hugo/tpl/strings/truncate.go
Jorin Vogel 81c13171a9 Add some missing doc comments
As pointed out by the linter, some exported functions and types are
missing doc comments.
The linter warnings have been reduced from 194 to 116.
Not all missing comments have been added in this commit though.
2017-08-03 15:57:51 +02:00

157 lines
3.7 KiB
Go

// Copyright 2016 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 strings
import (
"errors"
"html"
"html/template"
"regexp"
"unicode"
"unicode/utf8"
"github.com/spf13/cast"
)
var (
tagRE = regexp.MustCompile(`^<(/)?([^ ]+?)(?:(\s*/)| .*?)?>`)
htmlSinglets = map[string]bool{
"br": true, "col": true, "link": true,
"base": true, "img": true, "param": true,
"area": true, "hr": true, "input": true,
}
)
type htmlTag struct {
name string
pos int
openTag bool
}
// Truncate truncates a given string to the specified length.
func (ns *Namespace) Truncate(a interface{}, options ...interface{}) (template.HTML, error) {
length, err := cast.ToIntE(a)
if err != nil {
return "", err
}
var textParam interface{}
var ellipsis string
switch len(options) {
case 0:
return "", errors.New("truncate requires a length and a string")
case 1:
textParam = options[0]
ellipsis = " …"
case 2:
textParam = options[1]
ellipsis, err = cast.ToStringE(options[0])
if err != nil {
return "", errors.New("ellipsis must be a string")
}
if _, ok := options[0].(template.HTML); !ok {
ellipsis = html.EscapeString(ellipsis)
}
default:
return "", errors.New("too many arguments passed to truncate")
}
if err != nil {
return "", errors.New("text to truncate must be a string")
}
text, err := cast.ToStringE(textParam)
if err != nil {
return "", errors.New("text must be a string")
}
_, isHTML := textParam.(template.HTML)
if utf8.RuneCountInString(text) <= length {
if isHTML {
return template.HTML(text), nil
}
return template.HTML(html.EscapeString(text)), nil
}
tags := []htmlTag{}
var lastWordIndex, lastNonSpace, currentLen, endTextPos, nextTag int
for i, r := range text {
if i < nextTag {
continue
}
if isHTML {
// Make sure we keep tag of HTML tags
slice := text[i:]
m := tagRE.FindStringSubmatchIndex(slice)
if len(m) > 0 && m[0] == 0 {
nextTag = i + m[1]
tagname := slice[m[4]:m[5]]
lastWordIndex = lastNonSpace
_, singlet := htmlSinglets[tagname]
if !singlet && m[6] == -1 {
tags = append(tags, htmlTag{name: tagname, pos: i, openTag: m[2] == -1})
}
continue
}
}
currentLen++
if unicode.IsSpace(r) {
lastWordIndex = lastNonSpace
} else if unicode.In(r, unicode.Han, unicode.Hangul, unicode.Hiragana, unicode.Katakana) {
lastWordIndex = i
} else {
lastNonSpace = i + utf8.RuneLen(r)
}
if currentLen > length {
if lastWordIndex == 0 {
endTextPos = i
} else {
endTextPos = lastWordIndex
}
out := text[0:endTextPos]
if isHTML {
out += ellipsis
// Close out any open HTML tags
var currentTag *htmlTag
for i := len(tags) - 1; i >= 0; i-- {
tag := tags[i]
if tag.pos >= endTextPos || currentTag != nil {
if currentTag != nil && currentTag.name == tag.name {
currentTag = nil
}
continue
}
if tag.openTag {
out += ("</" + tag.name + ">")
} else {
currentTag = &tag
}
}
return template.HTML(out), nil
}
return template.HTML(html.EscapeString(out) + ellipsis), nil
}
}
if isHTML {
return template.HTML(text), nil
}
return template.HTML(html.EscapeString(text)), nil
}