| commit | 4e5ac45ec5c15dba0f57f80e923a0de6f9f4f511 | [log] [tgz] |
|---|---|---|
| author | Rob Pike <r@golang.org> | Fri Apr 03 13:10:47 2015 -0700 |
| committer | Rob Pike <r@golang.org> | Fri Apr 03 23:40:59 2015 +0000 |
| tree | 93c3b557f655573d1692d9542e17ab384e95805b | |
| parent | 4f2a73011f2d076d97a2b46492ab21f26a33222b [diff] |
text/template: provide a mechanism for options Add one option, which is the motivating example, a way to control what happens when a map is indexed with a key that is not in the map. Rather than do something specific for that case, we provide a simple general option mechanism to avoid adding API if something else comes up. This general approach also makes it easy for html/template to track (and adapt, should that become important). New method: Option(option string...). The option strings are key=value pairs or just simple strings (no =). New option: missingkey: Control the behavior during execution if a map is indexed with a key that is not present in the map. "missingkey=default" or "missingkey=invalid" The default behavior: Do nothing and continue execution. If printed, the result of the index operation is the string "<no value>". "missingkey=zero" The operation returns the zero value for the map type's element. "missingkey=error" Execution stops immediately with an error. Fixes #6288. Change-Id: Id811e2b99dc05aff324d517faac113ef3c25293a Reviewed-on: https://go-review.googlesource.com/8462 Reviewed-by: Robert Griesemer <gri@golang.org>
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