Make sort tpl func accept field/key chaining arg

'sort' template function used to accept only each element's struct field
name, method name and map key name as its second argument. This extends
it to accept a field/method/key chaining key string like
'Params.foo.bar' as the argument. It evaluates sub elements of each
array or map elements and sorts by them.

Typical use case would be sorting pages by user defined front matter
value. For example, sorting pages by 'Params.foo.bar' is possible by
writing the following template code

    {{ range sort .Data.Pages "Params.foo.bar" }}
        {{ .Content }}
    {{ end }}

It ignores all leading and trailing dots so "Params.foo.bar" can be
written in ".Params.foo.bar"

This also fixes the issue that 'sort' cannot evaluate a pointer value.

Fix #1330
This commit is contained in:
Tatsushi Demachi 2015-08-07 20:05:18 +09:00 committed by Bjørn Erik Pedersen
parent 56534beaf6
commit 153332706a
2 changed files with 181 additions and 40 deletions

View file

@ -882,32 +882,51 @@ func Sort(seq interface{}, args ...interface{}) (interface{}, error) {
return nil, errors.New("can't iterate over a nil value")
}
switch seqv.Kind() {
case reflect.Array, reflect.Slice, reflect.Map:
// ok
default:
return nil, errors.New("can't sort " + reflect.ValueOf(seq).Type().String())
}
// Create a list of pairs that will be used to do the sort
p := pairList{SortAsc: true, SliceType: reflect.SliceOf(seqv.Type().Elem())}
p.Pairs = make([]pair, seqv.Len())
var sortByField string
for i, l := range args {
dStr, err := cast.ToStringE(l)
switch {
case i == 0 && err != nil:
p.SortByField = ""
sortByField = ""
case i == 0 && err == nil:
p.SortByField = dStr
sortByField = dStr
case i == 1 && err == nil && dStr == "desc":
p.SortAsc = false
case i == 1:
p.SortAsc = true
}
}
path := strings.Split(strings.Trim(sortByField, "."), ".")
switch seqv.Kind() {
case reflect.Array, reflect.Slice:
for i := 0; i < seqv.Len(); i++ {
p.Pairs[i].Key = reflect.ValueOf(i)
p.Pairs[i].Value = seqv.Index(i)
}
if p.SortByField == "" {
p.SortByField = "value"
if sortByField == "" || sortByField == "value" {
p.Pairs[i].SortByValue = p.Pairs[i].Value
} else {
v := p.Pairs[i].Value
var err error
for _, elemName := range path {
v, err = evaluateSubElem(v, elemName)
if err != nil {
return nil, err
}
}
p.Pairs[i].SortByValue = v
}
}
case reflect.Map:
@ -915,10 +934,22 @@ func Sort(seq interface{}, args ...interface{}) (interface{}, error) {
for i := 0; i < seqv.Len(); i++ {
p.Pairs[i].Key = keys[i]
p.Pairs[i].Value = seqv.MapIndex(keys[i])
if sortByField == "" {
p.Pairs[i].SortByValue = p.Pairs[i].Key
} else if sortByField == "value" {
p.Pairs[i].SortByValue = p.Pairs[i].Value
} else {
v := p.Pairs[i].Value
var err error
for _, elemName := range path {
v, err = evaluateSubElem(v, elemName)
if err != nil {
return nil, err
}
}
p.Pairs[i].SortByValue = v
}
}
default:
return nil, errors.New("can't sort " + reflect.ValueOf(seq).Type().String())
}
return p.sort(), nil
}
@ -927,40 +958,22 @@ func Sort(seq interface{}, args ...interface{}) (interface{}, error) {
// https://groups.google.com/forum/#!topic/golang-nuts/FT7cjmcL7gw
// A data structure to hold a key/value pair.
type pair struct {
Key reflect.Value
Value reflect.Value
Key reflect.Value
Value reflect.Value
SortByValue reflect.Value
}
// A slice of pairs that implements sort.Interface to sort by Value.
type pairList struct {
Pairs []pair
SortByField string
SortAsc bool
SliceType reflect.Type
Pairs []pair
SortAsc bool
SliceType reflect.Type
}
func (p pairList) Swap(i, j int) { p.Pairs[i], p.Pairs[j] = p.Pairs[j], p.Pairs[i] }
func (p pairList) Len() int { return len(p.Pairs) }
func (p pairList) Less(i, j int) bool {
var truth bool
switch {
case p.SortByField == "value":
iVal := p.Pairs[i].Value
jVal := p.Pairs[j].Value
truth = Lt(iVal.Interface(), jVal.Interface())
case p.SortByField != "":
if p.Pairs[i].Value.FieldByName(p.SortByField).IsValid() {
iVal := p.Pairs[i].Value.FieldByName(p.SortByField)
jVal := p.Pairs[j].Value.FieldByName(p.SortByField)
truth = Lt(iVal.Interface(), jVal.Interface())
}
default:
iVal := p.Pairs[i].Key
jVal := p.Pairs[j].Key
truth = Lt(iVal.Interface(), jVal.Interface())
}
return truth
return Lt(p.Pairs[i].SortByValue.Interface(), p.Pairs[j].SortByValue.Interface())
}
// sorts a pairList and returns a slice of sorted values

