src/*: code refactor and comments

Some refactoring in the database utilitie functions.

src/datasources/db/cargobikeAPI.ts

@@ -26,7 +26,7 @@ import { Equipment } from '../../model/Equipment';
 import { Engagement } from '../../model/Engagement';
 import { Provider } from '../../model/Provider';
 import { TimeFrame } from '../../model/TimeFrame';
-import { ActionLogger, deleteEntity, getAllEntity, LockUtils } from './utils';
+import { ActionLogger, DBUtils, LockUtils } from './utils';
 import { EquipmentType } from '../../model/EquipmentType';
 import { BikeEventType } from '../../model/BikeEventType';
 import { UserInputError } from 'apollo-server-express';
@@ -43,7 +43,7 @@ export class CargoBikeAPI extends DataSource {
     }
 
     async getCargoBikes (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, CargoBike, 'cb', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, CargoBike, 'cb', offset, limit);
     }
 
     /**
@@ -192,11 +192,11 @@ export class CargoBikeAPI extends DataSource {
     }
 
     async deleteBikeEventType (id: number, userId: number) {
-        return await deleteEntity(this.connection, BikeEventType, 'bet', id, userId);
+        return await DBUtils.deleteEntity(this.connection, BikeEventType, 'bet', id, userId);
     }
 
     async deleteBikeEvent (id: number, userId: number) {
-        return await deleteEntity(this.connection, BikeEvent, 'be', id, userId);
+        return await DBUtils.deleteEntity(this.connection, BikeEvent, 'be', id, userId);
     }
 
     async cargoBikeByEventId (id: number) {
@@ -270,11 +270,11 @@ export class CargoBikeAPI extends DataSource {
     }
 
     async bikeEventTypes (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, BikeEventType, 'bet', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, BikeEventType, 'bet', offset, limit);
     }
 
     async bikeEvents (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, BikeEvent, 'be', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, BikeEvent, 'be', offset, limit);
     }
 
     async bikeEventTypeById (id: number) {
@@ -408,7 +408,7 @@ export class CargoBikeAPI extends DataSource {
     }
 
     async deleteEquipment (id: number, userId: number) {
-        return await deleteEntity(this.connection, Equipment, 'e', id, userId);
+        return await DBUtils.deleteEntity(this.connection, Equipment, 'e', id, userId);
     }
 
     async getEquipment (offset: number, limit: number) {
@@ -462,7 +462,7 @@ export class CargoBikeAPI extends DataSource {
     }
 
     async deleteEquipmentType (id:number, userId: number) {
-        return await deleteEntity(this.connection, EquipmentType, 'et', id, userId);
+        return await DBUtils.deleteEntity(this.connection, EquipmentType, 'et', id, userId);
     }
 
     async equipmentTypeById (id: number) {

src/datasources/db/contactinformationAPI.ts

@@ -21,7 +21,7 @@ import { DataSource } from 'apollo-datasource';
 import { Connection, EntityManager, getConnection } from 'typeorm';
 import { ContactInformation } from '../../model/ContactInformation';
 import { Person } from '../../model/Person';
-import { ActionLogger, deleteEntity, getAllEntity, LockUtils } from './utils';
+import { ActionLogger, DBUtils, LockUtils } from './utils';
 import { GraphQLError } from 'graphql';
 import { LendingStation } from '../../model/LendingStation';
 
@@ -33,7 +33,7 @@ export class ContactInformationAPI extends DataSource {
     }
 
     async contactInformation (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, ContactInformation, 'ci', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, ContactInformation, 'ci', offset, limit);
     }
 
     async contactInformationById (id: number) {
@@ -83,11 +83,11 @@ export class ContactInformationAPI extends DataSource {
     }
 
     async deletePerson (id: number, userId: number) {
-        return await deleteEntity(this.connection, Person, 'p', id, userId);
+        return await DBUtils.deleteEntity(this.connection, Person, 'p', id, userId);
     }
 
     async persons (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, Person, 'p', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, Person, 'p', offset, limit);
     }
 
     async personById (id: number) {
@@ -161,7 +161,7 @@ export class ContactInformationAPI extends DataSource {
     }
 
     async deleteContactInformation (id: number, userId: number) {
-        return await deleteEntity(this.connection, ContactInformation, 'ci', id, userId);
+        return await DBUtils.deleteEntity(this.connection, ContactInformation, 'ci', id, userId);
     }
 
     async contactInformationByPersonId (id: number) {

src/datasources/db/lendingstationAPI.ts

@@ -24,7 +24,7 @@ import { Connection, EntityManager, getConnection } from 'typeorm';
 import { CargoBike } from '../../model/CargoBike';
 import { LendingStation } from '../../model/LendingStation';
 import { TimeFrame } from '../../model/TimeFrame';
-import { ActionLogger, deleteEntity, genDateRange, getAllEntity, LockUtils } from './utils';
+import { ActionLogger, genDateRange, DBUtils, LockUtils } from './utils';
 
 export class LendingStationAPI extends DataSource {
     connection : Connection
@@ -45,7 +45,7 @@ export class LendingStationAPI extends DataSource {
      * get all lendingStations
      */
     async lendingStations (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, LendingStation, 'ls', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, LendingStation, 'ls', offset, limit);
     }
 
