Implementation of Query filter

This allows to search by a keyword. Example:
```
/search-api/documents?filter={"query":"diffraction"}
```

This should returns the document that are related to diffraction

datagateway_api/src/api_start_utils.py

@@ -152,8 +152,7 @@ def create_api_endpoints(flask_app, api, specs):
     # DataGateway API endpoints
     if Config.config.datagateway_api is not None:
         datagateway_api_spec = next(
-            (spec for spec in specs if spec.title == "DataGateway API"),
-            None,
+            (spec for spec in specs if spec.title == "DataGateway API"), None,
         )
         try:
             backend_type = flask_app.config["TEST_BACKEND"]
@@ -224,8 +223,7 @@ def create_api_endpoints(flask_app, api, specs):
 
         # Session endpoint
         session_endpoint_resource = session_endpoints(
-            backend,
-            client_pool=icat_client_pool,
+            backend, client_pool=icat_client_pool,
         )
         api.add_resource(
             session_endpoint_resource,
@@ -236,8 +234,7 @@ def create_api_endpoints(flask_app, api, specs):
 
         # Table specific endpoints
         instrument_facility_cycle_resource = instrument_facility_cycles_endpoint(
-            backend,
-            client_pool=icat_client_pool,
+            backend, client_pool=icat_client_pool,
         )
         api.add_resource(
             instrument_facility_cycle_resource,
@@ -247,8 +244,7 @@ def create_api_endpoints(flask_app, api, specs):
         datagateway_api_spec.path(resource=instrument_facility_cycle_resource, api=api)
 
         count_instrument_facility_cycle_res = count_instrument_facility_cycles_endpoint(
-            backend,
-            client_pool=icat_client_pool,
+            backend, client_pool=icat_client_pool,
         )
         api.add_resource(
             count_instrument_facility_cycle_res,
@@ -258,8 +254,7 @@ def create_api_endpoints(flask_app, api, specs):
         datagateway_api_spec.path(resource=count_instrument_facility_cycle_res, api=api)
 
         instrument_investigation_resource = instrument_investigation_endpoint(
-            backend,
-            client_pool=icat_client_pool,
+            backend, client_pool=icat_client_pool,
         )
         api.add_resource(
             instrument_investigation_resource,
@@ -270,8 +265,7 @@ def create_api_endpoints(flask_app, api, specs):
         datagateway_api_spec.path(resource=instrument_investigation_resource, api=api)
 
         count_instrument_investigation_res = count_instrument_investigation_endpoint(
-            backend,
-            client_pool=icat_client_pool,
+            backend, client_pool=icat_client_pool,
         )
         api.add_resource(
             count_instrument_investigation_res,
@@ -289,8 +283,7 @@ def create_api_endpoints(flask_app, api, specs):
     # Search API endpoints
     if Config.config.search_api is not None:
         search_api_spec = next(
-            (spec for spec in specs if spec.title == "Search API"),
-            None,
+            (spec for spec in specs if spec.title == "Search API"), None,
         )
         search_api_extension = Config.config.search_api.extension
         search_api_entity_endpoints = {

