First cut of the AJAX framework

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@3327 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/web/bean/ajax/BaseAjaxBean.java

@@ -0,0 +1,51 @@
+package org.alfresco.web.bean.ajax;
+
+import java.io.IOException;
+
+import javax.faces.context.FacesContext;
+import javax.faces.context.ResponseWriter;
+
+/**
+ * Base class for all Ajax managed beans.
+ * 
+ * It is not necessary to extend this bean but it provides 
+ * helper methods.
+ * 
+ * @author gavinc
+ */
+public abstract class BaseAjaxBean
+{
+   private ResponseWriter writer;
+   
+   /**
+    * Writes the given string to the response writer for this bean
+    * 
+    * @param str The string to send back to the client
+    */
+   public void write(String str)
+   {
+      try
+      {
+         getWriter().write(str);
+      }
+      catch (IOException ioe)
+      {
+         // not much we can do here, ignore
+      }
+   }
+   
+   /**
+    * Returns the ResponseWriter for this bean
+    * 
+    * @return The JSF ResponseWriter
+    */
+   public ResponseWriter getWriter()
+   {
+      if (this.writer == null)
+      {
+         this.writer = FacesContext.getCurrentInstance().getResponseWriter();
+      }
+      
+      return this.writer;
+   }
+}