Query refactoring

README.txt

@@ -1,3 +1,6 @@
+Local configuration :
+	First of all copy the settings.ini to settings_local.ini and replace values by correct path
+
 Doxygen documentation generation :
 	doxygen
 

lodel/leapi/leobject.py

@@ -273,10 +273,107 @@ class LeObject(object):
     # at the end of the dyncode parse
     # @warning This method is deleted once the dynamic code loaded
     # @param field_list list : list of EmField instance
+    # @param cls
     @classmethod
     def _set__fields(cls, field_list):
         cls._fields = field_list
         
+    ## @brief Check that datas are valid for this type
+    # @param datas dict : key == field name value are field values
+    # @param complete bool : if True expect that datas provide values for all non internal fields
+    # @param allow_internal bool : if True don't raise an error if a field is internal
+    # @param cls
+    # @return Checked datas
+    # @throw LeApiDataCheckError if errors reported during check
+    @classmethod
+    def check_datas_value(cls, datas, complete = False, allow_internal = True):
+        err_l = dict() #Error storing
+        correct = set() #valid fields name
+        mandatory = set() #mandatory fields name
+        for fname, datahandler in cls._fields.items():
+            if allow_internal or not datahandler.is_internal():
+                correct.add(fname)
+                if complete and not hasattr(datahandler, 'default'):
+                    mandatory.add(fname)
+        provided = set(datas.keys())
+        # searching for unknow fields
+        for u_f in provided - correct:
+            #Here we can check if the field is invalid or rejected because
+            # it is internel
+            err_l[u_f] = AttributeError("Unknown or unauthorized field '%s'" % u_f)
+        # searching for missing mandatory fieldsa
+        for missing in mandatory - provided:
+            err_l[miss_field] = AttributeError("The data for field '%s' is missing" % missing)
+        #Checks datas
+        checked_datas = dict()
+        for name, value in [ (name, value) for name, value in datas.items() if name in correct ]:
+            dh = cls._fields[name]
+            res = dh.check_data_value(value)
+            checked_datas[name], err = res
+            if err:
+                err_l[name] = err
 
+        if len(err_l) > 0:
+            raise LeApiDataCheckError("Error while checking datas", err_l)
+        return checked_datas
+
+    ##@brief Check and prepare datas
+    # 
+    # @warning when complete = False we are not able to make construct_datas() and _check_data_consistency()
+    # 
+    # @param datas dict : {fieldname : fieldvalue, ...}
+    # @param complete bool : If True you MUST give all the datas
+    # @param allow_internal : Wether or not interal fields are expected in datas
+    # @param cls
+    # @return Datas ready for use
+    # @todo: complete is very unsafe, find a way to get rid of it
+    @classmethod
+    def prepare_datas(cls, datas, complete=False, allow_internal=True):
+        if not complete:
+            warnings.warn("\nActual implementation can make datas construction and consitency unsafe when datas are not complete\n")
+        ret_datas = cls.check_datas_value(datas, complete, allow_internal)
+        if isinstance(ret_datas, Exception):
+            raise ret_datas
+
+        if complete:
+            ret_datas = cls._construct_datas(ret_datas)
+            cls._check_datas_consistency(ret_datas)
+        return ret_datas
+
+    ## @brief Construct datas values
+    #
+    # @param cls
+    # @param datas dict : Datas that have been returned by LeCrud.check_datas_value() methods
+    # @return A new dict of datas
+    # @todo IMPLEMENTATION
+    @classmethod
+    def _construct_datas(cls, datas):
+        """
+        constructor = DatasConstructor(cls, datas, cls.fieldtypes())
+        ret = {
+                fname:constructor[fname]
+                for fname, ftype in cls.fieldtypes().items()
+                if not ftype.is_internal() or ftype.internal != 'autosql'
+        }
+        return ret
+        """
+        pass
+
+    ## @brief Check datas consistency
+    # 
+    # @warning assert that datas is complete
+    # @param cls
+    # @param datas dict : Datas that have been returned by LeCrud._construct_datas() method
+    # @throw LeApiDataCheckError if fails
+    @classmethod
+    def _check_datas_consistency(cls, datas):
+        err_l = []
+        err_l = dict()
+        for fname, dh in cls._fields.items():
+            ret = dh.check_data_consistency(cls, fname, datas)
+            if isinstance(ret, Exception):
+                err_l[fname] = ret
+
+        if len(err_l) > 0:
+            raise LeApiDataCheckError("Datas consistency checks fails", err_l)
 
