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Hello

Im trying to retrieve a meta-data on scenes using the next request:


bbox=BBox('-53.44174990020377,-22.38538161005017,-53.43715803852127,-22.38024062362553', CRS.WGS84)

time_interval=('2021-02-01', '2021-03-01')

evalscript = """ //VERSION=3

function evaluatePixel() {}

function setup() {

    return {

        input: [{ bands:["dataMask", "CLM"]}],

        output: { bands: 0 },  

        mosaicking: "ORBIT",

    }

}

let col;

function preProcessScenes(collections){

    col = collections;

    return collections;

}

function updateOutputMetadata(scenes, inputMetadata, outputMetadata) {

    outputMetadata.userData = { 

        "scenes":scenes,

        "collections":col

    }

}"""



SentinelHubRequest(

    evalscript=evalscript,

    input_data=[

        SentinelHubRequest.input_data(data_collection=DataCollection.SENTINEL2_L1C, time_interval=time_interval)

    ],

    responses=[SentinelHubRequest.output_response('userdata', MimeType.JSON)],

    bbox=bbox,

    geometry=geometry,

    size = bbox_to_dimensions(bbox, resolution=60),

    config=config,

    data_folder='./data'

)

And here is what I’m receiving:


e{

'collections': {

    'scenes': :

        {'date': {}, '__idx': 0},

        {'date': {}, '__idx': 1},

        {'date': {}, '__idx': 2},

        {'date': {}, '__idx': 3},

        {'date': {}, '__idx': 4},

        {'date': {}, '__idx': 5}],

       'from': {},

       'to': {}

},

'scenes': :

       {'date': {}, 'bandBuffers': 🙂, '__idx': 0},

       {'date': {}, 'bandBuffers': 🙂, '__idx': 1},

       {'date': {}, 'bandBuffers': 🙂, '__idx': 2},

       {'date': {}, 'bandBuffers': 🙂, '__idx': 3},

       {'date': {}, 'bandBuffers': 🙂, '__idx': 4},

       {'date': {}, 'bandBuffers': 🙂, '__idx': 5}

]

}]

The “scenes” are missing the dates in both - preProcessScenes and updateOutputMetadata functions…

The question is - why are all of the dates missing?

I think that you are getting blank responses because the scenes and col variables are javascript objects. I converted the objects to strings in your example and got a response:

function updateOutputMetadata(scenes, inputMetadata, outputMetadata) {
    outputMetadata.userData = { 
        "scenes":JSON.stringify(scenes),
        "collections":JSON.stringify(col)
    }

can you confirm?

Yes, JavaScript Objects should be stringified.

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