示例#1
0
        public BusinessesVM(IDbContextFactory <BusinessDbContext> dbContextFactory, IDbChangeObserver dbChangeObserver)
        {
            _dbContextFactory = dbContextFactory;

            using var dbContext = _dbContextFactory.CreateDbContext();
            Businesses          = dbContext.Businesses.OrderBy(x => x.Id).ToList();

            this.ObserveList <Business>(nameof(Businesses), dbChangeObserver);
        }
示例#2
0
        public ListenOnlyVM(IDbChangeObserver dbChangeObserver)
        {
            Businesses = new List <Business>();

            _subs = dbChangeObserver.Observe <Business>().Subscribe(e =>
            {
                if (e is DbInsertEvent <Business> )
                {
                    this.AddList(nameof(Businesses), (e as DbInsertEvent <Business>).Row);
                }
                else if (e is DbUpdateEvent <Business> )
                {
                    this.UpdateList(nameof(Businesses), (e as DbUpdateEvent <Business>).NewRow);
                }
                else if (e is DbDeleteEvent <Business> )
                {
                    var key = (e as DbDeleteEvent <Business>).Row.Id;
                    this.RemoveList(nameof(Businesses), key);
                }

                PushUpdates();
            });
        }
示例#3
0
        /// <summary>
        /// Observes database changes on the table associated with a view model's list property.
        /// </summary>
        /// <typeparam name="TTable">Type associated with a database table.</typeparam>
        /// <typeparam name="TList">Type associated with the view model's list.</typeparam>
        /// <param name="baseVM">View model instance.</param>
        /// <param name="listPropName">Property name of the view model's list.</param>
        /// <param name="dbChangeObserver">Db change observer service.</param>
        /// <param name="selector">Selector to transform TTable instance into TList instance.</param>
        public static void ObserveList <TTable, TList>(this BaseVM baseVM, string listPropName, IDbChangeObserver dbChangeObserver, Func <TTable, TList> selector) where TTable : new()
        {
            listPropName = listPropName ?? throw new ArgumentNullException(nameof(listPropName));

            PropertyInfo listProp = baseVM.GetType().GetProperty(listPropName);

            listProp = listProp ?? throw new DotNetifyPostgresException($"Property '{baseVM.GetType().Name}.{listPropName}' was not found.");

            string itemKeyPropName = listProp.GetCustomAttribute <ItemKeyAttribute>()?.ItemKey;

            if (itemKeyPropName == null)
            {
                itemKeyPropName = baseVM.RuntimeProperties.FirstOrDefault(x => x.Name == $"{listPropName}_itemKey")?.Name;
            }

            itemKeyPropName = itemKeyPropName ?? throw new DotNetifyPostgresException($"Property '{baseVM.GetType().Name}.{listPropName}' doesn't define an item key.");

            PropertyInfo itemKeyPropInfo = typeof(TTable).GetProperty(itemKeyPropName);

            bool handleDbChangeEvent(IDbChangeEvent <TTable> dbChangeEvent)
            {
                if (dbChangeEvent is DbInsertEvent <TTable> )
                {
                    baseVM.AddList(listPropName, selector((dbChangeEvent as DbInsertEvent <TTable>).Row));
                }
                else if (dbChangeEvent is DbUpdateEvent <TTable> )
                {
                    baseVM.UpdateList(listPropName, selector((dbChangeEvent as DbUpdateEvent <TTable>).NewRow));
                }
                else if (dbChangeEvent is DbDeleteEvent <TTable> )
                {
                    var key = itemKeyPropInfo.GetValue((dbChangeEvent as DbDeleteEvent <TTable>).Row);
                    baseVM.RemoveList(listPropName, key);
                }
                else
                {
                    return(false);
                }

                baseVM.PushUpdates();
                return(true);
            }

            baseVM.AddInternalProperty <bool>($"{listPropName}_observe").SubscribeTo(dbChangeObserver.Observe <TTable>().Select(handleDbChangeEvent));
        }
示例#4
0
 /// <summary>
 /// Observes database changes on the table associated with a view model's list property.
 /// </summary>
 /// <typeparam name="TTable">Type associated with a database table.</typeparam>
 /// <param name="baseVM">View model instance.</param>
 /// <param name="listPropName">Property name of the view model's list.</param>
 /// <param name="dbChangeObserver">Db change observer service.</param>
 public static void ObserveList <TTable>(this BaseVM baseVM, string listPropName, IDbChangeObserver dbChangeObserver) where TTable : new()
 {
     ObserveList <TTable, TTable>(baseVM, listPropName, dbChangeObserver, _ => _);
 }