     /**
@@ -74,7 +74,7 @@ export class LendingStationAPI extends DataSource {
     }
 
     async timeFrames (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, TimeFrame, 'tf', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, TimeFrame, 'tf', offset, limit);
     }
 
     async timeFramesByCargoBikeId (id: number) {
@@ -179,7 +179,7 @@ export class LendingStationAPI extends DataSource {
     }
 
     async deleteLendingStationById (id: number, userId: number) {
-        return await deleteEntity(this.connection, LendingStation, 'ls', id, userId);
+        return await DBUtils.deleteEntity(this.connection, LendingStation, 'ls', id, userId);
     }
 
     async createTimeFrame (timeFrame: any) {
@@ -257,6 +257,6 @@ export class LendingStationAPI extends DataSource {
     }
 
     async deleteTimeFrame (id: number, userId: number) {
-        return await deleteEntity(this.connection, TimeFrame, 'tf', id, userId);
+        return await DBUtils.deleteEntity(this.connection, TimeFrame, 'tf', id, userId);
     }
 }

src/datasources/db/participantAPI.ts

@@ -23,7 +23,7 @@ import { ContactInformation } from '../../model/ContactInformation';
 import { Engagement } from '../../model/Engagement';
 import { Participant } from '../../model/Participant';
 import { EngagementType } from '../../model/EngagementType';
-import { ActionLogger, deleteEntity, genDateRange, getAllEntity, LockUtils } from './utils';
+import { ActionLogger, DBUtils, genDateRange, LockUtils } from './utils';
 import { UserInputError } from 'apollo-server-express';
 import { GraphQLError } from 'graphql';
 
@@ -43,7 +43,7 @@ export class ParticipantAPI extends DataSource {
     }
 
     async getParticipants (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, Participant, 'p', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, Participant, 'p', offset, limit);
     }
 
     async participantByEngagementId (id: number) {
@@ -110,7 +110,7 @@ export class ParticipantAPI extends DataSource {
     }
 
     async engagements (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, Engagement, 'e', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, Engagement, 'e', offset, limit);
     }
 
     async engagementById (id: number) {
@@ -130,7 +130,7 @@ export class ParticipantAPI extends DataSource {
     }
 
     async engagementTypes (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, Engagement, 'e', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, Engagement, 'e', offset, limit);
     }
 
     async engagementTypeByEngagementId (id: number) {
@@ -223,7 +223,7 @@ export class ParticipantAPI extends DataSource {
     }
 
     async deleteParticipant (id: number, userId: number) {
-        return await deleteEntity(this.connection, Participant, 'p', id, userId);
+        return await DBUtils.deleteEntity(this.connection, Participant, 'p', id, userId);
     }
 
     async createEngagement (engagement: any) {
@@ -292,7 +292,7 @@ export class ParticipantAPI extends DataSource {
     }
 
     async deleteEngagement (id: number, userId: number) {
-        return await deleteEntity(this.connection, Engagement, 'e', id, userId);
+        return await DBUtils.deleteEntity(this.connection, Engagement, 'e', id, userId);
     }
 
     async createEngagementType (engagementType: any) {
@@ -334,6 +334,6 @@ export class ParticipantAPI extends DataSource {
     }
 
     async deleteEngagementType (id: number, userId: number) {
-        return await deleteEntity(this.connection, EngagementType, 'et', id, userId);
+        return await DBUtils.deleteEntity(this.connection, EngagementType, 'et', id, userId);
     }
 }

src/datasources/db/providerAPI.ts

@@ -24,7 +24,7 @@ import { Organisation } from '../../model/Organisation';
 import { UserInputError } from 'apollo-server-express';
 import { CargoBike } from '../../model/CargoBike';
 import { LendingStation } from '../../model/LendingStation';
-import { ActionLogger, deleteEntity, getAllEntity, LockUtils } from './utils';
+import { ActionLogger, DBUtils, LockUtils } from './utils';
 import { GraphQLError } from 'graphql';
 
 export class ProviderAPI extends DataSource {
@@ -43,7 +43,7 @@ export class ProviderAPI extends DataSource {
     }
 
