June 12, 2008 by Christoff Truter JavaScript PHP ASP.NET Visual Basic
Ever wanted to move items between two listboxes in ASP.net
(or PHP for that matter)?
Someone wanted the exact same thing on codeproject.com a while ago but I didn't give much thought
to it, until someone at work asked me how to do it - since he wasn't able to find
a viable solution on the internet.
The solution I scripted wasn't as simple as I thought, nor would have liked it to
be, my feeling was that one would be able to alter the two listboxes easily using
javascript and simply "harvest" the changes (from the Request variables) when its
submitted to the server.
The reality however is that only items selected(or highlighted) in the listboxes,
will be returned to the server, not the state of the listboxes - so we need to somehow
send the state of the listboxes along with the page request.
What I did was, I wrote a javascript script, that serialized the contents of the
listboxes as xml to a hiddenfield on the page - whenever you submit the form to
the server, a xml string containing the state of the listboxes get sent along -
which one can easily process server side (which I will show you just in a while).
function move(fromID, toID, containerID) { var from = document.getElementById(fromID); var to = document.getElementById(toID); for (var i = 0; i < from.options.length; i++) { if (from.options[i].selected) { to.options.add(new Option(from.options[i].text,from.options[i].value)) from.remove(i--); } } var container = document.getElementById(containerID); container.value = escape("<listboxes>" + serialize(from) + serialize(to) + "</listboxes>"); } function serialize(dropdown) { var value = '<' + dropdown.id + '>'; for (var i = 0; i < dropdown.options.length; i++) { value+= '<option><key><![CDATA[' + encodeURIComponent(dropdown.options[i].text) + ']]></key><value><![CDATA[' + encodeURIComponent(dropdown.options[i].value) + ']]></value></option>'; } value+='</' + dropdown.id + '>'; return value } function unselect(listbox) { document.getElementById(listbox).selectedIndex=-1; }
using System; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Xml; public partial class ListPicker : System.Web.UI.UserControl { private XmlDocument _xmlDocument = new XmlDocument(); public ListBox fromListBox { get { return lstFrom; } } public ListBox toListBox { get { return lstTo; } } private void PopulateListBox(ListBox listBox) { listBox.Items.Clear(); XmlNodeList nodes = _xmlDocument.SelectNodes("listboxes/" + listBox.ClientID + "/option"); foreach (XmlNode node in nodes) { listBox.Items.Add(new ListItem(HttpUtility.UrlDecode(node["key"].InnerText), HttpUtility.UrlDecode(node["value"].InnerText))); } } private void PopulateListBoxes() { _xmlDocument.LoadXml(HttpUtility.UrlDecode(hdnDropdowns.Value)); PopulateListBox(lstFrom); PopulateListBox(lstTo); } protected void Page_Load(object sender, EventArgs e) { Page.ClientScript.RegisterClientScriptInclude("listboxjs", Page.ResolveClientUrl("~/js/listbox.js")); if (!IsPostBack) { String movejs = "move('{0}','{1}','{2}')"; String unselectjs = "unselect('{0}')"; lstFrom.Attributes["onclick"] = String.Format(unselectjs, lstTo.ClientID); lstTo.Attributes["onclick"] = String.Format(unselectjs, lstFrom.ClientID); btnTo.Attributes["onclick"] = String.Format(movejs, lstFrom.ClientID, lstTo.ClientID, hdnDropdowns.ClientID); btnFrom.Attributes["onclick"] = String.Format(movejs, lstTo.ClientID, lstFrom.ClientID, hdnDropdowns.ClientID); } else { if (!(String.IsNullOrEmpty(hdnDropdowns.Value))) { PopulateListBoxes(); } } } }
