Wordpress Shortcodes in Golang

wp-shortcodes.go

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"regexp"
	"strconv"
	"strings"
)

func main() {
	output, _ := doShortcode(`tests fasdf [getremote url="http://outerplex.com" limit="3"] a a sdfsadf asf as [getremote url="http://sureplex.com" limit="4"] asd fadsf`)
	fmt.Println(output)
}

func doShortcode(input string) (string, error) {
	type attributes struct {
		url   string
		limit int
	}

	matchShortcodeParametersRegex, _ := regexp.Compile(`([a-zA-Z]+)="([^"]+)+"`)

	matchShortcodesRegex, _ := regexp.Compile(`\[getremote*.*?\]`)
	shortcodes := matchShortcodesRegex.FindAllString(input, -1)

	// input := `tests fasdf %v a a sdfsadf asf as %v asd fadsf`

	var results []interface{}

	for _, shortcode := range shortcodes {

		// shortcode = [getremote url="http://outerplex.com" limit="3"]

		parseAttrs := matchShortcodeParametersRegex.FindAllString(shortcode, -1)
		attrs := &attributes{}

		for _, attr := range parseAttrs {
			keyValue := strings.Split(attr, "=")
			key := keyValue[0]

			value := keyValue[1]
			value = strings.Replace(value, `"`, ``, -1)

			if key == "url" {
				attrs.url = value
			}

			if key == "limit" {
				i, _ := strconv.Atoi(value)
				attrs.limit = i
			}
		}

		// If this fails, let's cancel the email and try again later
		// the endpoint is not available and we don't want to send without this content

		// TODO: Verify response headers to prevent malicious remote file downloads
		response, err := http.Get(attrs.url)
		if err != nil {
			return input, err
		}

		defer response.Body.Close()
		contents, err := ioutil.ReadAll(response.Body)
		if err != nil {
			return input, err
		}

		results = append(results, string(contents))
	}

	input = matchShortcodesRegex.ReplaceAllString(input, "%v")
	return fmt.Sprintf(input, results...), nil
}

/*

The MIT License (MIT)

Copyright (c) 2018 Tim Badolato and Contributors

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

*/