hugo/tpl/lang/lang.go
Cameron Moore 93b3b13867 tpl/lang: Add NumFmt function
NumFmt formats a number with a given precision using the requested
decimal, grouping, and negative characters.

Fixes #1444
2017-05-18 09:49:20 +03:00

136 lines
3 KiB
Go

// Copyright 2017 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package lang
import (
"errors"
"math"
"strconv"
"strings"
"github.com/spf13/cast"
"github.com/spf13/hugo/deps"
)
// New returns a new instance of the lang-namespaced template functions.
func New(deps *deps.Deps) *Namespace {
return &Namespace{
deps: deps,
}
}
// Namespace provides template functions for the "lang" namespace.
type Namespace struct {
deps *deps.Deps
}
// Translate ...
func (ns *Namespace) Translate(id interface{}, args ...interface{}) (string, error) {
sid, err := cast.ToStringE(id)
if err != nil {
return "", nil
}
return ns.deps.Translate(sid, args...), nil
}
// NumFmt formats a number with the given precision using the
// negative, decimal, and grouping options. The `options`
// parameter is a string consisting of `<negative> <decimal> <grouping>`. The
// default `options` value is `- . ,`.
//
// Note that numbers are rounded up at 5 or greater.
// So, with precision set to 0, 1.5 becomes `2`, and 1.4 becomes `1`.
func (ns *Namespace) NumFmt(precision, number interface{}, options ...interface{}) (string, error) {
prec, err := cast.ToIntE(precision)
if err != nil {
return "", err
}
n, err := cast.ToFloat64E(number)
if err != nil {
return "", err
}
var neg, dec, grp string
if len(options) == 0 {
// TODO(moorereason): move to site config
neg, dec, grp = "-", ".", ","
} else {
s, err := cast.ToStringE(options[0])
if err != nil {
return "", nil
}
rs := strings.Fields(s)
switch len(rs) {
case 0:
case 1:
neg = rs[0]
case 2:
neg, dec = rs[0], rs[1]
case 3:
neg, dec, grp = rs[0], rs[1], rs[2]
default:
return "", errors.New("too many fields in options parameter to NumFmt")
}
}
// Logic from MIT Licensed github.com/go-playground/locales/
// Original Copyright (c) 2016 Go Playground
s := strconv.FormatFloat(math.Abs(n), 'f', prec, 64)
L := len(s) + 2 + len(s[:len(s)-1-prec])/3
var count int
inWhole := prec == 0
b := make([]byte, 0, L)
for i := len(s) - 1; i >= 0; i-- {
if s[i] == '.' {
for j := len(dec) - 1; j >= 0; j-- {
b = append(b, dec[j])
}
inWhole = true
continue
}
if inWhole {
if count == 3 {
for j := len(grp) - 1; j >= 0; j-- {
b = append(b, grp[j])
}
count = 1
} else {
count++
}
}
b = append(b, s[i])
}
if n < 0 {
for j := len(neg) - 1; j >= 0; j-- {
b = append(b, neg[j])
}
}
// reverse
for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
b[i], b[j] = b[j], b[i]
}
return string(b), nil
}