7.12. Adding Data Types¶

junifer supports most of the data types required for fMRI but also provides a way to add custom data types in case you work with other modalities like EEG.

7.12.1. How to add a data type¶

Check extending junifer on how to create a junifer extension if you have not done so.
Define the data type schema in the extension script like so:
```
from junifer.datagrabber import DataTypeSchema


dtype_schema: DataTypeSchema = {
    "mandatory": ["pattern"],
    "optional": {
        "mask": {
            "mandatory": ["pattern"],
            "optional": [],
        },
    },
}
```
- The DataTypeSchema has two mandatory keys:
  - mandatory : list of str
  - optional : dict of str and OptionalTypeSchema
- mandatory defines the keys that must be present when defining a pattern in a DataGrabber.
- optional defines the mapping from sub-types that are optional, to their patterns. The patterns in turn require a mandatory key and an optional key both just being the keys that must be there if the optional key is found. It’s possible that the sub-type (mask in the example) can be absent from the dataset.

from junifer.datagrabber import register_data_type
...


# registers the data type as "dtype"
register_data_type(name="dtype", schema=dtype_schema)

...