (terminology: identifier) in the same scope.
In Go, import is a declaration and its scope is the file that's trying to import those packages.
It doesn't work because of the same reason that you can't declare variables with the same name in the same block.

The following code works:

package main

import (
    t "text/template"
    h "html/template"
)

func main() {
    t.New("foo").Parse(`{{define "T"}}Hello, {{.}}!{{end}}`)
    h.New("foo").Parse(`{{define "T"}}Hello, {{.}}!{{end}}`)
}

The code above gives two different names to the imported packages with the same name. So, there are now two different identifiers that you can use: t for the text/template package, and h for the html/template package.

You can check it on the playground.

How to import and use different packages of the same name

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