Better handling of HTTP header

rocrate/model/file.py

@@ -20,10 +20,10 @@
 # limitations under the License.
 
 from pathlib import Path
+import requests
 import shutil
 import urllib.request
 import warnings
-from http.client import HTTPResponse
 from io import BytesIO, StringIO
 
 from .file_or_dir import FileOrDir
@@ -48,19 +48,20 @@ def write(self, base_path):
                 out_file.write(self.source.getvalue())
         elif is_url(str(self.source)):
             if self.fetch_remote or self.validate_url:
-                with urllib.request.urlopen(self.source) as response:
-                    if self.validate_url:
-                        if isinstance(response, HTTPResponse):
+                if self.validate_url:
+                    if self.source.startswith("http"):
+                        with requests.head(self.source) as response:
                             self._jsonld.update({
-                                'contentSize': response.getheader('Content-Length'),
-                                'encodingFormat': response.getheader('Content-Type')
+                                'contentSize': response.headers.get('Content-Length'),
+                                'encodingFormat': response.headers.get('Content-Type')
                             })
                         if not self.fetch_remote:
-                            self._jsonld['sdDatePublished'] = iso_now()
-                    if self.fetch_remote:
-                        out_file_path.parent.mkdir(parents=True, exist_ok=True)
-                        urllib.request.urlretrieve(response.url, out_file_path)
-                        self._jsonld['contentUrl'] = str(self.source)
+                            date_published = response.headers.get("Last-Modified", iso_now())
+                            self._jsonld['sdDatePublished'] = date_published
+                if self.fetch_remote:
+                    out_file_path.parent.mkdir(parents=True, exist_ok=True)
+                    urllib.request.urlretrieve(self.source, out_file_path)
+                    self._jsonld['contentUrl'] = str(self.source)
         elif self.source is None:
             # Allows to record a File entity whose @id does not exist, see #73
             warnings.warn(f"No source for {self.id}")

test/test_write.py

@@ -19,6 +19,7 @@
 
 import io
 import pytest
+import requests
 import os
 import uuid
 import sys
@@ -435,3 +436,19 @@ def test_add_tree(test_data_dir, tmpdir):
 
     with pytest.raises(ValueError):
         crate.add_tree(None, dest_path="foobar")
+
+
+def test_http_header(tmpdir):
+    crate = ROCrate()
+    url = "https://zenodo.org/records/10782431/files/lysozyme_datasets.zip"
+    file_ = crate.add_file(url, validate_url=True)
+    assert file_.id == url
+    out_path = tmpdir / 'ro_crate_out'
+    crate.write(out_path)
+    out_crate = ROCrate(out_path)
+    out_file = out_crate.dereference(url)
+    props = out_file.properties()
+    assert props.get("encodingFormat") == "application/octet-stream"
+    assert "sdDatePublished" in props
+    with requests.head(url) as response:
+        assert props["sdDatePublished"] == response.headers.get("last-modified")