Add option for parsing of date from filename (and associated tests)

paperless.conf.example

@@ -122,6 +122,14 @@ PAPERLESS_EMAIL_SECRET=""
 # "true", the document will instead be opened in the browser, if possible.
 #PAPERLESS_INLINE_DOC="false"
 
+# By default, paperless will check the document text for document date information.
+# Uncomment the line below to enable checking the document filename for date
+# information. The date order can be set to any option as specified in
+# https://dateparser.readthedocs.io/en/latest/#settings. The filename will be
+# checked first, and if nothing is found, the document text will be checked
+# as normal.
+#PAPERLESS_FILENAME_DATE_ORDER="YMD"
+
 #
 # The following values use sensible defaults for modern systems, but if you're
 # running Paperless on a low-resource device (like a Raspberry Pi), modifying

src/paperless/settings.py

@@ -292,3 +292,4 @@ FY_END = os.getenv("PAPERLESS_FINANCIAL_YEAR_END")
 
 # Specify the default date order (for autodetected dates)
 DATE_ORDER = os.getenv("PAPERLESS_DATE_ORDER", "DMY")
+FILENAME_DATE_ORDER = os.getenv("PAPERLESS_FILENAME_DATE_ORDER")

src/paperless_tesseract/parsers.py

@@ -34,6 +34,7 @@ class RasterisedDocumentParser(DocumentParser):
     THREADS = int(settings.OCR_THREADS) if settings.OCR_THREADS else None
     UNPAPER = settings.UNPAPER_BINARY
     DATE_ORDER = settings.DATE_ORDER
+    FILENAME_DATE_ORDER = settings.FILENAME_DATE_ORDER
     DEFAULT_OCR_LANGUAGE = settings.OCR_LANGUAGE
     OCR_ALWAYS = settings.OCR_ALWAYS
 
@@ -206,7 +207,30 @@ class RasterisedDocumentParser(DocumentParser):
         date = None
         datestring = None
 
+        if self.FILENAME_DATE_ORDER:
+            self.log("info", "Checking document title for date")
+            text = os.path.basename(self.document_path)
+            for m in re.finditer(DATE_REGEX, text):
+                datestring = m.group(0)
                 try:
+                    date = dateparser.parse(
+                        datestring,
+                        settings={'DATE_ORDER': self.FILENAME_DATE_ORDER,
+                                  'PREFER_DAY_OF_MONTH': 'first',
+                                  'RETURN_AS_TIMEZONE_AWARE': True})
+                except TypeError:
+                    # Skip all matches that do not parse to a proper date
+                    continue
+
+                if date is not None:
+                    self.log("info",
+                             "Detected document date {} based on string {} "
+                             "from document title"
+                             "".format(date.isoformat(), datestring))
+                    return date
+
+        try:
+            self.log('info', "Checking document text for date")
             text = self.get_text()
         except ParseError as e:
             return None

src/paperless_tesseract/tests/test_date.py

@@ -425,4 +425,72 @@ class TestDate(TestCase):
             datetime.datetime(2017, 12, 31, 0, 0,
                               tzinfo=tz.gettz(settings.TIME_ZONE))
         )
+
+    @mock.patch(
+        "paperless_tesseract.parsers.RasterisedDocumentParser.SCRATCH",
+        SCRATCH
+    )
+    def test_filename_date_1_pdf(self):
+        input_file = os.path.join(self.SAMPLE_FILES,
+                                  "tests_date_in_filename_2018-03-20_1.pdf")
+        document = RasterisedDocumentParser(input_file)
+        document.FILENAME_DATE_ORDER = 'YMD'
+        document.get_text()
+        date = document.get_date()
+        self.assertEqual(document._is_ocred(), True)
+        self.assertEqual(
+            date,
+            datetime.datetime(2018, 3, 20, 0, 0,
+                              tzinfo=tz.gettz(settings.TIME_ZONE))
+        )
+
+    @mock.patch(
+        "paperless_tesseract.parsers.RasterisedDocumentParser.SCRATCH",
+        SCRATCH
+    )
+    def test_filename_date_1_png(self):
+        input_file = os.path.join(self.SAMPLE_FILES,
+                                  "tests_date_in_filename_2018-03-20_1.png")
+        document = RasterisedDocumentParser(input_file)
+        document.FILENAME_DATE_ORDER = 'YMD'
+        date = document.get_date()
+        self.assertEqual(document._is_ocred(), False)
+        self.assertEqual(
+            date,
+            datetime.datetime(2018, 3, 20, 0, 0,
+                              tzinfo=tz.gettz(settings.TIME_ZONE))
+        )
+
+    @mock.patch(
+        "paperless_tesseract.parsers.RasterisedDocumentParser.SCRATCH",
+        SCRATCH
+    )
+    def test_filename_date_2_pdf(self):
+        input_file = os.path.join(self.SAMPLE_FILES,
+                                  "2013-12-11_tests_date_in_filename_2.pdf")
+        document = RasterisedDocumentParser(input_file)
+        document.FILENAME_DATE_ORDER = 'YMD'
+        date = document.get_date()
+        self.assertEqual(document._is_ocred(), True)
+        self.assertEqual(
+            date,
+            datetime.datetime(2013, 12, 11, 0, 0,
+                              tzinfo=tz.gettz(settings.TIME_ZONE))
+        )
+
+    @mock.patch(
+        "paperless_tesseract.parsers.RasterisedDocumentParser.SCRATCH",
+        SCRATCH
+    )
+    def test_filename_date_2_png(self):
+        input_file = os.path.join(self.SAMPLE_FILES,
+                                  "2013-12-11_tests_date_in_filename_2.png")
+        document = RasterisedDocumentParser(input_file)
+        document.FILENAME_DATE_ORDER = 'YMD'
+        date = document.get_date()
+        self.assertEqual(document._is_ocred(), False)
+        self.assertEqual(
+            date,
+            datetime.datetime(2013, 12, 11, 0, 0,
+                              tzinfo=tz.gettz(settings.TIME_ZONE))
         )