-    

lodel/leapi/query.py

@@ -2,322 +2,191 @@
 
 import re
 from .leobject import LeObject, LeApiErrors, LeApiDataCheckError
-
+from lodel.plugin.hooks import LodelHook
 
 class LeQueryError(Exception):
     pass
 
 class LeQuery(object):
-
-    ##@brief The datasource object used for this query
-    datasource = None
-
-    ##@brief The available operators used in query definitions
-    query_operators = ['=', '<=', '>=', '!=', '<', '>', ' in ', ' not in ', ' like ', ' not like ']
-
-    ##@brief Constructor
-    # @param target_class EmClass : class of the object to query about
+    
+    ##@brief Hookname preffix
+    _hook_prefix = None
+    ##@brief arguments for the LeObject.check_data_value()
+    _data_check_args = { 'complete': False, 'allow_internal': False }
+
+    ##@brief Abstract constructor
+    # @param target_class LeObject : class of object the query is about
     def __init__(self, target_class):
+        if hook_prefix is None:
+            raise NotImplementedError("Asbtract class")
         if not issubclass(target_class, LeObject):
             raise TypeError("target class has to be a child class of LeObject")
-        self.target_class = target_class
-
-
-##@brief Class representing an Insert query
-class LeInsertQuery(LeQuery):
-
-    ##@brief Constructor
-    # @param target_class EmClass: class corresponding to the inserted object
-    # @param datas dict : datas to insert
-    def __init__(self, target_class, datas):
-        super().__init__(target_class)
-        self.datas = datas
-
-    ##@brief executes the insert query
-    # @return bool
-    # @TODO reactivate the LodelHooks call when this class is implemented
-    def execute(self):
-        datas = self.datas  # LodelHooks.call_hook('leapi_insert_pre', self.target_class, self.datas)
-        ret = self.__insert(**datas)
-        # ret = LodelHook.call_hook('leapi_insert_post', self.target_class, ret)
+        self.__target_class = target_class
+    
+    ##@brief Execute a query and return the result
+    # @param **datas
+    # @return the query result
+    # @see LeQuery.__query()
+    #
+    # @note maybe the datasource in not an argument but should be determined
+    #elsewhere
+    def execute(self, datasource, **datas):
+        if len(datas) > 0:
+            self.__target_class.check_datas_value(datas, **self._data_check_args)
+            self.__target_class.prepare_datas() #not yet implemented
+        if self._hook_prefix is None:
+            raise NotImplementedError("Abstract method")
+        LodelHook.call_hook(    self._hook_prefix+'_pre',
+                                self.__target_class,
+                                datas)
+        ret = self.__query(datasource, **datas)
+        ret = LodelHook.call_hook(  self._hook_prefix+'_post',
+                                    self.__target_class,
+                                    ret)
         return ret
+    
+    ##@brief Childs classes implements this method to execute the query
+    # @param **datas
+    # @return query result
+    def __query(self, **datas):
+        raise NotImplementedError("Asbtract method")
 
-    ##@brief calls the datasource to perform the insert command
-    # @param datas dict : formatted datas corresponding to the insert
-    # @return str : the uid of the inserted object
-    def __insert(self, **datas):
-        insert_datas = self.target_class.prepare_datas(datas, complete=True, allow_internal=True)
-        res = self.datasource.insert(self.target_class, **insert_datas)
-        return res
-
-
-##@brief Class representing an Abstract Filtered Query
 class LeFilteredQuery(LeQuery):
-
-    ##@brief Constructor
-    # @param target_class EmClass : Object of the query
-    def __init__(self, target_class):
+    
+    ##@brief The available operators used in query definitions
+    query_operators = [
+                        '=',
+                        '<=',
+                        '>=',
+                        '!=',
+                        '<',
+                        '>',
+                        ' in ',
+                        ' not in ',
+                        ' like ',
+                        ' not like ']
+
+    ##@brief Abtract constructor for queries with filter
+    # @param target_class LeObject : class of object the query is about
+    # @param query_filters list : list of string of query filters (or tuple 
+    #(FIELD, OPERATOR, VALUE) )
+    def __init__(self, target_class, query_filter):
         super().__init__(target_class)
+        ##@brief The query filter
+        self.__query_filter = None
+        self.set_qeury_filter(query_filter)
+    
+    ##@brief Set the query filter for a query
+    def set_query_filter(self, query_filter):
+        #
+        #   Query filter check & prepare should be done here
+        #
+        self.__query_filter = query_filter
+
+##@brief A query for insert a new object
+class LeInsertQuery(LeQuery):
+    
+    _hook_prefix = 'leapi_insert_'
+    _data_check_args = { 'complete': True, 'allow_internal': False }
 
