public static DbContextEntitiesResult Error(string error)
{
DbContextEntitiesResult result = new DbContextEntitiesResult();
result.Errors.Add(error);
return(result);
}
public DbContextEntitiesResult GetAll(HttpContext httpContext, string contextName, DbContextEntityInfo entityInfo, Dictionary <string, string> where, int?page)
{
DbContextEntitiesResult results = new DbContextEntitiesResult();
results.Fields = entityInfo.Fields;
try
{
Type dbContextType = GetDbContextTypes().FirstOrDefault(y => y.Name == contextName);
DbContext dbContext = httpContext?.RequestServices?.GetService(dbContextType) as DbContext;
if (dbContext == null)
{
return(DbContextEntitiesResult.Error("Cannot find DbContext: " + contextName));
}
object dbSet = Reflector.InvokeGenericMethod(dbContext, "Set", new[] { entityInfo.ClrType });
ParameterExpression x = Expression.Parameter(entityInfo.ClrType, "x");
BinaryExpression lastOperation = null;
foreach (var whereCondition in where)
{
var fieldInfo = entityInfo.Fields.FirstOrDefault(f => f.Name == whereCondition.Key);
var operation = Expression.Equal(
Expression.Call(typeof(EF), nameof(EF.Property), new[] { fieldInfo.ClrType }, x, Expression.Constant(whereCondition.Key)),
Expression.Constant(Binder.ConvertToType(whereCondition.Value, fieldInfo.ClrType), fieldInfo.ClrType));
if (lastOperation == null)
{
lastOperation = operation;
}
else
{
lastOperation = Expression.And(lastOperation, operation);
}
}
if (lastOperation != null)
{
Type delegateType = typeof(Func <,>).MakeGenericType(entityInfo.ClrType, typeof(bool));
LambdaExpression predicate = Expression.Lambda(delegateType, lastOperation, x);
var whereMethod = typeof(System.Linq.Queryable).GetMethods(BindingFlags.Static | BindingFlags.Public)
.FirstOrDefault(m => m.Name == "Where" && m.GetParameters().Count() == 2);
MethodInfo genericWhereMethod = whereMethod.MakeGenericMethod(new[] { entityInfo.ClrType });
dbSet = genericWhereMethod.Invoke(null, new object[] { dbSet, predicate });
}
int take = 200;
int skip = (page.GetValueOrDefault(1) - 1) * 200;
var skipMethod = typeof(System.Linq.Enumerable).GetMethods(BindingFlags.Static | BindingFlags.Public)
.FirstOrDefault(m => m.Name == "Skip" && m.GetParameters().Count() == 2);
MethodInfo genericSkipMethod = skipMethod.MakeGenericMethod(new[] { entityInfo.ClrType });
dbSet = genericSkipMethod.Invoke(null, new object[] { dbSet, skip });
//dbSet = typeof(System.Linq.Enumerable).InvokeStaticGenericMethod("Skip", new[] { entityInfo.ClrType }, dbSet, take);
var takeMethod = typeof(System.Linq.Enumerable).GetMethods(BindingFlags.Static | BindingFlags.Public)
.FirstOrDefault(m => m.Name == "Take" && m.GetParameters().Count() == 2);
MethodInfo genericTakeMethod = takeMethod.MakeGenericMethod(new[] { entityInfo.ClrType });
dbSet = genericTakeMethod.Invoke(null, new object[] { dbSet, take });
//dbSet = typeof(System.Linq.Enumerable).InvokeStaticGenericMethod("Take", new[] { entityInfo.ClrType }, dbSet, take);
var toListMethod = typeof(System.Linq.Enumerable).GetMethods(BindingFlags.Static | BindingFlags.Public)
.FirstOrDefault(m => m.Name == "ToList" && m.GetParameters().Count() == 1);
MethodInfo genericToListMethod = toListMethod.MakeGenericMethod(new[] { entityInfo.ClrType });
dbSet = genericToListMethod.Invoke(null, new object[] { dbSet });
foreach (var entity in dbSet as System.Collections.IEnumerable)
{
var entityEntry = dbContext.Entry(entity);
object[] row = new object[entityInfo.Fields.Count];
for (int i = 0; i < entityInfo.Fields.Count; i++)
{
row[i] = entityEntry.Property(entityInfo.Fields[i].Name).CurrentValue;
}
results.Rows.Add(row);
}
return(results);
}
catch (Exception ex)
{
results.Errors.Add(ex.GetAllMessages());
}
return(results);
}