html/template: execute adds blanks #5534
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Labels changed: added priority-soon, removed priority-triage. Owner changed to @robpike. Status changed to Accepted. |
can't reproduce either. also can't reproduce the standalone test case: http://play.golang.org/p/W9Wpz0NLO1 |
Error is difficult to reproduce, and maybe it depends on the template. Source code in attachments. Attachments:
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smaller standalone test: http://play.golang.org/p/bE7bMu73dG as the added blanks are in the scripts, is it a big deal? |
http://play.golang.org/p/x5VkIAyi3t is even shorter. It needs the javascript escaping, which means it's caused by javascript escaping. I'm not sure it's actually wrong and will find out. Status changed to Accepted. |
http://play.golang.org/p/-qdFFKF-kI minimal version. Оther scripts, too. In general, the scripting language is not known, so in my opinion it is necessary to give content <script></script> as is. |
That's intentional because
x-{{-1}}
should not lead to the token sequence
"x" "--"(decrement) "1"
instead of the probably intended
"x" "-"(binary -) "-"(unary -) "1"
Also the guarantee the IS escaping functions provide is
http://golang.org/src/pkg/html/template/js.go#L133
133 // jsValEscaper escapes its inputs to a JS Expression (section 11.14) that has
134 // neither side-effects nor free variables outside (NaN, Infinity).
and allowing token merging would mean that the simplest sub-expression into which an
interpolation happens could have free variables not in (NaN, Infinity).
It's done at http://golang.org/src/pkg/html/template/js.go#L183
183 // Prevent IdentifierNames and NumericLiterals from running into
184 // keywords: in, instanceof, typeof, void
185 pad := isJSIdentPart(first) || isJSIdentPart(last)
186 if pad {
187 buf.WriteByte(' ')
188 }
If there's a strong use case for merged tokens then content.JS should allow a safety
hatch. If the concern is over output-size, then it should be possible to determine
whether the
Most of the token merging cases shouldn't affect JS that is likely to appear in a
template -- there are few places in a JS program where two identifiers/numbers can be
adjacent; but there's some interest in TC39 for moving towards a less punctuation heavy
syntax.
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by Knyaginin:
package main import ( "strconv" "html/template" "net/http" ) type Page struct { Port int } func hRoot(w http.ResponseWriter, r *http.Request) { t, _ := template.ParseFiles("Root.html") port, _ := strconv.Atoi(r.FormValue("port")) p := &Page{Port: port} t.Execute(w, p) } func main() { http.HandleFunc("/", hRoot) http.ListenAndServe(":9980", nil) } /*Root.html*/ <div>{{.Port}}</div> What is the expected output? <div>1234</div> What do you see instead? <div> 1234 </div> Which operating system are you using? centos 6.4 Which version are you using? (run 'go version') go version devel +772d46cd8fd1 Sat Apr 20 17:20:58 2013 -0700 linux/amd64The text was updated successfully, but these errors were encountered: