text/template: make redefinition of a template in a set more consistent.

Also make it agree with the documentation. You get an error, unless you're
calling Add explicitly, in which case it panics since that's almost certainly
a bug. The discrepancy was caused by a panic that wasn't turned into
an error along one path; deleted the offending function for clarity.

R=r, rsc
CC=golang-dev
https://golang.org/cl/5354045
This commit is contained in:
Rob Pike 2011-11-08 14:33:07 -08:00
parent 0e5cd9d3f6
commit 3e94e757ef
2 changed files with 9 additions and 15 deletions

View file

@ -71,7 +71,7 @@ func (t *Template) Parse(s string) (tmpl *Template, err error) {
// ParseInSet parses the template definition string to construct an internal
// representation of the template for execution. It also adds the template
// to the set.
// to the set. It is an error if s is already defined in the set.
// Function bindings are checked against those in the set.
func (t *Template) ParseInSet(s string, set *Set) (tmpl *Template, err error) {
var setFuncs FuncMap
@ -82,15 +82,8 @@ func (t *Template) ParseInSet(s string, set *Set) (tmpl *Template, err error) {
if err != nil {
return nil, err
}
t.addToSet(set)
return t, nil
}
// addToSet adds the template to the set, verifying it's not being double-assigned.
func (t *Template) addToSet(set *Set) {
if set == nil || t.set == set {
return
if set != nil {
err = set.add(t)
}
// If double-assigned, Add will panic and we will turn that into an error.
set.Add(t)
return t, err
}

View file

@ -101,8 +101,7 @@ func (s *Set) Execute(wr io.Writer, name string, data interface{}) error {
// Parse parses a string into a set of named templates. Parse may be called
// multiple times for a given set, adding the templates defined in the string
// to the set. If a template is redefined, the element in the set is
// overwritten with the new definition.
// to the set. It is an error if a template has a name already defined in the set.
func (s *Set) Parse(text string) (*Set, error) {
trees, err := parse.Set(text, s.leftDelim, s.rightDelim, s.parseFuncs, builtins)
if err != nil {
@ -112,8 +111,10 @@ func (s *Set) Parse(text string) (*Set, error) {
for name, tree := range trees {
tmpl := New(name)
tmpl.Tree = tree
tmpl.addToSet(s)
s.tmpl[name] = tmpl
err = s.add(tmpl)
if err != nil {
return s, err
}
}
return s, nil
}