-    ##@brief Validates the query filters
-    # @param query_filters list
-    # @return bool
-    # @raise LeQueryError if one of the filter is not valid
-    @classmethod
-    def validate_query_filters(cls, query_filters):
-        for query_filter in query_filters:
-            if query_filter[1] not in cls.query_operators:
-                raise LeQueryError("The operator %s is not valid." % query_filter[1])
-        return True
-
-    ##@brief Checks if a field is relational
-    # @param field str : Name of the field
-    # @return bool
-    @classmethod
-    def is_relational_field(cls, field):
-        return field.startswith('superior.') or field.startswith('subordinate.')
-
-
-##@brief Class representing a Get Query
-class LeGetQuery(LeFilteredQuery):
-
-    ##@brief Constructor
-    # @param target_class EmClass : main class
-    # @param query_filters
-    # @param field_list list
-    # @param order list : list of tuples corresponding to the fields used to sort the results
-    # @param group list : list of tuples corresponding to the fields used to group the results
-    # @param limit int : Maximum number of results to get
-    # @param offset int
-    # @param instanciate bool : if True, objects will be returned instead of dictionaries
-    def __init__(self, target_class, query_filters, field_list=None, order=None, group=None, limit=None, offset=0, instanciate=True):
+    def __init__(self, target_class):
         super().__init__(target_class)
-        self.query_filters = query_filters
-        self.default_field_list = []
-        self.field_list = field_list if field_list is not None else self.target_class.fieldnames()
-        self.order = order
-        self.group = group
-        self.limit = limit
-        self.offset = offset
-        self.instanciate = instanciate
-
-    ##@brief executes the query
-    # @return list
-    # @TODO activate LodelHook calls
-    def execute(self):
-        datas = self.datas  # LodelHook.call_hook('leapi_get_pre', self.target_object, self.datas)
-        ret = self.__get(**datas)
-        # ret = LodelHook.call_hook('leapi_get_post', self.target_object, ret)
-        return ret
-
-    def __get(self, **datas):
-        field_list = self.__prepare_field_list(self.field_list)
-
-        query_filters, relational_filters = self.__prepare_filters()
-
-        # Preparing the "order" parameters
-        if self.order:
-            order = self.__prepare_order()
-            if isinstance(order, Exception):
-                raise order  # can be buffered and raised later, but __prepare_filters raise when fails
-
-        # Preparing the "group" parameters
-        if self.group:
-            group = self.__prepare_order()
-            if isinstance(group, Exception):
-                raise group  # can be buffered and raised later
-
-        # checks the limit and offset values
-        if self.limit is not None and self.limit <= 0:
-            raise ValueError('Invalid limit given')
-
-        if self.offset is not None and self.offset < 0:
-            raise ValueError('Invalid offset given : %d' % self.offset)
-
-        results = self._datasource.select()  # TODO add the correct arguments for the datasource's method call
-        return results
-
-    ##@brief prepares the field list
-    # @return list
-    # @raise LeApiDataCheckError
-    def __prepare_field_list(self):
-        errors = dict()
-        ret_field_list = list()
-        for field in self.field_list:
-            if self.is_relational(field):
-                ret = self.__prepare_relational_field(field)
-            else:
-                ret = self.__check_field(field)
-
-            if isinstance(ret, Exception):
-                errors[field] = ret
-            else:
-                ret_field_list.append(ret)
-
-        if len(errors) > 0:
-            raise LeApiDataCheckError(errors)
-
-        return ret_field_list
-
-    ##@brief prepares a relational field
-    def __prepare_relational_field(self, field):
-        # TODO Implement the method
-        return field
-
-    ##@brief splits the filter string into a tuple (FIELD, OPERATOR, VALUE)
-    # @param filter str
-    # @return tuple
-    # @raise ValueError
-    def __split_filter(self, filter):
-        if self.query_re is None:
-            self.__compile_query_re()
-
-        matches = self.query_re.match(filter)
-        if not matches:
-            raise ValueError("The query_filter '%s' seems to be invalid" % filter)
-
-        result = (matches.group('field'), re.sub(r'\s', ' ', matches.group('operator')), matches.group('value').strip())
-        for r in result:
-            if len(r) == 0:
-                raise ValueError("The query_filter '%s' seems to be invalid" % filter)
-
-        return result
-
-    def __compile_query_re(self):
-        op_re_piece = '(?P<operator>(%s)' % self._query_operators[0].replace(' ', '\s')
-        for operator in self._query_operators[1:]:
-            op_re_piece += '|(%s)' % operator.replace(' ', '\s')
-        op_re_piece += ')'
-        self.query_re = re.compile('^\s*(?P<field>(((superior)|(subordinate))\.)?[a-z_][a-z0-9\-_]*)\s*'+op_re_piece+'\s*(?P<value>[^<>=!].*)\s*$', flags=re.IGNORECASE)
-
-    ##@brief checks if a field is in the target class of the query
-    # @param field str
-    # @return str
-    # @raise ValueError
-    def __check_field(self, field):
-        if field not in self.target_class.fieldnames():
-            return ValueError("No such field '%s' in %s" % (field, self.target_class))
-        return field
-
-    ##@brief Prepares the filters (relational and others)
-    # @return tuple
-    def __prepare_filters(self):
-        filters = list()
-        errors = dict()
-        res_filters = list()
-        rel_filters = list()
-
-        # Splitting in tuple if necessary
-        for filter in self.query_filters:
-            if len(filter) == 3 and not isinstance(filter, str):
-                filters.append(tuple(filter))
-            else:
-                filters.append(self.__split_filter(filter))
-
-        for field, operator, value in filters:
-            # TODO check the relation filters
-            ret = self.__check_field(field)
-            if isinstance(ret, Exception):
-                errors[field] = ret
-            else:
-                res_filters.append((ret, operator, value))
-
-        if len(errors) > 0:
-            raise LeApiDataCheckError("Error while preparing filters : ", errors)
-
-        return (res_filters, rel_filters)
-
-
-        datas = dict()
-        if LeFilteredQuery.validate_query_filters(self.query_filters):
-            datas['query_filters'] = self.query_filters
-        datas['target_class'] = self.target_class
-        return datas
-
-    ##@brief prepares the "order" parameters
-    # @return list
-    def __prepare_order(self):
-        errors = dict()
-        result = []
-        for order_field in self.order:
-            if not isinstance(order_field, tuple):
-                order_field = (order_field, 'ASC')
-            if len(order_field) != 2 or order_field[1].upper() not in ['ASC', 'DESC']:
-                errors[order_field] = ValueError("Expected a string or a tuple with (FIELDNAME, ['ASC'|'DESC']) but got : %s" % order_field)
-            else:
-                ret = self.target_class.check_field(order_field[0])
-                if isinstance(ret, Exception):
-                    errors[order_field] = ret
-            order_field = (order_field[0], order_field[1].upper())
-            result.append(order_field)
-
-        if len(errors) > 0:
-            raise LeApiErrors("Errors when preparing ordering fields", errors)
-        return result
-
+    
+    ## @brief Implements an insert query operations
+    # @param **datas : datas to be inserted
+    def __query(self, datasource, **datas):
+        pass
 
