Request `_items` only using python-eve API to a MongoDB

I am using an python-eve-API (short called eve) to access a MongoDB. After inserting some sample data I am using Chrome's Postman to test the API.

Since eve provides additional information besides the requested data and HATEOAS directives as explained in the docs I just wondered about how to request the _items-dictionary only (call it dictionary if speaking in terms of Python and object if speaking in terms of JSON or JavaScript).

So the sample request http://127.0.0.1:5000/packagings/ gives the response shown below from which I am only interested in the data contained in the _items-dictionary/-object.

For sure, I can extract the desired data after receiving and storing the full response. However, is there a way to only request the data I am interested in in order to reduce additional data extraction resp. data handling once the data are received?

{
    "_links": {
        "self": {
            "href": "packagings",
            "title": "packagings"
        },
        "parent": {
            "href": "/",
            "title": "home"
        }
    },
    "_meta": {
        "max_results": 25,
        "page": 1,
        "total": 1
    },
    "_items": [
        {
            "diameter_dk": 0.0144,
            "_created": "Tue, 17 Nov 2015 21:15:37 GMT",
            "factor_fa": 2.1,
            "_id": "564b98f955c40f29843128df",
            "free_volume": 0.89,
            "title": "raschigring10x10x0.5",
            "_updated": "Tue, 17 Nov 2015 21:15:37 GMT",
            "_links": {
                "self": {
                    "href": "packagings/564b98f955c40f29843128df",
                    "title": "Packaging"
                }
            },
            "specific_weight": 920,
            "title_hr": "Raschig-Ring 10x10x0.5",
            "specific_surface": 500,
            "specific_number": 770000,
            "_etag": "bcb4080b61028405babcd960196d27208c3eabd3"
        }
    ]
}

Solution

You can disable HATEOAS by setting HATEOAS = False in your configuration settings. That should greatly reduce the payload, making it more suitable for your use case.

EDIT: You can also choose to transform the response payload by hooking a callback function to the on_fetched_resource event.

from eve import Eve

def on_fetched_resource(resource, response):
    del(response['_links'])
    del(response['_meta'])

    # would result in an empty JSON document
    # del(response['_items'])

app = Eve()
app.on_fetched_resource += on_fetched_resource

if __name__ == '__main__':
    app.run()

Since the response is a dict (it's JSON after all), you would still need to provide a key for the documents array.