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Object orientated programming within JavaScript 2010-01-28 07:25:45
How to sort data using ASP.net (C#) and SQL 2005/8 2010-01-18 15:23:14
Quick look at some of the new features added to C# 4.0 2010-01-12 21:52:13
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I need guinea pigs ;) 2009-08-04 22:26:04
Creating a WYSIWYG textbox for your website is actually quite simple. 2007-02-01 12:00:00
Move items between two listboxes in ASP.net(C#, VB.NET) and PHP 2008-06-12 17:07:43
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2007-02-22 12:00:00
Often you'll hear the term "strongly typed" which refers to certain constraints being enforced regarding variables 2007-01-28 12:00:00
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). You can download the full working source code here, contains sources for ASP.net(C# & VB.NET) and PHP source code. 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[' + dropdown.options[i].text + ']]></key><value><![CDATA[' + dropdown.options[i].value + ']]></value></option>'; } value+='</' + dropdown.id + '>'; return value } function unselect(listbox) { document.getElementById(listbox).selectedIndex=-1; } Tying it all together (javascript with some .net code), you can easily write yourself an usercontrol, like I did in my example, or create a composite control. The .net code below is pretty straighforward, you'll noticed two publicly exposed ListBox properties (lstFrom, lstTo), giving us easy access to the listboxes. If you really need to, you can easily add third, forth listboxes (with slight changes to the javascript code) The PHP code is quite a bit more involved, I had to create a few classes that give similiar control of what you would expect from an ASP.NET server side control. There is a lot easier ways to do this, but I believe this is a fairly manageable approach. C# 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(node["key"].InnerText, 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.TemplateSourceDirectory + "/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(); } } } } VB.net 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(node.Item("key").InnerText, 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.TemplateSourceDirectory & "/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 <?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']); } } } } ?>
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[' + dropdown.options[i].text + ']]></key><value><![CDATA[' + 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(node["key"].InnerText, 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.TemplateSourceDirectory + "/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(node.Item("key").InnerText, 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.TemplateSourceDirectory & "/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']); } } } } ?>
Yes Please! It would make a big difference to have other ways of using your code
Basically you'll need to iterate through your query results, adding items to the listbox via your iteration, do you need an example of how to do this?
thanks that worked. If you dont mind me asking how would i work a list box into this where the content comes from a database and not your list. So box 1 is "NewTownList" dynamically populated using sql SELECT Query "this works" just need to know how i would tie "NewTownList" into your code Thanks a mil
try replacing <?=$picker->render(); ?> with <?php echo $picker->render(); ?> on the index.php page
render(); ?>, this is all i see when i run the index.php
Thank you for the feedback. This is actually by design. I went on the assumption that if no xml are available it means the user didnt alter anything to the lists - hence no editing happend - in turn no update needed. But I can understand that it might be required to pass it either way in certain cases. (But generally one can simply return the original values from the db either way - if needed)
One thing I noticed that I had to do to get this working for me was that if the user does not touch the list you do not setup the xml. You only do this when they move an item. This is OK if it is a new form but if you are using this on say an edit feature it shows nothing once they submit the form under values. I just did a function that called your serialize function and did an onload call. This is under PHP BTW. Otherwise it is a great script!
The code was really helpful and I could skip writing this functionality. Thanks - Madhu G
Please help! Invalid Callback or post back error
Hi Ken Sorry I've only noticed your comment just now. You wont need to deserialize the xml content yourself, the class already takes care of it, you'll notice two properties, lstFrom and lstTo they contain the items (plus updated items from the post request already deserialized for you) If you post to another form, you simply need to instantiate the class on the page (with the same id) eg. $picker = new listpicker("picker"); And simply iterate through the items. eg foreach($picker->lstFrom as $key=>$value) { } foreach($picker->lstTo as $key=>$value) { } Let me know if you've got any questions?
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Codebooth my semi-community site etc (work in progress)
The company I'am currently working for as software developer.
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