+##@brief A query to update datas for a given object
 class LeUpdateQuery(LeFilteredQuery):
-
-    def __init__(self, target_class, target_uid, query_filters):
-        super().__init__(target_class)
-        self.query_filters = query_filters
-        self.target_uid = target_uid
-
-    def execute(self):
-        # LodelHook.call_hook('leapi_update_pre', self.target_object, None)
-        ret = self.__update()
-        # ret = LodelHook.call_hook('leapi_update_post', self.target_object, ret)
-        return ret
-
-    ##@brief calls the datasource's update method and the corresponding hooks
-    # @return bool
-    # @TODO change the behavior in case of error in the update process
-    def __update(self):
-        updated_datas = self.__prepare()
-        ret = self.datasource.update(self.target_uid, **updated_datas)  # TODO add the correct arguments for the datasource's method
-        if ret == 1:
-            return True
-        else:
-            return False
-
-    ##@brief prepares the query_filters to be used as argument for the datasource's update method
-    def __prepare(self):
-        datas = dict()
-        if LeFilteredQuery.validate_query_filters(self.query_filters):
-            datas['query_filters'] = self.query_filters
-
-        datas['target_uid'] = self.target_uid
-        datas['target_class'] = self._target_class
-        return datas
-
-
+    
+    _hook_prefix = 'leapi_update_'
+    _data_check_args = { 'complete': True, 'allow_internal': False }
+
+    def __init__(self, target_class, query_filter):
+        super().__init__(target_class, query_filter)
+    
+    ##@brief Implements an update query
+    # @param **datas : datas to update
+    def __query(self, datasource, **datas):
+        pass
+
+##@brief A query to delete an object
 class LeDeleteQuery(LeFilteredQuery):
+    
+    _hook_prefix = 'leapi_delete_'
 
