goweb/template/html/helper.go

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2018-12-06 15:18:05 +01:00
package html
import (
"encoding/json"
"errors"
"reflect"
"unicode/utf8"
)
func dump(args ...interface{}) (string, error) {
out := ""
for _, a := range args {
str, err := json.MarshalIndent(a, "", " ")
if err != nil {
return "", err
}
out += string(str) + "\n"
}
return out, nil
}
func increment(value int) int {
return value + 1
}
func ellipsis(str string, max int) string {
if utf8.RuneCountInString(str) > max {
return string([]rune(str)[0:(max-3)]) + "..."
}
return str
}
func customMap(values ...interface{}) (map[string]interface{}, error) {
if len(values)%2 != 0 {
return nil, errors.New("invalid custoMmap call")
}
customMap := make(map[string]interface{}, len(values)/2)
for i := 0; i < len(values); i += 2 {
key, ok := values[i].(string)
if !ok {
return nil, errors.New("map keys must be strings")
}
customMap[key] = values[i+1]
}
return customMap, nil
}
func defaultVal(src interface{}, defaultValue interface{}) interface{} {
switch typ := src.(type) {
case string:
if typ == "" {
return defaultValue
}
default:
if src == nil {
return defaultValue
}
}
return src
}
func has(v interface{}, name string) bool {
rv := reflect.ValueOf(v)
if rv.Kind() == reflect.Ptr {
rv = rv.Elem()
}
if rv.Kind() != reflect.Struct {
return false
}
return rv.FieldByName(name).IsValid()
}