Get item links

src/solid/solid_api.py

@@ -5,7 +5,7 @@
 from httpx import Response, HTTPStatusError
 
 from solid.auth import Auth
-from solid.utils.api_util import get_root_url, LINK, get_parent_url, get_item_name
+from solid.utils.api_util import get_root_url, LINK, get_parent_url, get_item_name, get_links_from_response
 from solid.utils.folder_utils import parse_folder_response
 
 
@@ -215,8 +215,26 @@ def read_folder(self, url, options: ReadFolderOptions = ReadFolderOptions()) ->
 
         return parsed_folder
 
-    def get_item_links(self, url, options: Dict = None) -> Response:
-        raise Exception('Not implemented')
+    def get_item_links(self, url, options: Dict = {}) -> Links:
+        if not self.item_exists(url):
+            raise Exception(f'Item not found: {url}')
+
+        options.update({
+            "links": LINKS.INCLUDE_POSSIBLE,
+            "withAcl": True,
+            "withMeta": True,
+        })
+
+        if (options['links'] == LINKS.EXCLUDE):
+            raise Exception(f'Invalid option LINKS.EXCLUDE for getItemLinks')
+
+        response = self.head(url)
+        links = get_links_from_response(response)
+        if (options['links'] == LINKS.INCLUDE):
+            if (not options.withAcl): del links['acl']
+            if (not options.withMeta): del links['meta']
+
+        return links
 
     def copy_file(self, _from, to, options: WriteOptions = None) -> Response:
         raise Exception('Not implemented')

src/solid/utils/api_util.py

@@ -1,5 +1,6 @@
 from enum import Enum
-from typing import List
+from typing import List, Dict
+import re
 
 
 class LINK(Enum):
@@ -59,3 +60,107 @@ def are_folders(urls: List) -> bool:
 
 def are_files(urls: List) -> bool:
     pass
+
+def get_links_from_response(response) -> dict:
+    link_header = response.headers.get('link')
+    if (not link_header) or (link_header == ''):
+        return {}
+    else:
+        return parse_link_header(link_header, response.url)
+
+def parse_link_header(link_header: str, item_url) -> Dict:
+    link_dict = {}
+    link_header_list = parse_link_header_to_array(link_header)
+    if len(link_header_list) > 0:
+        for link in link_header_list:
+            url = link[link.index('<')+ 1:link.index('>')]
+            original_rel = link[link.index('rel="')+ 5:link.rindex('"')]
+            if (original_rel.lower() == 'describedby'):
+                rel = 'meta'
+            else:
+                rel = original_rel
+
+            if rel in ['meta', 'acl']:
+                link_dict[rel] = url_join(url, item_url)
+
+    return link_dict
+
+def parse_link_header_to_array(link_header: str) -> List:
+    if (not link_header): return
+    linkexp = '<[^>]*>\s*(\s*;\s*[^()<>@,;:"/[\]?={} \t]+=(([^\(\)<>@,;:"\/\[\]\?={} \t]+)|("[^"]*")))*(,|$)'
+    match = re.finditer(linkexp, link_header)
+    links = [x.group() for x in match]
+    return links
+
+def url_join(given, base) -> str:
+  base = str(base)
+  base_hash = base.find('#')
+  if (base_hash > 0):
+    base = base[0:base_hash]
+
+  if (len(given) == 0):
+    return base
+
+  if (given.find('#') == 0):
+    return base + given
+
+  colon = given.find(':')
+  if (colon >= 0) :
+    return given
+
+  base_colon = base.find(':')
+  if (len(base) == 0) :
+    return given
+
+  if (base_colon < 0) :
+    return given
+
+  if (+ base_colon + 1):
+      end_index = +base_colon + 1
+  else:
+      end_index = 9e9
+
+  base_scheme = base[:end_index]
+  if (given.find('//') == 0) :
+    return base_scheme + given
+
+  if (base.find('//', base_colon) == base_colon + 1):
+    base_single = base.find('/', base_colon + 3)
+    if (base_single < 0):
+      if (len(base) - base_colon - 3 > 0):
+        return base + '/' + given
+      else:
+        return base_scheme + given
+
+  else:
+    base_single = base.find('/', base_colon + 1)
+    if (base_single < 0):
+      if (len(base) - base_colon - 1 > 0) :
+        return base + '/' + given
+      else:
+        return base_scheme + given
+
+  if (given.find('/') == 0) :
+    return base[:base_single] + given
+
+  path = base[base_single:]
+  try:
+    last_slash = path.rindex('/')
+  except:
+    return base_scheme + given
+
+  if (last_slash >= 0 and last_slash < len(path) - 1) :
+    if (+last_slash + 1):
+        end_index = +last_slash + 1
+    else:
+        end_index = 9e9
+    path = path[:end_index]
+
+  path += given
+  while (re.match("[^\/]*\/\.\.\/", path)) :
+    path = re.sub("[^\/]*\/\.\.\/", '', path, 1)
+
+  path = re.sub("\.\/", '', path)
+  path = re.sub("\/\.$", '/', path)
+  return base[:base_single] + path
+

tests/integration_test_solid_api.py

@@ -167,6 +167,6 @@ def test_file():
     lines = resp.text.split('\n')
     assert lines[4] == '<> dct:title "This is a test file"; contact:personalTitle "Dr.".'
 
-
-
-
+    # get item links
+    links = api.get_item_links(patchedUrl)
+    assert links == {'acl': f'{patchedUrl}.acl', 'meta': f'{patchedUrl}.meta'}