ref: 5d0748ce51d0a86843bfd6569fd3cd18fa20ed5a
parent: 63e2a46f630ea95b6a82ddd7af240f87026871fb
author: digitalcraftsman <[email protected]>
date: Sun Mar 12 19:04:12 EDT 2017
tpl: Add union template func
--- a/docs/content/templates/functions.md
+++ b/docs/content/templates/functions.md
@@ -214,6 +214,23 @@
</ul>
+### union
+Given two arrays (or slices) A and B, this function will return a new array that contains the elements or objects that belong to either A or to B or to both. The elements supported are strings, integers and floats (only float64).
+
+```
+{{ union (slice 1 2 3) (slice 3 4 5) }}+<!-- returns [1 2 3 4 5] -->
+
+{{ union (slice 1 2 3) nil }}+<!-- returns [1 2 3] -->
+
+{{ union nil (slice 1 2 3) }}+<!-- returns [1 2 3] -->
+
+{{ union nil nil }}+<!-- returns an error because both arrays/slices have to be of the same type -->
+```
+
### isset
Returns true if the parameter is set.
Takes either a slice, array or channel and an index or a map and a key as input.
--- a/tpl/tplimpl/template_funcs.go
+++ b/tpl/tplimpl/template_funcs.go
@@ -399,6 +399,55 @@
}
}
+// union returns the union of the given sets, l1 and l2. l1 and
+// l2 must be of the same type and may be either arrays or slices.
+// If l1 and l2 aren't of the same type then l1 will be returned.
+// If either l1 or l2 is nil then the non-nil list will be returned.
+func union(l1, l2 interface{}) (interface{}, error) {+ if l1 == nil && l2 == nil {+ return nil, errors.New("both arrays/slices have to be of the same type")+ } else if l1 == nil && l2 != nil {+ return l2, nil
+ } else if l1 != nil && l2 == nil {+ return l1, nil
+ }
+
+ l1v := reflect.ValueOf(l1)
+ l2v := reflect.ValueOf(l2)
+
+ switch l1v.Kind() {+ case reflect.Array, reflect.Slice:
+ switch l2v.Kind() {+ case reflect.Array, reflect.Slice:
+ r := reflect.MakeSlice(l1v.Type(), 0, 0)
+
+ if l1v.Type() != l2v.Type() {+ return r.Interface(), nil
+ }
+
+ for i := 0; i < l1v.Len(); i++ {+ elem := l1v.Index(i)
+ if !in(r.Interface(), elem.Interface()) {+ r = reflect.Append(r, elem)
+ }
+ }
+
+ for j := 0; j < l2v.Len(); j++ {+ elem := l2v.Index(j)
+ if !in(r.Interface(), elem.Interface()) {+ r = reflect.Append(r, elem)
+ }
+ }
+
+ return r.Interface(), nil
+ default:
+ return nil, errors.New("can't iterate over " + reflect.ValueOf(l2).Type().String())+ }
+ default:
+ return nil, errors.New("can't iterate over " + reflect.ValueOf(l1).Type().String())+ }
+}
+
type imageHandler struct {imageConfigCache map[string]image.Config
sync.RWMutex
@@ -2193,6 +2242,7 @@
"time": asTime,
"trim": trim,
"truncate": truncate,
+ "union": union,
"upper": upper,
"urlize": t.PathSpec.URLize,
"where": where,
--- a/tpl/tplimpl/template_funcs_test.go
+++ b/tpl/tplimpl/template_funcs_test.go
@@ -184,6 +184,7 @@
truncate: {{ "this is a very long text" | truncate 10 " ..." }} truncate: {{ "With [Markdown](/markdown) inside." | markdownify | truncate 14 }} upper: {{upper "BatMan"}}+union: {{ union (slice 1 2 3) (slice 3 4 5) }} urlize: {{ "Bat Man" | urlize }}`
@@ -260,6 +261,7 @@
truncate: this is a ...
truncate: With <a href="/markdown">Markdown …</a>
upper: BATMAN
+union: [1 2 3 4 5]
urlize: bat-man
`
@@ -988,8 +990,6 @@
{[]string{"a", "b"}, []string{"a", "b", "c"}, []string{"a", "b"}}, {[]string{"a", "b", "c"}, []string{"d", "e"}, []string{}}, {[]string{}, []string{}, []string{}},- {[]string{"a", "b"}, nil, make([]interface{}, 0)},- {nil, []string{"a", "b"}, make([]interface{}, 0)}, {nil, nil, make([]interface{}, 0)}, {[]string{"1", "2"}, []int{1, 2}, []string{}}, {[]int{1, 2}, []string{"1", "2"}, []int{}},@@ -1015,6 +1015,53 @@
}
_, err2 := intersect([]string{"a"}, "not an array or slice")+
+ if err2 == nil {+ t.Error("Expected error for non array as second arg")+ }
+}
+
+func TestUnion(t *testing.T) {+ t.Parallel()
+ for i, this := range []struct {+ sequence1 interface{}+ sequence2 interface{}+ expect interface{}+ isErr bool
+ }{+ {[]string{"a", "b", "c", "c"}, []string{"a", "b", "b"}, []string{"a", "b", "c"}, false},+ {[]string{"a", "b"}, []string{"a", "b", "c"}, []string{"a", "b", "c"}, false},+ {[]string{"a", "b", "c"}, []string{"d", "e"}, []string{"a", "b", "c", "d", "e"}, false},+ {[]string{}, []string{}, []string{}, false},+ {[]string{"a", "b"}, nil, []string{"a", "b"}, false},+ {nil, []string{"a", "b"}, []string{"a", "b"}, false},+ {nil, nil, make([]interface{}, 0), true},+ {[]string{"1", "2"}, []int{1, 2}, make([]string, 0), false},+ {[]int{1, 2}, []string{"1", "2"}, make([]int, 0), false},+ {[]int{1, 2, 3}, []int{3, 4, 5}, []int{1, 2, 3, 4, 5}, false},+ {[]int{1, 2, 3}, []int{1, 2, 3}, []int{1, 2, 3}, false},+ {[]int{1, 2, 4}, []int{2, 4}, []int{1, 2, 4}, false},+ {[]int{2, 4}, []int{1, 2, 4}, []int{2, 4, 1}, false},+ {[]int{1, 2, 4}, []int{3, 6}, []int{1, 2, 4, 3, 6}, false},+ {[]float64{2.2, 4.4}, []float64{1.1, 2.2, 4.4}, []float64{2.2, 4.4, 1.1}, false},+ } {+ results, err := union(this.sequence1, this.sequence2)
+ if err != nil && !this.isErr {+ t.Errorf("[%d] failed: %s", i, err)+ continue
+ }
+ if !reflect.DeepEqual(results, this.expect) && !this.isErr {+ t.Errorf("[%d] got %v but expected %v", i, results, this.expect)+ }
+ }
+
+ _, err1 := union("not an array or slice", []string{"a"})+
+ if err1 == nil {+ t.Error("Expected error for non array as first arg")+ }
+
+ _, err2 := union([]string{"a"}, "not an array or slice") if err2 == nil { t.Error("Expected error for non array as second arg")