using iframe to manage upload of schemas - allows for calling an action listener once the upload is complete to validate the schema and present an error message inside the form in a pretty way.

added a small helper library for managing uploads without using a page reload.  modified uploadfileservlet to return a javascript snippet in the response body if the return-page parameter starts with javascript:

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@4578 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/web/app/servlet/UploadFileServlet.java

@@ -18,6 +18,7 @@ package org.alfresco.web.app.servlet;
 
 import java.io.File;
 import java.io.IOException;
+import java.io.PrintWriter;
 import java.util.Iterator;
 import java.util.List;
 
@@ -47,7 +48,7 @@ import org.apache.commons.logging.LogFactory;
 public class UploadFileServlet extends BaseServlet
 {
    private static final long serialVersionUID = -5482538466491052873L;
-   private static Log logger = LogFactory.getLog(UploadFileServlet.class); 
+   private static final Log logger = LogFactory.getLog(UploadFileServlet.class); 
    
    /**
     * @see javax.servlet.http.HttpServlet#service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
@@ -68,7 +69,7 @@ public class UploadFileServlet extends BaseServlet
             return;
          }
          
-         if (isMultipart == false)
+         if (!isMultipart)
          {
             throw new AlfrescoRuntimeException("This servlet can only be used to handle file upload requests, make" +
                                         "sure you have set the enctype attribute on your form to multipart/form-data");
@@ -85,11 +86,9 @@ public class UploadFileServlet extends BaseServlet
          
          List<FileItem> fileItems = upload.parseRequest(request);
          
-         Iterator<FileItem> iter = fileItems.iterator();
          FileUploadBean bean = new FileUploadBean();
-         while(iter.hasNext())
+         for (FileItem item : fileItems)
          {
-            FileItem item = iter.next();
             if(item.isFormField())
             {
                if (item.getFieldName().equalsIgnoreCase("return-page"))
@@ -106,15 +105,13 @@ public class UploadFileServlet extends BaseServlet
                String filename = item.getName();
                if (filename != null && filename.length() != 0)
                {
-                  if (logger.isDebugEnabled() == true)
+                  if (logger.isDebugEnabled())
                   {
                      logger.debug("Processing uploaded file: " + filename);
                   }
-                  
                   // workaround a bug in IE where the full path is returned
                   // IE is only available for Windows so only check for the Windows path separator
                   int idx = filename.lastIndexOf('\\');
-                  
                   if (idx == -1)
                   {
                      // if there is no windows path separator check for *nix
@@ -131,8 +128,7 @@ public class UploadFileServlet extends BaseServlet
                   bean.setFile(tempFile);
                   bean.setFileName(filename);
                   bean.setFilePath(tempFile.getAbsolutePath());
-                  session.setAttribute(FileUploadBean.getKey(uploadId), bean);
-                  if (logger.isDebugEnabled() == true)
+                  if (logger.isDebugEnabled())
                   {
                      logger.debug("Temp file: " + tempFile.getAbsolutePath() + 
 				  " created from upload filename: " + filename);
@@ -140,19 +136,39 @@ public class UploadFileServlet extends BaseServlet
                }
             }
          }
-         
+
+         session.setAttribute(FileUploadBean.getKey(uploadId), bean);         
+
          if (returnPage == null || returnPage.length() == 0)
          {
             throw new AlfrescoRuntimeException("return-page parameter has not been supplied");
          }
-
-         // finally redirect
-         if (logger.isDebugEnabled() == true)
+         
+         if (returnPage.startsWith("javascript:"))
          {
-            logger.debug("Upload servicing complete, redirecting to: " + returnPage);
-         }
+            returnPage = returnPage.substring("javascript:".length());
+            // finally redirect
+            if (logger.isDebugEnabled())
+            {
+               logger.debug("Sending back javascript response " + returnPage);
+            }
 
