code review 5665044: html/template: add Clone and AddParseTree. Make text/te...

html/template: add Clone and AddParseTree. Make text/template's Clone
return (*Template, error), not just *Template.

Fixes issue 2757.

[nigeltao, 2012-02-14 06:14:08]

Hello r@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[r, 2012-02-14 06:26:45]

http://codereview.appspot.com/5665044/diff/2005/src/pkg/html/template/templat...
File src/pkg/html/template/template.go (right):

http://codereview.appspot.com/5665044/diff/2005/src/pkg/html/template/templat...
src/pkg/html/template/template.go:114: if t.escaped {
isn't this racy?

http://codereview.appspot.com/5665044/diff/2005/src/pkg/html/template/templat...
src/pkg/html/template/template.go:115: return nil, fmt.Errorf("html/template:
cannot call AddParseTree after a template has executed")
include the name in the message
AddParseTree(%q)

http://codereview.appspot.com/5665044/diff/2005/src/pkg/html/template/templat...
src/pkg/html/template/template.go:142: if t.escaped {
ditto ditto

[nigeltao, 2012-02-14 07:46:46]

http://codereview.appspot.com/5665044/diff/2005/src/pkg/html/template/templat...
File src/pkg/html/template/template.go (right):

http://codereview.appspot.com/5665044/diff/2005/src/pkg/html/template/templat...
src/pkg/html/template/template.go:114: if t.escaped {
On 2012/02/14 06:26:45, r wrote:
> isn't this racy?

Done.

http://codereview.appspot.com/5665044/diff/2005/src/pkg/html/template/templat...
src/pkg/html/template/template.go:115: return nil, fmt.Errorf("html/template:
cannot call AddParseTree after a template has executed")
On 2012/02/14 06:26:45, r wrote:
> include the name in the message
> AddParseTree(%q)

Done.

http://codereview.appspot.com/5665044/diff/2005/src/pkg/html/template/templat...
src/pkg/html/template/template.go:142: if t.escaped {
On 2012/02/14 06:26:45, r wrote:
> ditto ditto

Done.

[r, 2012-02-14 11:40:19]

http://codereview.appspot.com/5665044/diff/1002/src/pkg/html/template/templat...
File src/pkg/html/template/template.go (right):

http://codereview.appspot.com/5665044/diff/1002/src/pkg/html/template/templat...
src/pkg/html/template/template.go:117: return nil, fmt.Errorf("html/template:
cannot call AddParseTree on template %q after it has executed", t.Name())
html/template: cannot call AddParseTree(%q) after it has executed

http://codereview.appspot.com/5665044/diff/1002/src/pkg/html/template/templat...
src/pkg/html/template/template.go:144: return nil, fmt.Errorf("html/template:
cannot call Clone on template %q after it has executed", t.Name())
html/template: cannot Clone %q after it has executed

http://codereview.appspot.com/5665044/diff/1002/src/pkg/html/template/templat...
src/pkg/html/template/template.go:161: return nil, fmt.Errorf("html/template:
cannot call Clone on template %q after it has executed", t.Name())
ditto
but isn't it one message for two distinguishable errors?

[r, 2012-02-15 05:11:53]

LGTM

[nigeltao, 2012-02-15 05:16:42]

*** Submitted as http://code.google.com/p/go/source/detail?r=67f27df4c2aa ***

html/template: add Clone and AddParseTree. Make text/template's Clone
return (*Template, error), not just *Template.

Fixes issue 2757.

R=r
CC=golang-dev
http://codereview.appspot.com/5665044