How to remove 'route' object in Sitecore jss layout service api response?

Question

When I get the data from http://{domain.name}/sitecore/api/layout/render/jss?item=/&sc_apikey=[api-key]

Then response is like {sitecore: {context:{something}, route:{something}}

But I don't want to include the route object if, in my custom layout service extension code some condition is not met.

Answer 1

The most straightforward approach will likely be to extend and customize the Sitecore.JavaScriptServices.ViewEngine.LayoutService.Serialization.LayoutTransformer, specifically, the Transform(RenderedItem rendered) method.

The default LayoutTransformer is declared via config in /App_Config/Sitecore/LayoutService/Sitecore.LayoutService.Jss.config.

You'll see the jss named configuration for Layout Service:

<config name="jss">
  <rendering type="Sitecore.LayoutService.Configuration.DefaultRenderingConfiguration, Sitecore.LayoutService">
    <placeholdersResolver type="Sitecore.LayoutService.Placeholders.DynamicPlaceholdersResolver, Sitecore.LayoutService" />
    <itemSerializer type="Sitecore.JavaScriptServices.ViewEngine.LayoutService.JssItemSerializer, Sitecore.JavaScriptServices.ViewEngine" resolve="true">
      <AlwaysIncludeEmptyFields>true</AlwaysIncludeEmptyFields>
    </itemSerializer>
    <renderingContentsResolver type="Sitecore.LayoutService.ItemRendering.ContentsResolvers.RenderingContentsResolver, Sitecore.LayoutService">
      <IncludeServerUrlInMediaUrls>true</IncludeServerUrlInMediaUrls>
    </renderingContentsResolver>
  </rendering>
  <serialization type="Sitecore.JavaScriptServices.ViewEngine.LayoutService.SerializationConfiguration, Sitecore.JavaScriptServices.ViewEngine">
    <transformer type="Sitecore.JavaScriptServices.ViewEngine.LayoutService.Serialization.LayoutTransformer, Sitecore.JavaScriptServices.ViewEngine" resolve="true" />
  </serialization>
</config>

And within that named configuration is the LayoutTransformer declaration (config/rendering/serialization/transformer).

Lastly, a custom layout transformer may look something like below. Note that if the custom condition is met, then the route object will not be in the final output.

public class CustomLayoutTransformer : LayoutTransformer    
{
    public CustomLayoutTransformer(IPlaceholderTransformer placeholderTransformer) : base(placeholderTransformer)
    {
    }

    public override dynamic Transform(RenderedItem rendered)
    {
        var baseResult = base.Transform(rendered);

        if (myCustomCondition)
        {
            dynamic newResult = new ExpandoObject();
            newResult.sitecore = new
            {
                baseResult.context
            };
            return newResult;
        }

        return baseResult;
    }
}