Using Strongly Typed Custom Document Type Classes in Kentico CMS
Kentico is a great platform for building web apps, but some times the API code doesn’t feel like it’s as good as it could be:
TreeNode document = treeProvider.Select(...);
var integerValue = ValidationHelper.GetInteger(document.GetValue("Age"), 0);
Sure, that works reliably, but using ValidationHelper everywhere along with the string names of the fields isn’t conducive to good programming habits. Why don’t we fix that using a strongly typed class for our custom Document Type. Just grab the boilerplate code from C:\Program Files (x86)\KenticoCMS\7.0\CodeSamples\App_Code Samples\Samples\Classes, and create property’s for each of the Document Type fields.
Let’s say I had a Person Document Type with:
- First Name
- Last Name
- Age
The end result of the custom Document Type class looks like this:
using System;
using CMS.DocumentEngine;
/// <summary>
/// Document type registration
/// </summary>
[DocumentType(PersonDocument.CLASS_NAME, typeof(PersonDocument))]
public partial class CMSModuleLoader
{
}
/// <summary>
/// Person document type class, deriving from TreeNode
/// </summary>
public partial class PersonDocument : TreeNode
{
/// <summary>
/// Class name of the item
/// </summary>
public const string CLASS_NAME = "Custom.Person";
public string FirstName
{
get
{
return GetStringValue("FirstName", "");
}
set
{
SetValue("FirstName", value);
}
}
public string LastName
{
get
{
return GetStringValue("LastName", "");
}
set
{
SetValue("LastName", value);
}
}
public int Age
{
get
{
return GetIntegerValue("Age", 0);
}
set
{
SetValue("Age", value);
}
}
public PersonDocument()
: base(CLASS_NAME)
{
}
}
And the following is an example of using the Kentico API to retrieve a list of Person documents from the content tree. We select only “Person” documents, and are able to use our custom class to deal with the data in a strongly-typed fashion:
var treeProvider = new TreeProvider();
var documents = treeProvider.SelectNodes(CMSContext.CurrentSiteName, "/%", "en-us", false, "custom.Person");
if (!DataHelper.DataSourceIsEmpty(documents))
{
// Loop through all documents
foreach (PersonDocument person in documents.Items)
{
// Alternatively, if you're dealing with a DataSet you can new up a person from the DataRow
// var person = TreeNode.New<PersonDocument>(documentRow, "custom.Person", treeProvider);
Response.Write(string.Format("{0} {1}", person.FirstName, person.LastName));
}
}
The only caveat here is that your custom Document Type needs to match the class you created, otherwise things will break. But that is definitely a risk that is easily mitigated with permissions and educated developers. And if things do need to change, which inevitably they will, Visual Studio and/or ReSharper will help you refactor things with minimal effort.
But wait, there’s more!
If you didn’t get nosy already, check out the other files in the samples folder in Kentico’s install directory: C:\Program Files (x86)\KenticoCMS\7.0\CodeSamples\App_Code Samples\Samples\Classes. Notice how they have samples for Custom Table Items and Bizform Items! They essentially follow the same pattern, but with their respective provider classes. Strongly typed code for everyone!