Makes documentmetadata value a textfield

mayan/apps/metadata/models.py

@@ -157,8 +157,8 @@ class DocumentMetadata(models.Model):
     metadata_type = models.ForeignKey(
         MetadataType, on_delete=models.CASCADE, verbose_name=_('Type')
     )
-    value = models.CharField(
-        blank=True, db_index=True, max_length=255, null=True,
+    value = models.TextField(
+        blank=True, db_index=True, null=True,
         verbose_name=_('Value')
     )
 

mayan/apps/metadata/tests/test_models.py

@@ -190,3 +190,22 @@ class MetadataTestCase(BaseTestCase):
         self.metadata_type.lookup = 'test1,test2'
         self.metadata_type.save()
         self.metadata_type.validate_value(document_type=None, value='test1')
+
+    def test_long_value_for_metadata(self):
+        """
+        asserts that DocumentMetadata.value can store more than 255 chars
+        """
+        very_long_string = (u'Mayan EDMS is a Free Open Source Electronic '+
+                'Document Management System, coded in the Python language '+
+                'using the Django web application framework and released '+
+                'under the Apache 2.0 License. It provides an electronic '+
+                'vault or repository for electronic documents.') # 258 chars
+        document_metadata = DocumentMetadata(
+            document=self.document, metadata_type=self.metadata_type,
+            value=very_long_string
+        )
+        document_metadata.full_clean()
+        document_metadata.save()
+        self.assertEqual(very_long_string, document_metadata.value)
+        
+