-    def __init__(self, target_class, target_uid, query_filters):
-        super().__init__(self._target_class)
-        self.target_uid = target_uid
-        self.query_filters = query_filters
-
-    def execute(self):
-        # LodelHook.call_hook('leapi_delete_pre', self.target_uid, None)
-        ret = self.__delete()
-        # ret = LodelHook.call('leapi_delete_post', self.target_object, ret)
-        return ret
-
-    ##@brief calls the datasource's delete method
-    # @return bool
-    # @TODO change the behavior in case of error in the update process
-    def __delete(self):
-        delete_datas = self.__prepare()
-        ret = self._datasource.delete(**delete_datas)
-        return ret
+    def __init__(self, target_class, query_filter):
+        super().__init__(target_class, query_filter)
 
-    def __prepare(self):
-        datas = dict()
-        if LeFilteredQuery.validate_query_filters(self.query_filters):
-            datas['query_filters'] = self.query_filters
+    ## @brief Execute the delete query
+    def execute(self, datasource):
+        super().execute()
+    
+    ##@brief Implements delete query operations
+    def __query(self, datasource):
+        pass
 
-        datas['target_uid'] = self.target_uid
-        datas['target_class'] = self._target_class
+class LeGetQuery(LeFilteredQuery):
+    
+    _hook_prefix = 'leapi_get_'
+
+    ##@brief Instanciate a new get query
+    # @param target_class LeObject : class of object the query is about
+    # @param query_filters list : list of string of query filters (or tuple 
+    #(FIELD, OPERATOR, VALUE) )
+    # @param field_list list|None : list of string representing fields see @ref leobject_filters
+    # @param order list : A list of field names or tuple (FIELDNAME, [ASC | DESC])
+    # @param group list : A list of field names or tuple (FIELDNAME, [ASC | DESC])
+    # @param limit int : The maximum number of returned results
+    # @param offset int : offset
+    def __init__(self, target_class, query_filter, **kwargs):
+        super().__init__(target_class, query_filter)
+        
+        ##@brief The fields to get
+        self.__field_list = None
+        ##@brief An equivalent to the SQL ORDER BY
+        self.__order = None
+        ##@brief An equivalent to the SQL GROUP BY
+        self.__group = None
+        ##@brief An equivalent to the SQL LIMIT x
+        self.__limit = None
+        ##@brief An equivalent to the SQL LIMIT x, OFFSET
+        self.__offset = 0
+        
+        # Checking kwargs and assigning default values if there is some
+        for argname in kwargs:
+            if argname not in ('order', 'group', 'limit', 'offset'):
+                raise TypeError("Unexpected argument '%s'" % argname)
+
+        if 'field_list' not in kwargs:
+            #field_list = target_class.get_field_list
+            pass
+        else:
+            #target_class.check_fields(kwargs['field_list'])
+            field_list = kwargs['field_list']
+        if 'order' in kwargs:
+            #check kwargs['order']
+            self.__order = kwargs['order']
+        if 'group' in kwargs:
+            #check kwargs['group']
+            self.__group = kwargs['group']
+        if 'limit' in kwargs:
+            try:
+                self.__limit = int(kwargs[limit])
+                if self.__limit <= 0:
+                    raise ValueError()
+            except ValueError:
+                raise ValueError("limit argument expected to be an interger > 0")
+        if 'offset' in kwargs:
+            try:
+                self.__offset = int(kwargs['offset'])
+                if self.__offset < 0:
+                    raise ValueError()
+            except ValueError:
+                raise ValueError("offset argument expected to be an integer >= 0")
+    
+    ##@brief Execute the get query
+    def execute(self, datasource):
+        super().execute(datasource)
 
-        return datas