FR: add_stac_layer to accept a pystac.item.Item directly

[robmarkcole]

Description

The API I am working with doesn't return a stac json file on a url, and I understand this is not a firm requirement.

This FR is to support passing apystac.item.Item directly to add_stac_layer

Source code

assert type(item) == pystac.item.Item

m = leafmap.Map()
m.add_stac_layer(item, bands=["red", "green", "blue"], name="False color")
m

Current workaround

Dump item to local file, run a local server, point to url

item_file = "item.json"
with open(item_url, 'w') as f:
  json.dump(item.to_dict(), f)

os.system(f"python -m http.server 8080 &") # Serving HTTP on 0.0.0.0 port 8080 (http://0.0.0.0:8080/) ...
item_url = "http://0.0.0.0:8080/" + item_file

m = leafmap.Map()
m.add_stac_layer(item_url, bands=["red", "green", "blue"], name="False color")
m

[giswqs]

Would this work for you?

assert type(item) == pystac.item.Item
url = item.self_href

m = leafmap.Map()
m.add_stac_layer(url, assets=["red", "green", "blue"], name="False color")
m

[robmarkcole]

In my case that returns Client error '401 Unauthorized' for url - not sure if that is specific to our api, but we are using presigned urls for the tifs themselves

[giswqs]

It may be your own api problem. A standard pystac Item should have the self_href attribute for retrieving the URL. Try the following example.

import leafmap

url = "https://earth-search.aws.element84.com/v1/"
collection = "sentinel-2-l2a"
time_range = "2020-12-01/2020-12-31"
bbox = [-122.2751, 47.5469, -121.9613, 47.7458]
result = leafmap.stac_search(
    url=url,
    max_items=10,
    collections=[collection],
    bbox=bbox,
    datetime=time_range,
    query={"eo:cloud_cover": {"lt": 10}},
    sortby=[{"field": "properties.eo:cloud_cover", "direction": "asc"}],
)
item = result.get_all_items()[-1]
m = leafmap.Map()
m.add_stac_layer(item.self_href, assets=["nir", "red", "green"])
m

[robmarkcole]

Thanks - I believe the issue is that url is not a pre signed url currently, so auth fails

[giswqs]

Should we close this issue? Or is there anything leafmap should improve to support this?

[robmarkcole]

I still think it would be great to support pystac.item.Item as an arg, but if that is not going to happen we can close

[giswqs]

pystac.Item support has been added in #944

[robmarkcole]

Amazing speed on this, thanks!

[giswqs]

My pleasure! Thank you for the suggestion.