Declaring the root folder

Estimated time: 3 minutes

Overview

Questions

• What is the root folder?

Objectives

• Create a top-level entity that can list the parts of the crate

RO-Crate Root

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First we’ll add an entity to the @graph array, to describe the RO-Crate Root:

JSON

{
    "@id": "./",
    "@type": "Dataset",
    "hasPart": [ 

    ]
}

By convention, in RO-Crate the @id value of ./ means that this entity describes the folder in which the RO-Crate metadata file is located. The root data entity always has the @type value of Dataset, which is a schema.org type. This will be referenced from ro-crate-metadata.json, semantically marking the crate1 folder as being the RO-Crate Root.

RO-Crates can be published on the Web

This example is a folder-based RO-Crate stored on disk, and therefore absolute paths are avoided, e.g. in case the root folder is moved or archived as a ZIP file.

If the crate is being served from a Web service, such as a data repository or database where files are not organized in folders, then the @id might be an absolute URI instead of ./ – this is one reason why we point to the root entity from the metadata descriptor, as you will see in the next section.

Add an additional type

1. Navigate the schema.org type list to find a subtype of CreativeWork that is suitable for a learning resource.
2. Modify the root entity’s @type to be an array.
3. Add the type name for learning resource at the end of the array.

Show me the solution

JSON

{
   "@id": "./",
   "@type": ["Dataset", "LearningResource"],
   "hasPart": [ 
     {"@id": "data.csv"} 
   ],
   "…": "…"
}

The root has several metadata properties that describe the RO-Crate as a whole, considering it as a Research Object of collected resources. In the next section we will cover the required and recommended properties of the root ./.

Key Points

• The RO-Crate Root is the top-level object of the RO-Crate
• The root identifier is commonly just ./ for the current folder, but can be a URL
• The root is always typed as a Dataset, but can have additional types