Imports System.Xml Partial Class ListPicker Inherits System.Web.UI.UserControl Private _xmlDocument As New XmlDocument() Public ReadOnly Property fromListBox() As ListBox Get Return lstFrom End Get End Property Public ReadOnly Property toListBox() As ListBox Get Return lstTo End Get End Property Private Sub PopulateListBox(ByVal lstBox As ListBox) lstBox.Items.Clear() Dim nodes As XmlNodeList = _xmlDocument.SelectNodes("listboxes/" + lstBox.ClientID + "/option") For Each node As XmlNode In nodes lstBox.Items.Add(New ListItem(HttpUtility.UrlDecode(node.Item("key").InnerText), HttpUtility.UrlDecode(node.Item("value").InnerText))) Next End Sub Private Sub PopulateListBoxes() _xmlDocument.LoadXml(HttpUtility.UrlDecode(hdnDropdowns.Value)) PopulateListBox(lstFrom) PopulateListBox(lstTo) End Sub Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load Page.ClientScript.RegisterClientScriptInclude("listboxjs", Page.ResolveClientUrl("~/js/listbox.js")) If Not IsPostBack Then Dim movejs As String = "move('{0}','{1}','{2}')" Dim unselectjs As String = "unselect('{0}')" lstFrom.Attributes("onclick") = String.Format(unselectjs, lstTo.ClientID) lstTo.Attributes("onclick") = String.Format(unselectjs, lstFrom.ClientID) btnTo.Attributes("onclick") = String.Format(movejs, lstFrom.ClientID, lstTo.ClientID, hdnDropdowns.ClientID) btnFrom.Attributes("onclick") = String.Format(movejs, lstTo.ClientID, lstFrom.ClientID, hdnDropdowns.ClientID) Else If Not String.IsNullOrEmpty(hdnDropdowns.Value) Then PopulateListBoxes() End If End If End Sub End Class
<?php require_once("controls.php"); require_once("listbox.php"); class listpicker extends controls { var $lstFrom; var $lstTo; var $deserializable; function listpicker($id) { $this->attributes['id'] = $id; $this->lstFrom = new listbox($id.'_lstFrom'); $this->lstFrom->attributes['style'] = 'width:200px'; $this->lstFrom->attributes['onclick'] = "unselect('".$id."_lstTo')"; $this->lstTo = new listbox($id.'_lstTo'); $this->lstTo->attributes['style'] = 'width:200px'; $this->lstTo->attributes['onclick'] = "unselect('".$id."_lstFrom')"; if ($_REQUEST[$id.'$hdnDropdowns']) { $this->deserializable = true; $this->xml(urldecode($_REQUEST[$id.'$hdnDropdowns'])); } } function render() { $id = $this->attributes['id']; $html='<table> <tr> <td>' .$this->lstFrom->render(). '</td> <td> <input id="btnTo" type="button" value=">>" onclick="move(\''.$id.'_lstFrom\',\''.$id.'_lstTo\',\''.$id.'_hdnDropdowns\')" /> <br /> <input id="btnFrom" type="button" value="<<" onclick="move(\''.$id.'_lstTo\',\''.$id.'_lstFrom\',\''.$id.'_hdnDropdowns\')" /> </td> <td>' .$this->lstTo->render(). '</td> </tr> </table> <input type="hidden" ID="'.$id.'_hdnDropdowns" name="'.$id.'$hdnDropdowns" />'; return $html; } function xml($text) { $id = $this->attributes['id']; $parser = xml_parser_create(); xml_parse_into_struct($parser, $text, $vals); xml_parser_free($parser); $tag = ""; for($i = 0; $i < count($vals); $i++) { switch($vals[$i]['tag']) { case strtoupper($id.'_lstFrom') : $tag = "lstFrom"; break; case strtoupper($id.'_lstTo') : $tag = "lstTo"; break; } if (($tag) && ($vals[$i]['tag'] == "KEY")) { $this->{$tag}->addItem($vals[$i]['value'], $vals[$i+1]['value']); } } } } ?>
10+ items? May 7, 2010 by Kris
and I am using php and have actually 150 records to show!