From 1ad0ca51d5c2e7682a136c8cf53bafc55cb98a49 Mon Sep 17 00:00:00 2001
From: Frederic Ye <frederic.ye@mlstate.com>
Date: Tue, 18 Oct 2011 19:13:01 +0200
Subject: [PATCH] [enhance] xhtml.opa: added a function to update an xhtml
 attribute by appending a new value to it (usefull for updating class
 attribute especially)

---
 stdlib/core/xhtml/xhtml.opa | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/stdlib/core/xhtml/xhtml.opa b/stdlib/core/xhtml/xhtml.opa
index 64da89cf..9efd9182 100644
--- a/stdlib/core/xhtml/xhtml.opa
+++ b/stdlib/core/xhtml/xhtml.opa
@@ -1155,6 +1155,25 @@ Xhtml =
     end
     aux(x)
 
+  /**
+   * Update (by appending) an attribute to an xhtml node, add it if not already present
+   */
+  update_attribute(name: string, value: string, x:xhtml):xhtml =
+    rec aux(x)=
+    match x : xhtml
+    {fragment=[x]} -> aux(x)
+    {~args namespace=_ tag=_ content=_ specific_attributes=_} as x->
+      args = match find_attr(name,args) with
+             {some=val} ->
+               value = "{val} {value}"
+               l = remove_attr(name,args)
+               [{~name namespace="" ~value}|l]
+             {none} -> [{~name namespace="" ~value}|args]
+      @opensums({x with ~args})
+    _ -> x
+    end
+    aux(x)
+
   /**
    * Set an attribute to an xhtml node. Replace if already_exists
    */