On a recent project, I found the need to set field data on new media library items using the Sitecore Item Web API — a feature that is not supported “out of the box”.
After digging through Sitecore.ItemWebApi.dll, I discovered where one could add the ability to update fields on newly created media library items:
Unfortunately, the CreateMediaItems method in the Sitecore.ItemWebApi.Pipelines.Request.ResolveAction class is declared private — introducing code to set fields on new media library items will require some copying and pasting of code.
Honestly, I loathe duplicating code. 
Unfortunately, we must do it in order to add the capability of setting fields on media library items via the Sitecore Item Web API (if you can think of a better way, please leave a comment).
I did just that on the following subclass of Sitecore.ItemWebApi.Pipelines.Request.ResolveAction:
using System;
using System.Collections.Generic;
using System.IO;
using System.Web;
using Sitecore.Data;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.IO;
using Sitecore.ItemWebApi;
using Sitecore.ItemWebApi.Pipelines.Read;
using Sitecore.ItemWebApi.Pipelines.Request;
using Sitecore.Pipelines;
using Sitecore.Resources.Media;
using Sitecore.Text;
using Sitecore.Data.Fields;
namespace Sitecore.Sandbox.ItemWebApi.Pipelines.Request
{
public class ResolveActionMediaItems : ResolveAction
{
protected override void ExecuteCreateRequest(RequestArgs args)
{
Assert.ArgumentNotNull(args, "args");
if (IsMediaCreation(args.Context))
{
CreateMediaItems(args);
return;
}
base.ExecuteCreateRequest(args);
}
private void CreateMediaItems(RequestArgs args)
{
Assert.ArgumentNotNull(args, "args");
Item parent = args.Context.Item;
if (parent == null)
{
throw new Exception("The specified location not found.");
}
string fullPath = parent.Paths.FullPath;
if (!fullPath.StartsWith("/sitecore/media library"))
{
throw new Exception(string.Format("The specified location of media items is not in the Media Library ({0}).", fullPath));
}
string name = args.Context.HttpContext.Request.Params["name"];
if (string.IsNullOrEmpty(name))
{
throw new Exception("Item name not specified (HTTP parameter 'name').");
}
Database database = args.Context.Database;
Assert.IsNotNull(database, "Database not resolved.");
HttpFileCollection files = args.Context.HttpContext.Request.Files;
Assert.IsTrue(files.Count > 0, "Files not found.");
List<Item> list = new List<Item>();
for (int i = 0; i < files.Count; i++)
{
HttpPostedFile file = files[i];
if (file.ContentLength != 0)
{
string fileName = file.FileName;
string uniqueName = ItemUtil.GetUniqueName(parent, name);
string destination = string.Format("{0}/{1}", fullPath, uniqueName);
MediaCreatorOptions options = new MediaCreatorOptions
{
AlternateText = fileName,
Database = database,
Destination = destination,
Versioned = false
};
Stream inputStream = file.InputStream;
string extension = FileUtil.GetExtension(fileName);
string filePath = string.Format("{0}.{1}", uniqueName, extension);
try
{
Item item = MediaManager.Creator.CreateFromStream(inputStream, filePath, options);
SetFields(item, args.Context.HttpContext.Request["fields"]); // MR: set field data on item if data is passed
list.Add(item);
}
catch
{
Logger.Warn("Cannot create the media item.");
}
}
}
ReadArgs readArgs = new ReadArgs(list.ToArray());
CorePipeline.Run("itemWebApiRead", readArgs);
args.Result = readArgs.Result;
}
private static void SetFields(Item item, string fieldsQueryString)
{
if (!string.IsNullOrWhiteSpace(fieldsQueryString))
{
SetFields(item, new UrlString(fieldsQueryString));
}
}
private static void SetFields(Item item, UrlString fields)
{
Assert.ArgumentNotNull(item, "item");
Assert.ArgumentNotNull(fields, "fields");
if (fields.Parameters.Count < 1)
{
return;
}
item.Editing.BeginEdit();
foreach (string fieldName in fields.Parameters.Keys)
{
Field field = item.Fields[fieldName];
if(field != null)
{
field.Value = fields.Parameters[fieldName];
}
}
item.Editing.EndEdit();
}
private bool IsMediaCreation(Sitecore.ItemWebApi.Context context)
{
Assert.ArgumentNotNull(context, "context");
return context.HttpContext.Request.Files.Count > 0;
}
}
}
The above class reads fields supplied by client code via a query string passed in a query string parameter — the fields query string must be “url encoded” by the client code before being passed in the outer query string.
We then delegate to an instance of the Sitecore.Text.UrlString class when fields are supplied by client code — if you don’t check to see if the query string is null, empty or whitespace, the UrlString class will throw an exception if it’s not set — to parse the fields query string, and loop over the parameters within it — each parameter represents a field to be set on the item, and is set if it exists (see the SetFields methods above).
I replaced Sitecore.ItemWebApi.Pipelines.Request.ResolveAction in \App_Config\Include\Sitecore.ItemWebApi.config with our new pipeline processor above:
<?xml version="1.0" encoding="utf-8"?> <configuration xmlns:patch="http://www.sitecore.net/xmlconfig/"> <sitecore> <pipelines> <!-- there is more stuff up here --> <!--Processes Item Web API requests. --> <itemWebApiRequest> <!-- there are more pipeline processors up here --> <processor type="Sitecore.Sandbox.ItemWebApi.Pipelines.Request.ResolveActionMediaItems, Sitecore.Sandbox" /> <!-- there are more pipeline processors down here --> </itemWebApiRequest> <!-- there is more stuff down here --> </pipelines> </sitecore> </configuration>
I then modified the media library item creation code in my copy of the console application written by Kern Herskind Nightingale — Director of Technical Services at Sitecore UK — to send field data to the Sitecore Item Web API:
I set some fields using test data:
After I ran the console application, I got a response — this is a good sign 
As you can see, our test field data has been set on our pizza media library item:
If you have any thoughts or suggestions on this, please drop a comment.
Now I’m hungry — perhaps I’ll order a pizza!
