Add 'where' template function

This commit is contained in:
Tatsushi Demachi 2014-08-16 13:12:34 +09:00 committed by spf13
parent 6e15f652bd
commit 002a5b6756
2 changed files with 93 additions and 0 deletions

View file

@ -109,6 +109,71 @@ func First(limit int, seq interface{}) (interface{}, error) {
return seqv.Slice(0, limit).Interface(), nil return seqv.Slice(0, limit).Interface(), nil
} }
func Where(seq, key, match interface{}) (interface{}, error) {
seqv := reflect.ValueOf(seq)
kv := reflect.ValueOf(key)
mv := reflect.ValueOf(match)
// this is better than my first pass; ripped from text/template/exec.go indirect():
for ; seqv.Kind() == reflect.Ptr || seqv.Kind() == reflect.Interface; seqv = seqv.Elem() {
if seqv.IsNil() {
return nil, errors.New("can't iterate over a nil value")
}
if seqv.Kind() == reflect.Interface && seqv.NumMethod() > 0 {
break
}
}
switch seqv.Kind() {
case reflect.Array, reflect.Slice:
r := reflect.MakeSlice(seqv.Type(), 0, 0)
for i := 0; i < seqv.Len(); i++ {
var vvv reflect.Value
vv := seqv.Index(i)
switch vv.Kind() {
case reflect.Map:
if kv.Type() == vv.Type().Key() && vv.MapIndex(kv).IsValid() {
vvv = vv.MapIndex(kv)
}
case reflect.Struct:
if kv.Kind() == reflect.String && vv.FieldByName(kv.String()).IsValid() {
vvv = vv.FieldByName(kv.String())
}
case reflect.Ptr:
if !vv.IsNil() {
ev := vv.Elem()
switch ev.Kind() {
case reflect.Map:
if kv.Type() == ev.Type().Key() && ev.MapIndex(kv).IsValid() {
vvv = ev.MapIndex(kv)
}
case reflect.Struct:
if kv.Kind() == reflect.String && ev.FieldByName(kv.String()).IsValid() {
vvv = ev.FieldByName(kv.String())
}
}
}
}
if vvv.IsValid() && mv.Type() == vvv.Type() {
switch mv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
if mv.Int() == vvv.Int() {
r = reflect.Append(r, vv)
}
case reflect.String:
if mv.String() == vvv.String() {
r = reflect.Append(r, vv)
}
}
}
}
return r.Interface(), nil
default:
return nil, errors.New("can't iterate over " + reflect.ValueOf(seq).Type().String())
}
}
func IsSet(a interface{}, key interface{}) bool { func IsSet(a interface{}, key interface{}) bool {
av := reflect.ValueOf(a) av := reflect.ValueOf(a)
kv := reflect.ValueOf(key) kv := reflect.ValueOf(key)
@ -211,6 +276,7 @@ func NewTemplate() Template {
"echoParam": ReturnWhenSet, "echoParam": ReturnWhenSet,
"safeHtml": SafeHtml, "safeHtml": SafeHtml,
"first": First, "first": First,
"where": Where,
"highlight": Highlight, "highlight": Highlight,
"add": func(a, b int) int { return a + b }, "add": func(a, b int) int { return a + b },
"sub": func(a, b int) int { return a - b }, "sub": func(a, b int) int { return a - b },

View file

@ -55,3 +55,30 @@ func TestFirst(t *testing.T) {
} }
} }
} }
func TestWhere(t *testing.T) {
type X struct {
A, B string
}
for i, this := range []struct {
sequence interface{}
key interface{}
match interface{}
expect interface{}
}{
{[]map[int]string{{1: "a", 2: "m"}, {1: "c", 2: "d"}, {1: "e", 3: "m"}}, 2, "m", []map[int]string{{1: "a", 2: "m"}}},
{[]map[string]int{{"a": 1, "b": 2}, {"a": 3, "b": 4}, {"a": 5, "x": 4}}, "b", 4, []map[string]int{{"a": 3, "b": 4}}},
{[]X{{"a", "b"}, {"c", "d"}, {"e", "f"}}, "B", "f", []X{{"e", "f"}}},
{[]*map[int]string{&map[int]string{1: "a", 2: "m"}, &map[int]string{1: "c", 2: "d"}, &map[int]string{1: "e", 3: "m"}}, 2, "m", []*map[int]string{&map[int]string{1: "a", 2: "m"}}},
{[]*X{&X{"a", "b"}, &X{"c", "d"}, &X{"e", "f"}}, "B", "f", []*X{&X{"e", "f"}}},
} {
results, err := Where(this.sequence, this.key, this.match)
if err != nil {
t.Errorf("[%d] failed: %s", i, err)
continue
}
if !reflect.DeepEqual(results, this.expect) {
t.Errorf("[%d] Where clause matching %v with %v, got %v but expected %v", i, this.key, this.match, results, this.expect)
}
}
}