sitecore programmatically change imagefield datasource - sitecore

Question

I need image field source of a product item to change depending on the folder path I am creating a product item under when creating the item in content or page editor.
If I am creating a product under /home/bicycles, I need the product item image field to auto change to /sitecore/media library/Images/bicycles
If I am creating a product under /home/cars, I need the product item image field to auto change to /sitecore/media library/Images/cars
If I am creating a product under /home/scooters, I need the product item image field to auto change to /sitecore/media library/Images/scooters
The default setting for that image field source in the datatemplate is /sitecore/media library/Images/bicycles
How can I go about doing this?

Answer 1

One option is to create a custom Content Editor field that extends the default image field type.
Start by creating a class that inherits from Sitecore.Shell.Applications.ContentEditor.Image. Then override the OnPreRender method to determine and set the Source property of the image field based on your location criteria/requirements.
See comments in the code below for more information.
public class ContextAwareImageField : Sitecore.Shell.Applications.ContentEditor.Image
{
/// <summary>
/// The ItemID proprety is set by the Content Editor via reflection
/// </summary>
public string ItemID { get; set; }
/// <summary>
/// Override the OnPreRender method.
/// The base OnPreRender method assigns a value to the Source viewstate property and we need to overwrite it.
/// </summary>
/// <param name="e"></param>
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
Source = GetSource();
}
protected virtual string GetSource()
{
//retrieve and return the computed source value if it has already been set
var contextSource = GetViewStateString("ContextSource");
if (!string.IsNullOrWhiteSpace(contextSource))
return contextSource;
//retrieve the context item (the item containing the image field)
var contextItem = Sitecore.Context.ContentDatabase.GetItem(ItemID);
if (contextItem == null)
return string.Empty;
//determine the source to be used by the media browser
//in this case we're just checking based on parent path, but any logic could be inserted
contextSource = "/sitecore/media library/Images";
switch (contextItem.Parent.Paths.FullPath.ToLowerInvariant())
{
case "/sitecore/content/home/bicycles":
contextSource = "/sitecore/media library/Images/Bicycles";
break;
case "/sitecore/content/home/cars":
contextSource = "/sitecore/media library/Images/Cars";
break;
case "/sitecore/content/home/scooters":
contextSource = "/sitecore/media library/Images/Scooters";
break;
}
//store the computed source value in view bag for later retrieval
SetViewStateString("ContextSource", contextSource);
//return the computed source value
return contextSource;
}
}
Next, perform the following steps:
Login to the Sitecore desktop with administrator rights and use the database icon in the lower right to switch to the Core database.
In the Core database, open the Content Editor then navigate to /sitecore/system/Field Types/Simple Types. There you will find an item representing the Image field type.
Duplicate the Image field type item and rename the duplicated item to something relevant (e.g. Context Aware Image).
Edit the duplicated item
In the Assembly field, provide the name of the assembly file containing your custom image field class (e.g. MyClient.MySite.dll)
In the Class field, provide the name of the custom image field class, including the namespace (e.g. MyClient.MySite.CustomFields.ContextAwareImageField)
Delete the value in the Control field
Save your changes
Switch back to the Master database.
Open the Content Editor, then navigate to a template that should contain your new image field.
Either create a new field in the template and choose your new custom field type in the Type dropdown. Or, change the Type for an existing image field.
Save your template changes.
In the content tree, navigate to an item based on the template above and click the Browse button for the contained image field. The media browser dialog should default to the source location specified by the logic in your custom field.
Note: if you are using a version of Sitecore that contains a SPEAK-based media browser dialog, you will have to switch to Tree View in the dialog (icon in the upper right) in order to see the source location specified by your custom field.