Render markdown

emoji.go

@@ -0,0 +1,76 @@
+// This is taken from Hugo
+//
+// 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 main
+
+import (
+	"bytes"
+	"sync"
+
+	"github.com/kyokomi/emoji"
+)
+
+var (
+	emojiInit sync.Once
+
+	emojis = make(map[string][]byte)
+
+	emojiDelim     = []byte(":")
+	emojiWordDelim = []byte(" ")
+	emojiMaxSize   int
+)
+
+func emojify(source []byte) []byte {
+	emojiInit.Do(initEmoji)
+	start := 0
+	k := bytes.Index(source[start:], emojiDelim)
+	for k != -1 {
+		j := start + k
+		upper := j + emojiMaxSize
+		if upper > len(source) {
+			upper = len(source)
+		}
+		endEmoji := bytes.Index(source[j+1:upper], emojiDelim)
+		nextWordDelim := bytes.Index(source[j:upper], emojiWordDelim)
+		if endEmoji < 0 {
+			start++
+		} else if endEmoji == 0 || (nextWordDelim != -1 && nextWordDelim < endEmoji) {
+			start += endEmoji + 1
+		} else {
+			endKey := endEmoji + j + 2
+			emojiKey := source[j:endKey]
+			if e, ok := emojis[string(emojiKey)]; ok {
+				source = append(source[:j], append(e, source[endKey:]...)...)
+			}
+			start += endEmoji
+		}
+		if start >= len(source) {
+			break
+		}
+		k = bytes.Index(source[start:], emojiDelim)
+	}
+	return source
+}
+
+func initEmoji() {
+	emojiMap := emoji.CodeMap()
+	for k, v := range emojiMap {
+		emojis[k] = []byte(v)
+		if len(k) > emojiMaxSize {
+			emojiMaxSize = len(k)
+		}
+	}
+
+}

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/go-sql-driver/mysql v1.5.0 // indirect
 	github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00 // indirect
 	github.com/kr/text v0.2.0 // indirect
+	github.com/kyokomi/emoji v2.2.4+incompatible
 	github.com/labstack/echo/v4 v4.1.16
 	github.com/lib/pq v1.8.0 // indirect
 	github.com/lopezator/migrator v0.3.0
@@ -23,6 +24,7 @@ require (
 	github.com/spf13/viper v1.7.0
 	github.com/stretchr/testify v1.6.1 // indirect
 	github.com/valyala/fasttemplate v1.2.0 // indirect
+	github.com/yuin/goldmark v1.2.0
 	golang.org/x/crypto v0.0.0-20200709230013-948cd5f35899 // indirect
 	golang.org/x/net v0.0.0-20200707034311-ab3426394381 // indirect
 	golang.org/x/sys v0.0.0-20200728102440-3e129f6d46b1 // indirect

go.sum

@@ -122,6 +122,8 @@ github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/kyokomi/emoji v2.2.4+incompatible h1:np0woGKwx9LiHAQmwZx79Oc0rHpNw3o+3evou4BEPv4=
+github.com/kyokomi/emoji v2.2.4+incompatible/go.mod h1:mZ6aGCD7yk8j6QY6KICwnZ2pxoszVseX1DNoGtU2tBA=
 github.com/labstack/echo/v4 v4.1.16 h1:8swiwjE5Jkai3RPfZoahp8kjVCRNq+y7Q0hPji2Kz0o=
 github.com/labstack/echo/v4 v4.1.16/go.mod h1:awO+5TzAjvL8XpibdsfXxPgHr+orhtXZJZIQCVjogKI=
 github.com/labstack/gommon v0.3.0 h1:JEeO0bvc78PKdyHxloTKiF8BD5iGrH8T6MSeGvSgob0=
@@ -235,6 +237,8 @@ github.com/valyala/fasttemplate v1.1.0/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPU
 github.com/valyala/fasttemplate v1.2.0 h1:y3yXRCoDvC2HTtIHvL2cc7Zd+bqA+zqDO6oQzsJO07E=
 github.com/valyala/fasttemplate v1.2.0/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPUpymEIMZ47gx8=
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
+github.com/yuin/goldmark v1.2.0 h1:WOOcyaJPlzb8fZ8TloxFe8QZkhOOJx87leDa9MIT9dc=
+github.com/yuin/goldmark v1.2.0/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=

markdown.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"bytes"
+	_ "bytes"
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/extension"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/renderer/html"
+)
+
+var markdown goldmark.Markdown
+
+func init() {
+	markdown = goldmark.New(
+		goldmark.WithRendererOptions(
+			html.WithUnsafe(),
+		),
+		goldmark.WithParserOptions(
+			parser.WithAutoHeadingID(),
+		),
+		goldmark.WithExtensions(
+			extension.GFM,
+			extension.Footnote,
+			extension.Typographer,
+		),
+	)
+}
+
+func renderMarkdown(source string) (content string, err error) {
+	context := parser.NewContext()
+	var buffer bytes.Buffer
+	err = markdown.Convert([]byte(source), &buffer, parser.WithContext(context))
+	content = string(emojify(buffer.Bytes()))
+	return
+}

posts.go

@@ -24,7 +24,11 @@ func servePost(c echo.Context) error {
 	} else if err != nil {
 		return err
 	}
-	return c.String(http.StatusOK, post.content)
+	htmlContent, err := renderMarkdown(post.content)
+	if err != nil {
+		return err
+	}
+	return c.HTML(http.StatusOK, htmlContent)
 }
 
 func getPost(path string) (*post, error) {