datagateway_api/src/datagateway_api/icat/filters.py

@@ -7,7 +7,6 @@
     IncludeFilter,
     LimitFilter,
     OrderFilter,
-    ScoringQueryFilter,
     SkipFilter,
     WhereFilter,
 )
@@ -57,22 +56,16 @@ def create_filter(self):
         elif self.operation == "ilike":
             self.field = f"UPPER({self.field})"
             where_filter = self.create_condition(
-                self.field,
-                "like",
-                f"UPPER('%{self.value}%')",
+                self.field, "like", f"UPPER('%{self.value}%')",
             )
         elif self.operation == "nlike":
             where_filter = self.create_condition(
-                self.field,
-                "not like",
-                f"%{self.value}%",
+                self.field, "not like", f"%{self.value}%",
             )
         elif self.operation == "nilike":
             self.field = f"UPPER({self.field})"
             where_filter = self.create_condition(
-                self.field,
-                "not like",
-                f"UPPER('%{self.value}%')",
+                self.field, "not like", f"UPPER('%{self.value}%')",
             )
         elif self.operation == "lt":
             where_filter = self.create_condition(self.field, "<", self.value)
@@ -110,9 +103,7 @@ def create_filter(self):
             where_filter = self.create_condition(self.field, "not in", self.value)
         elif self.operation == "between":
             where_filter = self.create_condition(
-                self.field,
-                "between",
-                f"'{self.value[0]}' and '{self.value[1]}'",
+                self.field, "between", f"'{self.value[0]}' and '{self.value[1]}'",
             )
         elif self.operation == "regexp":
             where_filter = self.create_condition(self.field, "regexp", self.value)
@@ -230,8 +221,7 @@ def apply_filter(self, query):
                     PythonICATOrderFilter.join_specs[join_field_str] = "LEFT JOIN"
 
                 log.debug(
-                    "Setting query join specs: %s",
-                    PythonICATOrderFilter.join_specs,
+                    "Setting query join specs: %s", PythonICATOrderFilter.join_specs,
                 )
                 try:
                     query.setJoinSpecs(PythonICATOrderFilter.join_specs)

datagateway_api/src/search_api/filters.py

@@ -8,7 +8,7 @@
     PythonICATLimitFilter,
     PythonICATSkipFilter,
     PythonICATWhereFilter,
-    ScoringQueryFilter
+    ScoringQueryFilter,
 )
 from datagateway_api.src.search_api.models import PaNOSCAttribute
 from datagateway_api.src.search_api.panosc_mappings import mappings
@@ -162,13 +162,15 @@ def __init__(self, limit_value):
     def apply_filter(self, query):
         return super().apply_filter(query.icat_query.query)
 
+
 class SearchAPIScoringFilter(ScoringQueryFilter):
     def __init__(self, query_value):
         super().__init__(query_value)
 
     def apply_filter(self, query):
         return
 
+
 class SearchAPIIncludeFilter(PythonICATIncludeFilter):
     def __init__(self, included_filters, panosc_entity_name):
         self.included_filters = included_filters

datagateway_api/src/search_api/helpers.py

@@ -202,9 +202,7 @@ def get_files(entity_name, pid, filters):
 
     log.info("Getting files of dataset (PID: %s), using request's filters", pid)
     log.debug(
-        "Entity Name: %s, Filters: %s",
-        entity_name,
-        filters,
+        "Entity Name: %s, Filters: %s", entity_name, filters,
     )
 
     filters.append(SearchAPIWhereFilter("dataset.pid", pid, "eq"))
@@ -226,13 +224,10 @@ def get_files_count(entity_name, filters, pid):
     """
 
     log.info(
-        "Getting number of files for dataset (PID: %s), using request's filters",
-        pid,
+        "Getting number of files for dataset (PID: %s), using request's filters", pid,
     )
     log.debug(
-        "Entity Name: %s, Filters: %s",
-        entity_name,
-        filters,
+        "Entity Name: %s, Filters: %s", entity_name, filters,
     )
 
     filters.append(SearchAPIWhereFilter("dataset.pid", pid, "eq"))

datagateway_api/src/search_api/query_filter_factory.py

@@ -6,6 +6,7 @@
 from datagateway_api.src.search_api.filters import (
     SearchAPIIncludeFilter,
     SearchAPILimitFilter,
+    SearchAPIScoringFilter,
     SearchAPISkipFilter,
     SearchAPIWhereFilter,
 )
@@ -62,6 +63,9 @@ def get_query_filter(request_filter, entity_name=None, related_entity_name=None)
                 elif filter_name == "skip":
                     log.info("skip JSON object found")
                     query_filters.append(SearchAPISkipFilter(filter_input))
+                elif filter_name == "query":
+                    log.info("query JSON object found")
+                    query_filters.append(SearchAPIScoringFilter(filter_input))
                 else:
                     raise FilterError(
                         "No valid filter name given within filter query param:"