add brief text to opengraph description

contrib/backends/srndv2/src/srnd/model.go

@@ -47,6 +47,7 @@ type AttachmentModel interface {
 type PostModel interface {
 	BaseModel
 
+	Brief() string
 	CSSClass() string
 	FrontendPubkey() string
 	MessageID() string

contrib/backends/srndv2/src/srnd/model_mem.go

@@ -305,6 +305,13 @@ func (self *post) Index() int {
 	return self.index + 1
 }
 
+func (self *post) Brief() string {
+	if len(self.PostMessage) > 140 {
+		return self.PostMessage[:140]
+	}
+	return self.PostMessage
+}
+
 func (self *post) NumImages() int {
 	return len(self.Files)
 }

contrib/templates/placebo/thread.mustache

@@ -24,7 +24,7 @@
         <meta property="og:site_name" content="changolia" />
         <meta property="og:type" content="website"/>
         <meta property="og:title" content="{{board.Board}}"/>
-        <meta property="og:description" content="thread no. {{thread.OP.PostHash}} on changolia"/>
+        <meta property="og:description" content="{{thread.OP.Brief}}"/>
         {{#sfw}}
         <meta property="og:url" content="{{prefix}}t/{{thread.OP.PostHash}}/?lang={{i18n.Name}}&sfw=1"/>
         {{/sfw}}