     async provider (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, Provider, 'p', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, Provider, 'p', offset, limit);
     }
 
     async providerByOrganisationId (id: number) {
@@ -71,7 +71,7 @@ export class ProviderAPI extends DataSource {
     }
 
     async organisations (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, Organisation, 'o', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, Organisation, 'o', offset, limit);
     }
 
     async organisationById (id: number) {
@@ -170,7 +170,7 @@ export class ProviderAPI extends DataSource {
     }
 
     async deleteProvider (id: number, userId: number) {
-        return await deleteEntity(this.connection, Provider, 'p', id, userId);
+        return await DBUtils.deleteEntity(this.connection, Provider, 'p', id, userId);
     }
 
     async createOrganisation (organisation: any) {
@@ -213,6 +213,6 @@ export class ProviderAPI extends DataSource {
     }
 
     async deleteOrganisation (id: number, userId: number) {
-        return await deleteEntity(this.connection, Organisation, 'o', id, userId);
+        return await DBUtils.deleteEntity(this.connection, Organisation, 'o', id, userId);
     }
 }

src/datasources/db/utils.ts

@@ -36,21 +36,38 @@ export function genDateRange (struct: any) {
 }
 
 /**
- * Can be used in resolvers to specify if entry is locked by other user.
+ * Can be used in resolvers to specify, if entry is locked by other user.
  * Returns true if locked by other user.
  * @param parent
- * @param dataSources
+ * @param req
- * @param req user request
  */
 export function isLocked (parent: any, { req }: { req: any }) {
     return req.userId !== parent.lockedBy && new Date() <= new Date(parent.lockedUntil);
 }
 
+/**
+ * Can be used in resolvers to specify, if entry is locked by the current user.
+ * @param parent
+ * @param req
+ */
 export function isLockedByMe (parent: any, { req }: { req: any }) {
     return req.userId === parent.lockedBy && new Date() <= new Date(parent.lockedUntil);
 }
 
-export async function deleteEntity (connection: Connection, target: ObjectType<Lockable>, alias: string, id: number, userId: number): Promise<Boolean> {
+/**
+ * Some utility functions for the database
+ */
+export class DBUtils {
+    /**
+     * Delete any instance of an entity that implements the Lockable interface.
+     * It must implement the interface, so it can be be ensured, that the instance is not locked by another user.
+     * @param connection
+     * @param target
+     * @param alias
+     * @param id
+     * @param userId
+     */
+    static async deleteEntity (connection: Connection, target: ObjectType<Lockable>, alias: string, id: number, userId: number): Promise<Boolean> {
         return await connection.transaction(async (entityManger: EntityManager) => {
             if (await LockUtils.isLocked(entityManger, target, alias, id, userId)) {
                 throw new UserInputError('Attempting to delete locked resource');
@@ -62,9 +79,18 @@ export async function deleteEntity (connection: Connection, target: ObjectType<L
                 .where('id = :id', { id: id })
                 .execute().then(value => value.affected === 1);
         });
-}
+    }
 
-export async function getAllEntity (connection: Connection, target: ObjectType<any>, alias: string, offset?: number, limit?: number) {
+    /**
+     * Return all instances of the given entity called target.
+     * When offset or limit is not specified, both values are ignored.
+     * @param connection
+     * @param target
+     * @param alias
+     * @param offset
+     * @param limit
+     */
+    static async getAllEntity (connection: Connection, target: ObjectType<any>, alias: string, offset?: number, limit?: number) {
         if (offset === null || limit === null) {
             return await connection.getRepository(target)
                 .createQueryBuilder(alias)
@@ -78,10 +104,25 @@ export async function getAllEntity (connection: Connection, target: ObjectType<a
                 .take(limit)
                 .getMany();
         }
+    }
 }
 
+/**
+ * Some static functions for the locking feature.
+ */
 export class LockUtils {
-    static async findById (connection: Connection, target: ObjectType<Lockable>, alias: string, id: number): Promise<Lockable> {
+    /**
+     * A helper function to find an instance of any entity that implements Lockable.
+     * It will throw an error, if nothing is found.
+     * Using this function only makes sense to use in the context of locking because there is no point in locking
+     * an instance that does not exist.
+     * @param connection
+     * @param target
+     * @param alias
+     * @param id
+     * @private
+     */
+    private static async findById (connection: Connection, target: ObjectType<Lockable>, alias: string, id: number): Promise<Lockable> {
         return await connection.getRepository(target)
             .createQueryBuilder(alias)
             .select()
@@ -91,6 +132,17 @@ export class LockUtils {
             });
     }
 