View file

@ -1081,6 +1081,10 @@ func TestSort(t *testing.T) {
MyFloat float64
MyString string
}
type mid struct {
Tst TstX
}
for i, this := range []struct {
sequence interface{}
sortByField interface{}
@ -1091,6 +1095,8 @@ func TestSort(t *testing.T) {
{[]string{"class3", "class1", "class2"}, nil, "asc", []string{"class1", "class2", "class3"}},
{[]int{1, 2, 3, 4, 5}, nil, "asc", []int{1, 2, 3, 4, 5}},
{[]int{5, 4, 3, 1, 2}, nil, "asc", []int{1, 2, 3, 4, 5}},
// test sort key parameter is focibly set empty
{[]string{"class3", "class1", "class2"}, map[int]string{1: "a"}, "asc", []string{"class1", "class2", "class3"}},
// test map sorting by keys
{map[string]int{"1": 10, "2": 20, "3": 30, "4": 40, "5": 50}, nil, "asc", []int{10, 20, 30, 40, 50}},
{map[string]int{"3": 10, "2": 20, "1": 30, "4": 40, "5": 50}, nil, "asc", []int{30, 20, 10, 40, 50}},
@ -1122,9 +1128,124 @@ func TestSort(t *testing.T) {
"asc",
[]ts{{50, 50.5, "fifty"}, {40, 40.5, "forty"}, {10, 10.5, "ten"}, {30, 30.5, "thirty"}, {20, 20.5, "twenty"}},
},
// Test sort desc
// test sort desc
{[]string{"class1", "class2", "class3"}, "value", "desc", []string{"class3", "class2", "class1"}},
{[]string{"class3", "class1", "class2"}, "value", "desc", []string{"class3", "class2", "class1"}},
// test sort by struct's method
{
[]TstX{{A: "i", B: "j"}, {A: "e", B: "f"}, {A: "c", B: "d"}, {A: "g", B: "h"}, {A: "a", B: "b"}},
"TstRv",
"asc",
[]TstX{{A: "a", B: "b"}, {A: "c", B: "d"}, {A: "e", B: "f"}, {A: "g", B: "h"}, {A: "i", B: "j"}},
},
{
[]*TstX{{A: "i", B: "j"}, {A: "e", B: "f"}, {A: "c", B: "d"}, {A: "g", B: "h"}, {A: "a", B: "b"}},
"TstRp",
"asc",
[]*TstX{{A: "a", B: "b"}, {A: "c", B: "d"}, {A: "e", B: "f"}, {A: "g", B: "h"}, {A: "i", B: "j"}},
},
// test map sorting by struct's method
{
map[string]TstX{"1": {A: "i", B: "j"}, "2": {A: "e", B: "f"}, "3": {A: "c", B: "d"}, "4": {A: "g", B: "h"}, "5": {A: "a", B: "b"}},
"TstRv",
"asc",
[]TstX{{A: "a", B: "b"}, {A: "c", B: "d"}, {A: "e", B: "f"}, {A: "g", B: "h"}, {A: "i", B: "j"}},
},
{
map[string]*TstX{"1": {A: "i", B: "j"}, "2": {A: "e", B: "f"}, "3": {A: "c", B: "d"}, "4": {A: "g", B: "h"}, "5": {A: "a", B: "b"}},
"TstRp",
"asc",
[]*TstX{{A: "a", B: "b"}, {A: "c", B: "d"}, {A: "e", B: "f"}, {A: "g", B: "h"}, {A: "i", B: "j"}},
},
// test sort by dot chaining key argument
