Ajout filtres API REST

parlapi/rest/endpoint.py

@@ -2,15 +2,27 @@
 
 import collections
 from copy import copy
+from datetime import datetime
 
-from flask import abort, jsonify, request
+from flask import abort, json, jsonify, request
 from sqlalchemy.inspection import inspect
 
 from .schema import SchemaFactory
 
 
+class EndpointException(Exception):
+    pass
+
+
 class Endpoint(object):
 
+    _casters = {
+        'Integer': int,
+        'Unicode': lambda x: x,
+        'Boolean': lambda x: x.lower() in ('true', 'yes', '1'),
+        'Date': lambda x: datetime.strptime(x, '%Y-%m-%d').date()
+    }
+
     def __init__(self, api, ma, model, description=None, hidden=False):
         self.api = api
         self.ma = ma
@@ -37,6 +49,11 @@ class Endpoint(object):
 
         return Paginated
 
+    def _make_error(self, message, code=400):
+        res = jsonify({ '_error': message, '_code': code })
+        res.status_code = code
+        return res
+
     def describe(self):
         mapper = inspect(self.model)
 
@@ -67,6 +84,55 @@ class Endpoint(object):
 
         return jsonify(desc)
 
+    def _cast_value(self, value, typename):
+        if typename not in self._casters:
+            raise EndpointException('No type caster for {}'.format(typename))
+        try:
+            return self._casters[typename](value)
+        except ValueError:
+            raise EndpointException('Could not cast value to {}: {}'.format(typename, value))
+
+    def _apply_filters(self, query, args):
+        if not len(args):
+            return query
+
+        columns = { c.name: type(c.type).__name__ for c in inspect(self.model).columns }
+        filters = []
+
+        for colname, value in args.items():
+            op = 'eq'
+            if colname.find('__') >= 0:
+                colname, op = colname.rsplit('__', 1)
+            if colname not in columns:
+                raise EndpointException('Unknown column name: {}'.format(colname))
+
+            col = getattr(self.model, colname)
+            if op in ('eq', 'ne', 'gt', 'lt', 'gte', 'lte'):
+                value = self._cast_value(value, columns[colname])
+
+                if op == 'eq':
+                    filters.append(col == value)
+                elif op == 'ne':
+                    filters.append(col != value)
+                elif op == 'gt':
+                    filters.append(col > value)
+                elif op == 'lt':
+                    filters.append(col < value)
+                elif op == 'gte':
+                    filters.append(col >= value)
+                elif op == 'lte':
+                    filters.append(col <= value)
+            elif op == 'isnull':
+                null = self._cast_value(value, 'Boolean')
+                if null:
+                    filters.append(col == None)
+                else:
+                    filters.append(col != None)
+            else:
+                raise EndpointException('Unknown operator: {}'.format(op))
+
+        return query.filter(*filters)
+
     def list(self):
         args = request.args
         forward_qs = {}
@@ -75,6 +141,12 @@ class Endpoint(object):
         item_schema, query = self._schema(mode='list')
         list_schema = self._paginate(item_schema)
 
+        # Handle filters
+        try:
+            query = self._apply_filters(query, { k: v for k, v in args.items() if k not in ('search', 'page', 'page_size') })
+        except EndpointException, e:
+            return self._make_error(e.message)
+
         # Handle search
         if args.get('search', None) and hasattr(query, 'search'):
             query = query.search(args['search'])