hugo/hugolib/shortcode.go

// Copyright © 2013 Steve Francia <spf@spf13.com>.
//
// Licensed under the Simple Public 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://opensource.org/licenses/Simple-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 hugolib

import (
	"bytes"
	"fmt"
	"github.com/spf13/hugo/template/bundle"
	"html/template"
	"strings"
	"unicode"
)

var _ = fmt.Println

type ShortcodeFunc func([]string) string

type Shortcode struct {
	Name string
	Func ShortcodeFunc
}

type ShortcodeWithPage struct {
	Params interface{}
	Inner  template.HTML
	Page   *Page
}

type Shortcodes map[string]ShortcodeFunc

func ShortcodesHandle(stringToParse string, p *Page, t bundle.Template) string {
	leadStart := strings.Index(stringToParse, `{{%`)
	if leadStart >= 0 {
		leadEnd := strings.Index(stringToParse[leadStart:], `%}}`) + leadStart
		if leadEnd > leadStart {
			name, par := SplitParams(stringToParse[leadStart+3 : leadEnd])
			tmpl := GetTemplate(name, t)
			if tmpl == nil {
				return stringToParse
			}
			params := Tokenize(par)
			// Always look for closing tag.
			endStart, endEnd := FindEnd(stringToParse[leadEnd:], name)
			var data = &ShortcodeWithPage{Params: params, Page: p}
			if endStart > 0 {
				s := stringToParse[leadEnd+3 : leadEnd+endStart]
				data.Inner = template.HTML(CleanP(ShortcodesHandle(s, p, t)))
				remainder := CleanP(stringToParse[leadEnd+endEnd:])

				return CleanP(stringToParse[:leadStart]) +
					ShortcodeRender(tmpl, data) +
					CleanP(ShortcodesHandle(remainder, p, t))
			}
			return CleanP(stringToParse[:leadStart]) +
				ShortcodeRender(tmpl, data) +
				CleanP(ShortcodesHandle(stringToParse[leadEnd+3:], p,
					t))
		}
	}
	return stringToParse
}

// Clean up odd behavior when closing tag is on first line
// or opening tag is on the last line due to extra line in markdown file
func CleanP(str string) string {
	if strings.HasSuffix(strings.TrimSpace(str), "<p>") {
		idx := strings.LastIndex(str, "<p>")
		str = str[:idx]
	}

	if strings.HasPrefix(strings.TrimSpace(str), "</p>") {
		str = str[strings.Index(str, "</p>")+5:]
	}

	return str
}

func FindEnd(str string, name string) (int, int) {
	var endPos int
	var startPos int
	var try []string

	try = append(try, "{{% /"+name+" %}}")
	try = append(try, "{{% /"+name+"%}}")
	try = append(try, "{{%/"+name+"%}}")
	try = append(try, "{{%/"+name+" %}}")

	lowest := len(str)
	for _, x := range try {
		start := strings.Index(str, x)
		if start < lowest && start > 0 {
			startPos = start
			endPos = startPos + len(x)
		}
	}

	return startPos, endPos
}

func GetTemplate(name string, t bundle.Template) *template.Template {
	if x := t.Lookup("shortcodes/" + name + ".html"); x != nil {
		return x
	}
	return t.Lookup("_internal/shortcodes/" + name + ".html")
}

func StripShortcodes(stringToParse string) string {
	posStart := strings.Index(stringToParse, "{{%")
	if posStart > 0 {
		posEnd := strings.Index(stringToParse[posStart:], "%}}") + posStart
		if posEnd > posStart {
			newString := stringToParse[:posStart] + StripShortcodes(stringToParse[posEnd+3:])
			return newString
		}
	}
	return stringToParse
}

func Tokenize(in string) interface{} {
	first := strings.Fields(in)
	var final = make([]string, 0)

	// if don't need to parse, don't parse.
	if strings.Index(in, " ") < 0 && strings.Index(in, "=") < 1 {
		return append(final, in)
	}

	var keys = make([]string, 0)
	inQuote := false
	start := 0

	for i, v := range first {
		index := strings.Index(v, "=")

		if index < 0 {
			fmt.Printf("Shortcode parameters must be key=value pairs (no spaces) (saw '%s')\n", v)
			continue
		}

		if !inQuote {
			if index > 1 {
				keys = append(keys, v[:index])
				v = v[index+1:]
			}
		}

		// Adjusted to handle htmlencoded and non htmlencoded input
		if !strings.HasPrefix(v, "&ldquo;") && !strings.HasPrefix(v, "\"") && !inQuote {
			final = append(final, v)
		} else if inQuote && (strings.HasSuffix(v, "&rdquo;") ||
			strings.HasSuffix(v, "\"")) && !strings.HasSuffix(v, "\\\"") {
			if strings.HasSuffix(v, "\"") {
				first[i] = v[:len(v)-1]
			} else {
				first[i] = v[:len(v)-7]
			}
			final = append(final, strings.Join(first[start:i+1], " "))
			inQuote = false
		} else if (strings.HasPrefix(v, "&ldquo;") ||
			strings.HasPrefix(v, "\"")) && !inQuote {
			if strings.HasSuffix(v, "&rdquo;") || strings.HasSuffix(v,
				"\"") {
				if strings.HasSuffix(v, "\"") {
					if len(v) > 1 {
						final = append(final, v[1:len(v)-1])
					} else {
						final = append(final, "")
					}
				} else {
					final = append(final, v[7:len(v)-7])
				}
			} else {
				start = i
				if strings.HasPrefix(v, "\"") {
					first[i] = v[1:]
				} else {
					first[i] = v[7:]
				}
				inQuote = true
			}
		}

		// No closing "... just make remainder the final token
		if inQuote && i == len(first) {
			final = append(final, first[start:]...)
		}
	}

	if len(keys) > 0 && (len(keys) != len(final)) {
		panic("keys and final different lengths")
	}

	if len(keys) > 0 {
		var m = make(map[string]string)
		for i, k := range keys {
			m[k] = final[i]
		}

		return m
	}

	return final
}

func SplitParams(in string) (name string, par2 string) {
	i := strings.IndexFunc(strings.TrimSpace(in), unicode.IsSpace)
	if i < 1 {
		return strings.TrimSpace(in), ""
	}

	return strings.TrimSpace(in[:i+1]), strings.TrimSpace(in[i+1:])
}

func ShortcodeRender(tmpl *template.Template, data *ShortcodeWithPage) string {
	buffer := new(bytes.Buffer)
	err := tmpl.Execute(buffer, data)
	if err != nil {
		fmt.Println("error processing shortcode", tmpl.Name(), "\n ERR:", err)
	}
	return buffer.String()
}