{
[]map[string]TstX{{"foo": TstX{A: "e", B: "f"}}, {"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}},
"foo.A",
"asc",
[]map[string]TstX{{"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}, {"foo": TstX{A: "e", B: "f"}}},
},
{
[]map[string]TstX{{"foo": TstX{A: "e", B: "f"}}, {"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}},
".foo.A",
"asc",
[]map[string]TstX{{"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}, {"foo": TstX{A: "e", B: "f"}}},
},
{
[]map[string]TstX{{"foo": TstX{A: "e", B: "f"}}, {"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}},
"foo.TstRv",
"asc",
[]map[string]TstX{{"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}, {"foo": TstX{A: "e", B: "f"}}},
},
{
[]map[string]*TstX{{"foo": &TstX{A: "e", B: "f"}}, {"foo": &TstX{A: "a", B: "b"}}, {"foo": &TstX{A: "c", B: "d"}}},
"foo.TstRp",
"asc",
[]map[string]*TstX{{"foo": &TstX{A: "a", B: "b"}}, {"foo": &TstX{A: "c", B: "d"}}, {"foo": &TstX{A: "e", B: "f"}}},
},
{
[]map[string]mid{{"foo": mid{Tst: TstX{A: "e", B: "f"}}}, {"foo": mid{Tst: TstX{A: "a", B: "b"}}}, {"foo": mid{Tst: TstX{A: "c", B: "d"}}}},
"foo.Tst.A",
"asc",
[]map[string]mid{{"foo": mid{Tst: TstX{A: "a", B: "b"}}}, {"foo": mid{Tst: TstX{A: "c", B: "d"}}}, {"foo": mid{Tst: TstX{A: "e", B: "f"}}}},
},
{
[]map[string]mid{{"foo": mid{Tst: TstX{A: "e", B: "f"}}}, {"foo": mid{Tst: TstX{A: "a", B: "b"}}}, {"foo": mid{Tst: TstX{A: "c", B: "d"}}}},
"foo.Tst.TstRv",
"asc",
[]map[string]mid{{"foo": mid{Tst: TstX{A: "a", B: "b"}}}, {"foo": mid{Tst: TstX{A: "c", B: "d"}}}, {"foo": mid{Tst: TstX{A: "e", B: "f"}}}},
},
// test map sorting by dot chaining key argument
{
map[string]map[string]TstX{"1": {"foo": TstX{A: "e", B: "f"}}, "2": {"foo": TstX{A: "a", B: "b"}}, "3": {"foo": TstX{A: "c", B: "d"}}},
"foo.A",
"asc",
[]map[string]TstX{{"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}, {"foo": TstX{A: "e", B: "f"}}},
},
{
map[string]map[string]TstX{"1": {"foo": TstX{A: "e", B: "f"}}, "2": {"foo": TstX{A: "a", B: "b"}}, "3": {"foo": TstX{A: "c", B: "d"}}},
".foo.A",
"asc",
[]map[string]TstX{{"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}, {"foo": TstX{A: "e", B: "f"}}},
},
{
map[string]map[string]TstX{"1": {"foo": TstX{A: "e", B: "f"}}, "2": {"foo": TstX{A: "a", B: "b"}}, "3": {"foo": TstX{A: "c", B: "d"}}},