-         response.sendRedirect(returnPage);
+            final PrintWriter out = response.getWriter();
+            out.println("<html><body><script type=\"text/javascript\">");
+            out.println(returnPage);
+            out.println("</script></body></html>");
+            out.close();
+         }
+         else
+         {
+            // finally redirect
+            if (logger.isDebugEnabled())
+            {
+               logger.debug("Upload servicing complete, redirecting to: " + returnPage);
+            }
+            
+            response.sendRedirect(returnPage);
+         }
       }
       catch (Throwable error)
       {

source/java/org/alfresco/web/bean/wcm/CreateFormWizard.java

@@ -465,7 +465,7 @@ public class CreateFormWizard
       // refresh the current page
       return null;
    }
-   
+    
    /**
     * Action handler called when the user wishes to remove an uploaded file
     */
@@ -488,6 +488,25 @@ public class CreateFormWizard
       return null;
    }
    
+   public String validateSchema()
+   {
+      if (this.getSchemaFile() != null)
+      {
+         final FormsService ts = FormsService.getInstance();
+         try
+         {
+            final Document d = ts.parseXML(this.getSchemaFile());
+            final XSModel xsm = SchemaUtil.loadSchema(d);
+         }
+         catch (Exception e)
+         {
+            final String msg = "unable to parse " + this.getSchemaFileName();
+            this.removeUploadedSchemaFile();
+            Utils.addErrorMessage(msg, e);
+         }
+      }
+      return null;
+   }
    
    // ------------------------------------------------------------------------------
    // Bean Getters and Setters
@@ -693,7 +712,6 @@ public class CreateFormWizard
             final String msg = "unable to parse " + this.getSchemaFileName();
             this.removeUploadedSchemaFile();
             Utils.addErrorMessage(msg, e);
-            throw new AlfrescoRuntimeException(msg, e);
          }
       }
       return result;

source/java/org/alfresco/web/ui/common/renderer/ActionLinkRenderer.java

@@ -75,29 +75,29 @@ public class ActionLinkRenderer extends BaseRenderer
    public void encodeEnd(FacesContext context, UIComponent component) throws IOException
    {
       // always check for this flag - as per the spec
-      if (component.isRendered() == true)
+      if (!component.isRendered())
       {
-         Writer out = context.getResponseWriter();
+         return;
+      }
+      Writer out = context.getResponseWriter();
+      UIActionLink link = (UIActionLink)component;
          
-         UIActionLink link = (UIActionLink)component;
-         
-         UIComponent verticalContiner = getVerticalContainer(link);
-         if (verticalContiner != null)
-         {
-            int padding = link.getPadding();
+      UIComponent verticalContiner = getVerticalContainer(link);
+      if (verticalContiner != null)
+      {
+         int padding = link.getPadding();
             
-            if (verticalContiner instanceof UIActions)
-            {
-               padding = ((UIActions)verticalContiner).getVerticalSpacing();
-            }
-            // render as menu item style action link
-            out.write( renderMenuAction(context, link, padding) );
-         }
-         else
+         if (verticalContiner instanceof UIActions)
          {
-            // render as action link
-            out.write( renderActionLink(context, link) );
+            padding = ((UIActions)verticalContiner).getVerticalSpacing();
          }
+         // render as menu item style action link
+         out.write( renderMenuAction(context, link, padding) );
+      }
+      else
+      {
+         // render as action link
+         out.write( renderActionLink(context, link) );
       }
    }
    
@@ -190,6 +190,12 @@ public class ActionLinkRenderer extends BaseRenderer
             }
          }
          
+         if (attrs.get("id") != null)
+         {
+            linkBuf.append(" id=\"")
+                   .append(attrs.get("id"))
+                   .append("\"");
+         }    
          if (attrs.get("style") != null)
          {
             linkBuf.append(" style=\"")

source/web/jsp/wcm/create-form-wizard/details.jsp

@@ -19,8 +19,13 @@
 <%@ taglib uri="/WEB-INF/alfresco.tld" prefix="a" %>
 <%@ taglib uri="/WEB-INF/repo.tld" prefix="r" %>
 <%@ page import="org.alfresco.web.bean.FileUploadBean" %>
+<%@ page import="org.alfresco.web.bean.wcm.CreateFormWizard" %>
 <f:verbatim>
-<script type="text/javascript" src="<%=request.getContextPath()%>/scripts/validation.js">
+<script type="text/javascript" 
+	src="<%=request.getContextPath()%>/scripts/validation.js">
+</script>
+<script type="text/javascript" 
+	src="<%=request.getContextPath()%>/scripts/upload_helper.js">
 </script>
 
