Settings for your application or module

The other day I held a presentation of the Epicode Netmeeting module at the EPiServer Meetup. Settings for this module is stored in its own config section i Web.Config. Stein Viggo asked me if there is another way for storing config settings. And indeed there is. Here is a solution for doing so.

I have a module for showing scaled and cropped pictures. This module has two settings in its own config section:

<ImageResizerSettings>
    <add key="AllowedPictureFormats" value="jpg,jpeg,png,gif,tif,tiff" />
    <add key="ScaledImagesProviderName" value="ScaledImages" />        
</ImageResizerSettings>

I want to store these settings in the dll for this module. Make a class that uses the GuiPlugIn attribute.

using System;
using System.Web.UI.WebControls;
using EPiServer.PlugIn;

namespace Epinova.ImageResizer.Utilities
{
    [GuiPlugIn(Area = PlugInArea.None, DisplayName = "ImageResizerSettings")]
    public class ImageResizerSettings
    {
        private static ImageResizerSettings _instance;

        [PlugInProperty(Description = "Allowed picture formats", AdminControl = typeof(TextBox), AdminControlValue = "Text")]
        public string AllowedPictureFormats { get; set; }

        [PlugInProperty(Description = "The name of the provider where the scaled images are stored", AdminControl = typeof(TextBox), AdminControlValue = "Text")]
        public string ScaledImagesProviderName { get; set; }

        public ImageResizerSettings()
        {
            PlugInSettings.SettingsChanged += new EventHandler(PlugInSettings_SettingsChanged);
        }

        private static void PlugInSettings_SettingsChanged(object sender, EventArgs e)
        {
            _instance = null;
        }

        public static ImageResizerSettings Instance
        {
            get
            {
                if (_instance == null)
                {
                    _instance = new ImageResizerSettings();
                }
                PlugInSettings.AutoPopulate(_instance);
                return _instance;
            }
        }
    }
}

Build your solution and go to admin mode and select the "Config tab". Then click the "Plug-in Manager"

Select the name of your dll and your configuration settings will appear. Fill in the settings and click "Save".

Now you can access these settings in code like this:

string filesystemProviderName = ImageResizerSettings.Instance.ScaledImagesProviderName;

private readonly string _allowedExtenstions = ImageResizerSettings.Instance.AllowedPictureFormats;

A common way to store settings is to a PageReference. You can do it in the following way:

[PlugInProperty(Description = "Link to a page", AdminControl = typeof(InputPageReference), AdminControlValue = "PageLink")]
public PageReference LinkToPage{ get; set; }

The PageReference is accessed the same way as the other settings:

ImageResizerSettings.Instance.LinkToPage.

If you want to add a reference to a PageTypeId, you can use this class:

using System;
using System.ComponentModel;
using System.Web.UI;
using System.Web.UI.WebControls;
using EPiServer.DataAbstraction;
using EPiServer.Web.WebControls;

namespace YourNameSpace{
[Serializable, DefaultProperty("PageTypeID"), ToolboxItem(false), ValidationProperty("PageTypeID"), ToolboxData("<{0}:InputPageType runat=server></{0}:InputPageType>")]
    public class InputPageType : InputBase
    {
        DropDownList _ddl = new DropDownList() { DataSource = PageType.List(), DataTextField = "LocalizedName", DataValueField = "ID" };

        public int PageTypeID
        {
            get { int val; int.TryParse(_ddl.SelectedValue, out val); return val; }
            set { _ddl.SelectedValue = value.ToString(); }
        }

        protected override void CreateChildControls()
        {
            _ddl.DataBind();
            Controls.Add(_ddl);
        }
    }
}

The PageTypeId can be references like this in you Settings class:

[PlugInProperty(Description = "Your PageType", AdminControl = typeof(InputPageType), AdminControlValue = "PageTypeID")]
 public int YourPageTypeId{ get; set; }

And you can use it in your code like this:

ImageResizerSettings.Instance.YourPageTypeId

So what do you think, is a good way to store your settings?

Thanks to Thomas Leela for showing me this nice solution!