"foo.TstRv",
"asc",
[]map[string]TstX{{"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}, {"foo": TstX{A: "e", B: "f"}}},
},
{
map[string]map[string]*TstX{"1": {"foo": &TstX{A: "e", B: "f"}}, "2": {"foo": &TstX{A: "a", B: "b"}}, "3": {"foo": &TstX{A: "c", B: "d"}}},
"foo.TstRp",
"asc",
[]map[string]*TstX{{"foo": &TstX{A: "a", B: "b"}}, {"foo": &TstX{A: "c", B: "d"}}, {"foo": &TstX{A: "e", B: "f"}}},
},
{
map[string]map[string]mid{"1": {"foo": mid{Tst: TstX{A: "e", B: "f"}}}, "2": {"foo": mid{Tst: TstX{A: "a", B: "b"}}}, "3": {"foo": mid{Tst: TstX{A: "c", B: "d"}}}},
"foo.Tst.A",
"asc",
[]map[string]mid{{"foo": mid{Tst: TstX{A: "a", B: "b"}}}, {"foo": mid{Tst: TstX{A: "c", B: "d"}}}, {"foo": mid{Tst: TstX{A: "e", B: "f"}}}},
},
{
map[string]map[string]mid{"1": {"foo": mid{Tst: TstX{A: "e", B: "f"}}}, "2": {"foo": mid{Tst: TstX{A: "a", B: "b"}}}, "3": {"foo": mid{Tst: TstX{A: "c", B: "d"}}}},
"foo.Tst.TstRv",
"asc",
[]map[string]mid{{"foo": mid{Tst: TstX{A: "a", B: "b"}}}, {"foo": mid{Tst: TstX{A: "c", B: "d"}}}, {"foo": mid{Tst: TstX{A: "e", B: "f"}}}},
},
// test error cases
{(*[]TstX)(nil), nil, "asc", false},
{TstX{A: "a", B: "b"}, nil, "asc", false},
{
[]map[string]TstX{{"foo": TstX{A: "e", B: "f"}}, {"foo": TstX{A: "a", B: "b"}}, {"foo": TstX{A: "c", B: "d"}}},
"foo.NotAvailable",
"asc",
false,
},
{
map[string]map[string]TstX{"1": {"foo": TstX{A: "e", B: "f"}}, "2": {"foo": TstX{A: "a", B: "b"}}, "3": {"foo": TstX{A: "c", B: "d"}}},
"foo.NotAvailable",
"asc",
false,
},
} {
var result interface{}
var err error
@ -1133,12 +1254,19 @@ func TestSort(t *testing.T) {
} else {
result, err = Sort(this.sequence, this.sortByField, this.sortAsc)
}
if err != nil {
t.Errorf("[%d] failed: %s", i, err)
continue
}
if !reflect.DeepEqual(result, this.expect) {
t.Errorf("[%d] Sort called on sequence: %v | sortByField: `%v` | got %v but expected %v", i, this.sequence, this.sortByField, result, this.expect)
if b, ok := this.expect.(bool); ok && !b {
if err == nil {
t.Errorf("[%d] Sort didn't return an expected error", i)
}
} else {
if err != nil {
t.Errorf("[%d] failed: %s", i, err)
continue
}
if !reflect.DeepEqual(result, this.expect) {
t.Errorf("[%d] Sort called on sequence: %v | sortByField: `%v` | got %v but expected %v", i, this.sequence, this.sortByField, result, this.expect)
}
}
}
}