Link Browser doesn't show all child items from Tree?

Question

We're using Sitecore 8.1 Update 2 and have an issue where there is an instance where we have are a few hundred items under a single Parent item in our site. These child items show fine in the Content Editor Treeview, if a little slow to load them. I know best practice is to limit this to 100-200 items, it is however usable without converting the parent item to a Bucket. Re-architecting the structure at this stage isn't really an option.

However when using the Link Browser it shows the parent item but won't let me browse the child items. I get this error:

ERROR: No data from server

Update - here is a screenshot showing the parent item high-lighted with a red circle and the children failing to load.

Is there a hard limit on the number of items that the Link Browser support?

Eventually I want to convert these to a bucket but I'm looking for an interim solution in the short term.

Answer 1

I figured this out.

I made the update to change the value of LinkDatabase.MaximumBatchSize to 1000 as suggested and it didn't work.

<sitecore>
    <settings>
        <setting name="LinkDatabase.MaximumBatchSize">
            <patch:attribute name="value">1000</patch:attribute>
        </setting>
    </settings>
</sitecore>

I then looked at the console in more detail in Chrome and saw this error:

"Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property."

After some Googling I found I can update this via the web.config like so:

<system.web.extensions xdt:Transform="Insert">
        <scripting>
            <webServices>
                <jsonSerialization maxJsonLength="2147483647"/>
            </webServices>
        </scripting>
</system.web.extensions>

Again this didn't work :-(. I think the Json Serialization code ignores this setting.

Then I came across this Blog Post by Dirk Schäfauer: https://seitenkern.com/2014/03/28/sitecore-7-mvc-json-serialization-and-maxjsonlength/

This post says I need A custom JsonSerializer, a PreprocessRequest Pipeline and .config to patch in my pipeline. This code is outdated for 8.1 though so I've updated it below:

JsonSerializer:

namespace SitecoreContrib.Serialization
 {
      public class LargeJsonSerializer : ISerializer
    {
        public string SerializedDataMediaType
        {
            get { return "application/json"; }
        }

        public string Serialize(object value)
        {
            Assert.ArgumentNotNull(value, "value");
            var scriptSerializer = new JavaScriptSerializer { MaxJsonLength = 2097152 };
            var setting = Settings.GetSetting("JsonSerialization.MaxLength");
            int result;
            if (!string.IsNullOrEmpty(setting) && !scriptSerializer.MaxJsonLength.ToString(CultureInfo.InvariantCulture).Equals(setting, StringComparison.InvariantCultureIgnoreCase) && int.TryParse(setting, out result))
            {
                scriptSerializer.MaxJsonLength = result;
            }
            return scriptSerializer.Serialize(value);
        }
    }
  }

Pipeline:

namespace SitecoreContrib.Serialization.Pipelines.PreprocessRequest
{
      public class RewriteUrlForLargeJsonResponse : RewriteUrl
    {
        public override void Process(PreprocessRequestArgs arguments)
        {
            Assert.ArgumentNotNull((object)arguments, "arguments");
            try
            {
                string localPath = arguments.Context.Request.Url.LocalPath;
                if (!localPath.StartsWith("/-/item/"))
                    return;
                Sc.ItemWebApi.Context.Current = new Sc.ItemWebApi.Context
                {
                    Serializer = (ISerializer)new LargeJsonSerializer(),
                    Version = GetVersion(localPath),
                    ResponseOutputBuilder = new ResponseOutputBuilder()
                };
                Rewrite(arguments.Context);
            }
            catch (Exception ex)
            {
                Logger.Error(ex);
            }
        }

        private static int GetVersion(string path)
        {
            Assert.ArgumentNotNull((object)path, "path");
            string str = path.TrimStart('/').Split('/')[2];
            Assert.IsTrue(str.StartsWith("v"), "Version token is wrong.");
            int result;
            Assert.IsTrue(int.TryParse(str.Replace("v", string.Empty), out result), "Version not recognized.");
            return result;
        }

        private static void Rewrite(HttpContext context)
        {
            Assert.ArgumentNotNull((object)context, "context");
            Uri url = context.Request.Url;
            string[] strArray1 = url.LocalPath.TrimStart('/').Split('/');
            int length = strArray1.Length - 3;
            string[] strArray2 = new string[length];
            Array.Copy((Array)strArray1, 3, (Array)strArray2, 0, length);
            string str1 = string.Format("/{0}", (object)string.Join("/", strArray2));
            string str2 = url.Query.TrimStart('?');
            WebUtil.RewriteUrl(new UrlString
            {
                Path = str1,
                Query = str2
            }.ToString());
        }
    }
 }

Config:

<sitecore>
    <pipelines>
      <preprocessRequest>
        <processor type="SitecoreContrib.Serialization.Pipelines.PreprocessRequest.RewriteUrlForLargeJsonResponse, SitecoreContrib.Serialization" patch:instead="*[@type='Sitecore.ItemWebApi.Pipelines.PreprocessRequest.RewriteUrl, Sitecore.ItemWebApi']" />
      </preprocessRequest>
    </pipelines>
    <settings>
      <!-- JsonSerialization.MaxLength
           Specifies the maximum length of JSON strings which can be serialized by the JsonSerializer.
           Value is specified in bytes. Default value: 2097152 (2 MB)
      -->
      <setting name="JsonSerialization.MaxLength" value="2147483647" />
    </settings>
  </sitecore>

Thats it, this should work well and load large json datasets for you when you have lots of sub-items.