Add html truncating

pkg/gctemplates/funcs.go

@@ -109,6 +109,7 @@ var funcMap = template.FuncMap{
 		}
 		return msg
 	},
+	"truncateHTMLMessage": truncateHTML,
 	"stripHTML": func(htmlStr template.HTML) string {
 		dom := x_html.NewTokenizer(strings.NewReader(string(htmlStr)))
 		for tokenType := dom.Next(); tokenType != x_html.ErrorToken; {

pkg/gctemplates/misc.go

@@ -0,0 +1,76 @@
+package gctemplates
+
+import (
+	"bytes"
+	"html/template"
+	"strings"
+
+	"github.com/gochan-org/gochan/pkg/gclog"
+	x_html "golang.org/x/net/html"
+)
+
+//TruncateHTML truncates a template.HTML string to a certain visible character limit and line limit
+func truncateHTML(htmlText template.HTML, characterLimit int, maxLines int) template.HTML {
+	dom, err := x_html.Parse(strings.NewReader(string(htmlText)))
+	if err != nil {
+		gclog.Println(gclog.LErrorLog, err.Error())
+		return template.HTML("Server error truncating HTML, failed to parse html")
+	}
+	truncateHTMLNodes(dom, characterLimit, maxLines)
+	buf := new(bytes.Buffer)
+	x_html.Render(buf, dom)
+	return template.HTML(buf.String())
+}
+
+func removeNextSiblings(node *x_html.Node) {
+	if node == nil {
+		return
+	}
+	removeNextSiblings(node.NextSibling)
+	node.Parent.RemoveChild(node)
+}
+
+func truncateHTMLNodes(node *x_html.Node, charactersLeft int, linesLeft int) (charsLeft int, lineLeft int) {
+	//Uses a depth first search to map nodes and remove the rest.
+
+	if node == nil {
+		return charactersLeft, linesLeft
+	}
+
+	//if either value is 0 or less, remove next siblings and self
+	if charactersLeft <= 0 || linesLeft <= 0 {
+		removeNextSiblings(node)
+	}
+
+	switch node.Type {
+	case x_html.ElementNode:
+		//This is a tag node. If tag node is br, redude amount of lines by 1
+		if strings.ToLower(node.Data) == "br" {
+			linesLeft--
+		}
+		//Acts as normal node for the rest
+		fallthrough
+	case x_html.CommentNode:
+		fallthrough
+	case x_html.DoctypeNode:
+		fallthrough
+	case x_html.RawNode:
+		fallthrough
+	case x_html.ErrorNode:
+		fallthrough
+	case x_html.DocumentNode:
+		//None of the nodes directly contain text
+		//truncate children first
+		charactersLeft, linesLeft = truncateHTMLNodes(node.FirstChild, charactersLeft, linesLeft)
+		//Pass values to siblings (sibling code will immediately exit if no more chars allowed, and remove self)
+		return truncateHTMLNodes(node.NextSibling, charactersLeft, linesLeft)
+	case x_html.TextNode:
+		if len(node.Data) > charactersLeft {
+			node.Data = node.Data[0:charactersLeft-1] + "\n..."
+		}
+		charactersLeft -= len(node.Data)
+		return truncateHTMLNodes(node.NextSibling, charactersLeft, linesLeft)
+	}
+	gclog.Println(gclog.LErrorLog, "Did not match any known node type, possible error?: ", node)
+	return charactersLeft, linesLeft
+}

templates/boardpage.html

@@ -22,7 +22,7 @@
 				{{end}}
 			{{end}}
 			<input type="checkbox" id="check{{$op.ID}}" name="check{{$op.ID}}" /><label class="post-info" for="check{{$op.ID}}"> <span class="subject">{{$op.Subject}}</span> <span class="postername">{{if ne $op.Email ""}}<a href="mailto:{{$op.Email}}">{{end}}{{if ne $op.Name ""}}{{$op.Name}}{{else}}{{if eq $op.Tripcode ""}}{{$.board.Anonymous}}{{end}}{{end}}{{if ne $op.Email ""}}</a>{{end}}</span>{{if ne $op.Tripcode ""}}<span class="tripcode">!{{$op.Tripcode}}</span>{{end}} {{formatTimestamp $op.Timestamp}} </label><a href="{{$.config.SiteWebfolder}}{{$.board.Dir}}/res/{{$op.ID}}.html#{{$op.ID}}">No.</a> <a href="javascript:quote({{$op.ID}})" class="backlink-click">{{$op.ID}}</a> <span class="post-links"> <span class="thread-ddown">[<a href="javascript:void(0)">&#9660;</a>]</span> <span>[<a href="{{$.config.SiteWebfolder}}{{$.board.Dir}}/res/{{$op.ID}}.html">View</a>]</span></span><br />
-			<div class="post-text">{{truncateMessage $op.MessageHTML 2222 18}}</div>
+			<div class="post-text">{{truncateHTMLMessage $op.MessageHTML 2222 18}}</div>
 			{{- if gt $thread.NumReplies 3}}
 				<b>{{subtract $thread.NumReplies 3}} post{{if gt $thread.NumReplies 4}}s{{end}} omitted</b>
 			{{end}}