hugo/tpl/transform/transform.go

125 lines
3.2 KiB
Go
Raw Normal View History

// 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 transform
import (
"bytes"
"html"
"html/template"
"github.com/gohugoio/hugo/deps"
"github.com/gohugoio/hugo/helpers"
"github.com/spf13/cast"
)
// New returns a new instance of the transform-namespaced template functions.
func New(deps *deps.Deps) *Namespace {
return &Namespace{
deps: deps,
}
}
// Namespace provides template functions for the "transform" namespace.
type Namespace struct {
deps *deps.Deps
}
// Emojify returns a copy of s with all emoji codes replaced with actual emojis.
//
// See http://www.emoji-cheat-sheet.com/
func (ns *Namespace) Emojify(s interface{}) (template.HTML, error) {
ss, err := cast.ToStringE(s)
if err != nil {
return "", err
}
return template.HTML(helpers.Emojify([]byte(ss))), nil
}
// Highlight returns a copy of s as an HTML string with syntax
// highlighting applied.
func (ns *Namespace) Highlight(s interface{}, lang, opts string) (template.HTML, error) {
ss, err := cast.ToStringE(s)
if err != nil {
return "", err
}
highlighted, _ := ns.deps.ContentSpec.Highlight(ss, lang, opts)
return template.HTML(highlighted), nil
}
// HTMLEscape returns a copy of s with reserved HTML characters escaped.
func (ns *Namespace) HTMLEscape(s interface{}) (string, error) {
ss, err := cast.ToStringE(s)
if err != nil {
return "", err
}
return html.EscapeString(ss), nil
}
// HTMLUnescape returns a copy of with HTML escape requences converted to plain
// text.
func (ns *Namespace) HTMLUnescape(s interface{}) (string, error) {
ss, err := cast.ToStringE(s)
if err != nil {
return "", err
}
return html.UnescapeString(ss), nil
}
var (
markdownTrimPrefix = []byte("<p>")
markdownTrimSuffix = []byte("</p>\n")
markdownParagraphIndicator = []byte("<p")
)
// Markdownify renders a given input from Markdown to HTML.
func (ns *Namespace) Markdownify(s interface{}) (template.HTML, error) {
ss, err := cast.ToStringE(s)
if err != nil {
return "", err
}
m := ns.deps.ContentSpec.RenderBytes(
&helpers.RenderingContext{
Cfg: ns.deps.Cfg,
Content: []byte(ss),
PageFmt: "markdown",
Config: ns.deps.ContentSpec.BlackFriday,
},
)
// Strip if this is a short inline type of text.
first := bytes.Index(m, markdownParagraphIndicator)
last := bytes.LastIndex(m, markdownParagraphIndicator)
if first == last {
m = bytes.TrimPrefix(m, markdownTrimPrefix)
m = bytes.TrimSuffix(m, markdownTrimSuffix)
}
return template.HTML(m), nil
}
// Plainify returns a copy of s with all HTML tags removed.
func (ns *Namespace) Plainify(s interface{}) (string, error) {
ss, err := cast.ToStringE(s)
if err != nil {
return "", err
}
return helpers.StripHTML(ss), nil
}