Sitecore JSS Limit depth of items retrieved in linked fields - sitecore

Question

I have an App Route A for a page and is loading all the fields including a multilist that links to Item App Route B that can have in the multilist a link to Item A, creating a infinite loop. Is there a way to set the depth to only one level?
AppRoute A:
fields:
multifield:
AppRoute B
AppRoute B:
fields:
multifield:
AppRoute A

Answer 1

There are two options, you can create a patch for the configuration file to update the layoutService serializationMaxDepth, but this will affect all the Items:
<configuration>
<sitecore>
<settings>
<layoutService>
<serializationMaxDepth>2</serializationMaxDepth>
</layoutService>
</sitecore>
</configuration>
Or you can craete your custom field serialization resolver.
This class will add the information to the field:
public class CustomFieldSerializer : BaseFieldSerializer
{
public CustomFieldSerializer (IFieldRenderer fieldRenderer)
: base(fieldRenderer)
{
}
protected override void WriteValue(Field field, JsonTextWriter writer)
{
writer.WriteStartObject();
writer.WritePropertyName(field.Name);
writer.WriteValue("Your custom field value here.");
writer.WriteEndObject();
}
}
This class will be the field resolver:
public class GetCustomFieldSerializer : BaseGetFieldSerializer
{
public GetCustomFieldSerializer(IFieldRenderer fieldRenderer)
: base(fieldRenderer)
{
}
protected override void SetResult(GetFieldSerializerPipelineArgs args)
{
Assert.ArgumentNotNull((object)args, nameof(args));
args.Result = new CustomFieldSerializer(this.FieldRenderer);
}
}
And this is the configuration patch to set the resolver class to your field. Make sure to place your config(patch:before) before the field default serialization configuration, in this case the multililist is GetMultilistFieldSerializer you can check this in https://<your-sitecore-domain>/sitecore/admin/showconfig.aspx:
<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
<sitecore>
<pipelines>
<group groupName="layoutService">
<pipelines>
<getFieldSerializer>
<processor patch:before="processor[#type='Sitecore.LayoutService.Serialization.Pipelines.GetFieldSerializer.GetMultilistFieldSerializer, Sitecore.LayoutService']" type="Foundation.FieldSerializer.GetCustomFieldSerializer, Foundation.LayoutService" resolve="true">
<FieldTypes hint="list">
<fieldType id="1">multilist</fieldType>
</FieldTypes>
</processor>
</getFieldSerializer>
</pipelines>
</group>
</pipelines>
</sitecore>
</configuration>