Add backend post handling, endpoints, rendering

postrender.go

@@ -2,9 +2,12 @@ package writefreely
 
 import (
 	"bytes"
+	"fmt"
 	"github.com/microcosm-cc/bluemonday"
 	stripmd "github.com/writeas/go-strip-markdown"
 	"github.com/writeas/saturday"
+	"github.com/writeas/web-core/stringmanip"
+	"github.com/writeas/writefreely/parse"
 	"html"
 	"html/template"
 	"regexp"
@@ -122,6 +125,30 @@ func postTitle(content, friendlyId string) string {
 	return friendlyId
 }
 
+// TODO: fix duplicated code from postTitle. postTitle is a widely used func we
+// don't have time to investigate right now.
+func friendlyPostTitle(content, friendlyId string) string {
+	const maxTitleLen = 80
+
+	// Strip HTML tags with bluemonday's StrictPolicy, then unescape the HTML
+	// entities added in by sanitizing the content.
+	content = html.UnescapeString(bluemonday.StrictPolicy().Sanitize(content))
+
+	content = strings.TrimLeftFunc(stripmd.Strip(content), unicode.IsSpace)
+	eol := strings.IndexRune(content, '\n')
+	blankLine := strings.Index(content, "\n\n")
+	if blankLine != -1 && blankLine <= eol && blankLine <= assumedTitleLen {
+		return strings.TrimSpace(content[:blankLine])
+	} else if eol == -1 && utf8.RuneCountInString(content) <= maxTitleLen {
+		return content
+	}
+	title, truncd := parse.TruncToWord(parse.PostLede(content, true), maxTitleLen)
+	if truncd {
+		title += "..."
+	}
+	return title
+}
+
 func getSanitizationPolicy() *bluemonday.Policy {
 	policy := bluemonday.UGCPolicy()
 	policy.AllowAttrs("src", "style").OnElements("iframe", "video")
@@ -133,3 +160,62 @@ func getSanitizationPolicy() *bluemonday.Policy {
 	policy.AllowURLSchemes("http", "https", "mailto", "xmpp")
 	return policy
 }
+
+func sanitizePost(content string) string {
+	return strings.Replace(content, "<", "&lt;", -1)
+}
+
+// postDescription generates a description based on the given post content,
+// title, and post ID. This doesn't consider a V2 post field, `title` when
+// choosing what to generate. In case a post has a title, this function will
+// fail, and logic should instead be implemented to skip this when there's no
+// title, like so:
+//    var desc string
+//    if title == "" {
+//        desc = postDescription(content, title, friendlyId)
+//    } else {
+//        desc = shortPostDescription(content)
+//    }
+func postDescription(content, title, friendlyId string) string {
+	maxLen := 140
+
+	if content == "" {
+		content = "Write Freely is a painless, simple, federated blogging platform."
+	} else {
+		fmtStr := "%s"
+		truncation := 0
+		if utf8.RuneCountInString(content) > maxLen {
+			// Post is longer than the max description, so let's show a better description
+			fmtStr = "%s..."
+			truncation = 3
+		}
+
+		if title == friendlyId {
+			// No specific title was found; simply truncate the post, starting at the beginning
+			content = fmt.Sprintf(fmtStr, strings.Replace(stringmanip.Substring(content, 0, maxLen-truncation), "\n", " ", -1))
+		} else {
+			// There was a title, so return a real description
+			blankLine := strings.Index(content, "\n\n")
+			if blankLine < 0 {
+				blankLine = 0
+			}
+			truncd := stringmanip.Substring(content, blankLine, blankLine+maxLen-truncation)
+			contentNoNL := strings.Replace(truncd, "\n", " ", -1)
+			content = strings.TrimSpace(fmt.Sprintf(fmtStr, contentNoNL))
+		}
+	}
+
+	return content
+}
+
+func shortPostDescription(content string) string {
+	maxLen := 140
+	fmtStr := "%s"
+	truncation := 0
+	if utf8.RuneCountInString(content) > maxLen {
+		// Post is longer than the max description, so let's show a better description
+		fmtStr = "%s..."
+		truncation = 3
+	}
+	return strings.TrimSpace(fmt.Sprintf(fmtStr, strings.Replace(stringmanip.Substring(content, 0, maxLen-truncation), "\n", " ", -1)))
+}