Cover missing title edge case

app.py

@@ -21,9 +21,6 @@ ps.set_index_parameters(index, 'nprobe=16,ht=512')
 
 
 def _recover_abstract(inverted_index):
-    if inverted_index is None: # edge case: no abstract
-        return ''
-    
     abstract_size = max([max(appearances) for appearances in inverted_index.values()])+1
 
     abstract = [None]*abstract_size
@@ -67,13 +64,23 @@ def format_response(neighbors, response):
 
         # collect attributes from openalex doc for the given openalex_id
         title = doc['title']
-        abstract = _recover_abstract(doc['abstract_inverted_index'])
+        # abstract = _recover_abstract(doc['abstract_inverted_index'])
+        abstract_inverted_index = doc['abstract_inverted_index']
         author_names = [authorship['author']['display_name'] for authorship in doc['authorships']]
         # journal_name = doc['primary_location']['source']['display_name']
         publication_year = doc['publication_year']
         citation_count = doc['cited_by_count']
         doi = doc['doi']
 
+        if title is None: # edge case: no title
+            title = 'No title'
+        
+        if abstract is None: # edge case: no abstract
+            abstract = 'No abstract'
+        else:
+            abstract = _recover_abstract(abstract_inverted_index)
+            abstract = abstract.replace('\n', '\\n').replace('\r', '\\r')
+
         # try to get journal name or else set it to None
         try:
             journal_name = doc['primary_location']['source']['display_name']