+    /**
+     * Lock an instance of an entity target that implements the Lockable interface and return that instance.
+     * If lock could not be set, it will still return the entity.
+     * If lock was set or not can be obtained by the field isLockedByMe in the graphql interface,
+     * or the the fields lockedBy and lockedUntil in the database.
+     * @param connection
+     * @param target
+     * @param alias
+     * @param id
+     * @param userId
+     */
     static async lockEntity (connection: Connection, target: ObjectType<Lockable>, alias: string, id: number, userId: number): Promise<Lockable> {
         const lock = await connection.getRepository(target)
             .createQueryBuilder(alias)
@@ -119,6 +171,17 @@ export class LockUtils {
         return await this.findById(connection, target, alias, id);
     }
 
+    /**
+     * Unlock an instance of an entity target that implements the Lockable interface and return that instance.
+     * If lock could not be unset, it will still return the entity.
+     * If lock was set or not can be obtained by the field isLockedByMe in the graphql interface,
+     * or the the fields lockedBy and lockedUntil in the database.
+     * @param connection
+     * @param target
+     * @param alias
+     * @param id
+     * @param userId
+     */
     static async unlockEntity (connection: Connection, target: ObjectType<Lockable>, alias: string, id: number, userId: number): Promise<Lockable> {
         await connection.getRepository(target)
             .createQueryBuilder(alias)
@@ -161,7 +224,18 @@ export class LockUtils {
     }
 }
 
+/**
+ * Some utility function for the logging features.
+ */
 export class ActionLogger {
+    /**
+     * Create array of strings, that can be used to select them form the database.
+     * If you want to avoid logging all old values, for an update, but only the ones that are updated,
+     * use this function. If updates are null, ['*'] will be returned. Use this for delete actions.
+     * @param updates
+     * @param alias
+     * @private
+     */
     private static buildSelect (updates: any, alias: string) : string[] {
         // this hacky shit makes it possible to select subfields like the address or insurance data. Only one layer at the moment
         if (updates === null) {
@@ -181,6 +255,16 @@ export class ActionLogger {
         return ret;
     }
 
+    /**
+     * Insert an entry in the log. The log ist just another entity in the database.
+     * You can only use this in a transaction. So you have to pass an entity manager.
+     * @param em
+     * @param target
+     * @param alias
+     * @param updates
+     * @param userId
+     * @param action
+     */
     static async log (em: EntityManager, target: ObjectType<any>, alias: string, updates: any, userId: number, action: Actions = Actions.UPDATE) {
         const oldValues = await em.getRepository(target).createQueryBuilder(alias)
             .select(this.buildSelect(updates, alias))

src/datasources/db/workshopAPI.ts

@@ -21,7 +21,7 @@ import { DataSource } from 'apollo-datasource';
 import { Connection, EntityManager, getConnection } from 'typeorm';
 import { WorkshopType } from '../../model/WorkshopType';
 import { Workshop } from '../../model/Workshop';
-import { ActionLogger, deleteEntity, getAllEntity, LockUtils } from './utils';
+import { ActionLogger, DBUtils, LockUtils } from './utils';
 import { UserInputError } from 'apollo-server-express';
 import { GraphQLError } from 'graphql';
 import { Participant } from '../../model/Participant';
@@ -73,7 +73,7 @@ export class WorkshopAPI extends DataSource {
     }
 
     async deleteWorkshop (id: number, userId: number) {
-        return await deleteEntity(this.connection, Workshop, 'w', id, userId);
+        return await DBUtils.deleteEntity(this.connection, Workshop, 'w', id, userId);
     }
 
     async createWorkshopType (workshopType: any) {
@@ -115,7 +115,7 @@ export class WorkshopAPI extends DataSource {
     }
 
     async deleteWorkshopType (id: number, userId: number) {
-        return await deleteEntity(this.connection, WorkshopType, 'wt', id, userId);
+        return await DBUtils.deleteEntity(this.connection, WorkshopType, 'wt', id, userId);
     }
 
     async workshopTypeById (id: number) {
@@ -127,7 +127,7 @@ export class WorkshopAPI extends DataSource {
     }
 
     async workshopTypes (offset?: number, limit?: number) {
-        return getAllEntity(this.connection, WorkshopType, 'wt', offset, limit);
+        return DBUtils.getAllEntity(this.connection, WorkshopType, 'wt', offset, limit);
     }
 
     async workshopById (id: number) {
@@ -144,7 +144,7 @@ export class WorkshopAPI extends DataSource {
      * @param limit
      */
     async workshops (offset?: number, limit?: number) {
-        return await getAllEntity(this.connection, Workshop, 'w', offset, limit);
+        return await DBUtils.getAllEntity(this.connection, Workshop, 'w', offset, limit);
     }
 
     async trainer1ByWorkshopId (id: number) {