Support JSON download

app/api/views/download/factory.py

@@ -19,6 +19,7 @@ def create_repository(project) -> repositories.BaseRepository:
 def create_writer(format: str) -> Type[writer.BaseWriter]:
     mapping = {
         catalog.CSV.name: writer.CsvWriter,
+        catalog.JSON.name: writer.JSONWriter,
         catalog.JSONL.name: writer.JSONLWriter,
         catalog.FastText.name: writer.FastTextWriter,
     }

app/api/views/download/writer.py

@@ -5,6 +5,7 @@ import json
 import os
 import uuid
 import zipfile
+from collections import defaultdict
 from typing import Dict, Iterable, Iterator, List
 
 from .data import Record
@@ -80,17 +81,51 @@ class CsvWriter(BaseWriter):
 
     def create_line(self, record) -> Dict:
         return {
+            'id': record.id,
             'data': record.data,
             'label': '#'.join(record.label),
             **record.metadata
         }
 
     def create_header(self, records: List[Record]) -> Iterable[str]:
-        header = ['data', 'label']
+        header = ['id', 'data', 'label']
         header += list(itertools.chain(*[r.metadata.keys() for r in records]))
         return header
 
 
+class JSONWriter(BaseWriter):
+    extension = 'json'
+
+    def write(self, records: Iterator[Record]) -> str:
+        writers = {}
+        contents = defaultdict(list)
+        for record in records:
+            filename = os.path.join(self.tmpdir, f'{record.user}.{self.extension}')
+            if filename not in writers:
+                f = open(filename, mode='a')
+                writers[filename] = f
+            line = self.create_line(record)
+            contents[filename].append(line)
+
+        for filename, f in writers.items():
+            content = contents[filename]
+            json.dump(content, f)
+            f.close()
+
+        save_file = self.write_zip(writers)
+        for file in writers:
+            os.remove(file)
+        return save_file
+
+    def create_line(self, record) -> Dict:
+        return {
+            'id': record.id,
+            'data': record.data,
+            'label': record.label,
+            **record.metadata
+        }
+
+
 class JSONLWriter(LineWriter):
     extension = 'jsonl'