How to Create Custom MultiColumn Field Types in SharePoint 2010

Introduction

This article explains how to create Multicolumn Custom Field Types in SharePoint. Suppose we have a scenario like in our list there is a column Address that has the fields Country, State, City, ZipCode, Street Address and so on. So one solution is to create multiple fields in a SharePoint list for each field or we can create a custom multicolumn field that handles all fields as a single logical unit.

How

Now suppose our custom field name is MyAddressField that has the following fields:

Street Address Line
City
State
Country
Zip Code

The following are the steps that are required to create a Multicolumn Custom Field Type:

Create an Empty SharePoint Project as a Farm solution named as MyAddressField
In the solution add a SharePoint Mapped Folder of Template-Control Template
Now click on this Control Template Folder and add a user control named MyAddressRenderingTemplate.ascx
Add following code to the ascx file:

<SharePoint:RenderingTemplaterunat="server"ID="MyAddressRenderingTemplate">

<Template>

<table>

<tr>

<td>Address Street:</td>

<td><asp:TextBoxID="txtAddress"runat="server"/></td>

</tr>

<tr>

<td>City:</td>

<td><asp:TextBoxID="txtCity"runat="server"/></td>

</tr>

<tr>

<td>State:</td>

<td><asp:TextBoxID="txtState"runat="server"/></td>

</tr>

<tr>

<td>Country:</td>

<td><asp:TextBoxID="txtCountry" runat="server"/></td>

</tr>

<tr>

<td>Zipcode:</td>

<td><asp:TextBoxID="txtZipcode"runat="server"/></td>

</tr>

</table>

</Template>
</SharePoint:RenderingTemplate>
Add a class named MyAddress.cs and write the following code:

publicclass MyAddress : SPFieldMultiColumn

{

public MyAddress(SPFieldCollection fields,

string fieldName)

:base(fields, fieldName) { }

public MyAddress(SPFieldCollection fields,

string typeName,

string displayName)

:base(fields, typeName, displayName) { }

public overrideBaseFieldControl FieldRenderingControl

{

get

{

BaseFieldControl ctr =new MyAddressFieldControl();

ctr.FieldName = this.InternalName;

return ctr;

}

}

public overridestring GetFieldValueAsHtml(object value)

{

string HtmlLineBreak =@"<br />";

SPFieldMultiColumnValue mColumnValue =

new SPFieldMultiColumnValue(value.ToString());

string HtmlAddress = mColumnValue [0].ToString() + HtmlLineBreak;

if (!string.IsNullOrEmpty(mcv[1]))

{

HtmlAddress += mcv[1].ToString() + HtmlLineBreak;

}

HtmlAddress += mColumnValue [2].ToString() + ", " + mColumnValue [3] + " " + mColumnValue [4];

return HtmlAddress;

}

}

publicclass MyAddressFieldControl : BaseFieldControl

{

protected overridestring DefaultTemplateName

{

get { return"MyAddressRenderingTemplate"; }

}

protected TextBox txtAddress;

protected TextBox txtCity;

protected TextBox txtState;

protected TextBox txtCountry;

protected TextBox txtZipcode;

protected overridevoid CreateChildControls()

{

base.CreateChildControls();

txtAddress =

(TextBox)this.TemplateContainer.FindControl("txtAddress");

txtCity =

(TextBox)this.TemplateContainer.FindControl("txtCity");

txtState =

(TextBox)this.TemplateContainer.FindControl("txtState");

txtCountry =

(TextBox)this.TemplateContainer.FindControl("txtCountry");

txtZipcode =

(TextBox)this.TemplateContainer.FindControl("txtZipcode");

}

public overrideobject Value

{

get

{

this.EnsureChildControls();

SPFieldMultiColumnValue mColumnValue =new SPFieldMultiColumnValue(5);

mColumnValue [0] = txtAddress.Text;

mColumnValue [1] = txtCity.Text.ToUpper();

mColumnValue [2] = txtState.Text;

mColumnValue [3] = txtCountry.Text;

mColumnValue [4] = txtZipcode.Text;

return mColumnValue;

}

set

{

this.EnsureChildControls();

SPFieldMultiColumnValue mColumnValue =

(SPFieldMultiColumnValue)this.ItemFieldValue;

txtAddress.Text = mColumnValue [0];

txtCity.Text = mColumnValue [1];

txtState.Text = mColumnValue [2];

txtCountry.Text = mColumnValue [3];

txtZipcode.Text = mColumnValue [4];

}

}
}
Add another SharePoint Mapped Folder. Right-click on the solution, click on the "Add" menu and now click on "SharePoint Mapped Folder". You need to choose the Template-->XML folder. Now it will add a folder named XML to your solution.
Right-click on this XML folder and add an XML file named fldtypes_MyAddressFields.xml

Add the following code inside this file.

<FieldTypes>
<FieldType>
<FieldName="TypeName">MYAddress</Field>
<FieldName="ParentType">MultiColumn</Field>
<FieldName="TypeDisplayName">MY Address</Field>
<FieldName="TypeShortDescription">My Address</Field>
<FieldName="UserCreatable">TRUE</Field>
<FieldName="ShowInListCreate">TRUE</Field>
<FieldName="FieldTypeClass">
MyAddressField.MyAddress,$SharePoint.Project.AssemblyFullName$
</Field>
</FieldType>
</FieldTypes>

Finally the Project Structure will look like this:

Now deploy the solution and in your SharePoint site try to add a new column. You will then see there is a custom field named "MyAddressField". Add this column, you can find the multicolumn field when you try to insert a new record into your list.