 <script type="text/javascript">
@@ -29,7 +34,7 @@
    
    function pageLoaded()
    {
-//      document.getElementById("wizard:wizard-body:file-name").focus();
+      document.getElementById("wizard:wizard-body:file-input").focus();
       document.getElementById("wizard").onsubmit = validate;
       document.getElementById("wizard:next-button").onclick = function() {finishButtonPressed = true; clear_wizard();}
       document.getElementById("wizard:finish-button").onclick = function() {finishButtonPressed = true; clear_wizard();}
@@ -37,17 +42,22 @@
    
    function validate()
    {
-	return true;
+     return true;
+   }
+   
+   function handle_upload(target)
+   {
+     handle_upload_helper(target, 
+                          "<%= CreateFormWizard.FILE_SCHEMA %>", 
+                          upload_complete,
+                          "<%= request.getContextPath() %>")
    }
 
-   function upload_file(el)
+   function upload_complete(id, path)
    {
-     el.form.method = "post";
-     el.form.encType = "multipart/form-data";
-     // for IE
-     el.form.encoding = "multipart/form-data";
-     el.form.action = "<%= request.getContextPath() %>/uploadFileServlet";
-     el.form.submit();
+     var validate_button = 
+       document.getElementById("wizard:wizard-body:command_button_validate_schema");
+     validate_button.click();
    }
 </script>
 </f:verbatim>
@@ -75,15 +85,23 @@
     <h:column id="column_schema">
 <%
 FileUploadBean upload = (FileUploadBean)
-   session.getAttribute(FileUploadBean.getKey("schema"));
+   session.getAttribute(FileUploadBean.getKey(CreateFormWizard.FILE_SCHEMA));
 if (upload == null || upload.getFile() == null)
 {
 %>
       <f:verbatim>
-        <input type="hidden" name="upload-id" value="schema"/>
-        <input type="hidden" name="return-page" value="<%= request.getContextPath() %>/faces<%= request.getServletPath() %>"/>
-        <input id="wizard:wizard-body:file-input" type="file" size="35" name="alfFileInput" onchange="javascript:upload_file(this)"/>
+        <input id="wizard:wizard-body:file-input" 
+	       type="file" 
+	       size="35" 
+	       name="alfFileInput" 
+	       onchange="javascript:handle_upload(this)"/>
       </f:verbatim>
+      <h:commandButton id="command_button_validate_schema" 
+		       value="" 
+		       immediate="true"
+		       style="display: none"
+		       action="#{WizardManager.bean.validateSchema}"/>
+
 <%
 } else {
 %>

source/web/scripts/upload_helper.js

@@ -0,0 +1,50 @@
+var _uploads = [];
+
+function handle_upload_helper(fileInputElement,
+                              uploadId,
+                              callback,
+                              contextPath)
+{
+  var id = fileInputElement.getAttribute("name");
+  var d = fileInputElement.ownerDocument;
+  var iframe = d.createElement("iframe");
+  iframe.style.display = "none";
+  iframe.name = id + "upload_frame";
+  iframe.id = iframe.name;
+  document.body.appendChild(iframe);
+
+  // makes it possible to target the frame properly in ie.
+  window.frames[iframe.name].name = iframe.name;
+
+  _uploads[uploadId] = { path: fileInputElement.value, callback: callback };
+
+  var form = d.createElement("form");
+  d.body.appendChild(form);
+  form.style.display = "none";
+  form.method = "post";
+  form.encoding = "multipart/form-data";
+  form.enctype = "multipart/form-data";
+  form.target = iframe.name;
+  form.action = contextPath + "/uploadFileServlet";
+  form.appendChild(fileInputElement.cloneNode(true));
+
+  var id = document.createElement("input");
+  form.appendChild(id);
+  id.type = "hidden";
+  id.name = "upload-id";
+  id.value = uploadId;
+
+  var rp = document.createElement("input");
+  form.appendChild(rp);
+  rp.type = "hidden";
+  rp.name = "return-page";
+  rp.value = "javascript:window.parent.upload_complete_helper('" + uploadId + "')";
+
+  form.submit();
+}
+
+function upload_complete_helper(id)
+{
+  var upload = _uploads[id];
+  upload.callback(id, upload.path);
+}