IConnectionProviderFactory Interface

Provides methods for creating a provider to restore a data connection on deserializing a report.

Namespace: DevExpress.DataAccess.Web

Assembly: DevExpress.DataAccess.v22.1.dll

NuGet Package: DevExpress.DataAccess

Declaration

C#

public interface IConnectionProviderFactory

VB.NET

Public Interface IConnectionProviderFactory

Remarks

The following code implements the IConnectionProviderFactory and IConnectionProviderService services that translate a connection name (serialized with the report) to a data connection.

CustomSqlDataConnectionProviderFactory.cs

using System;
using System.Collections.Generic;
using System.Linq;
using DevExpress.Data.Entity;
using DevExpress.DataAccess.ConnectionParameters;
using DevExpress.DataAccess.Native;
using DevExpress.DataAccess.Sql;
using DevExpress.DataAccess.Web;
using DevExpress.DataAccess.Wizard.Services;
using AspNetCoreSample.Data;
// ...
    public class CustomSqlDataConnectionProviderFactory : IConnectionProviderFactory {
        private readonly ReportDbContext reportDbContext;

        public CustomSqlDataConnectionProviderFactory(ReportDbContext reportDbContext) {
            this.reportDbContext = reportDbContext;
        }

        public IConnectionProviderService Create() {
            return new CustomSqlConnectionProviderService(reportDbContext.SqlDataConnections.ToList());
        }
    }

    public class CustomSqlConnectionProviderService : IConnectionProviderService {
        readonly IEnumerable<DataConnection> sqlDataConnections;

        public CustomSqlConnectionProviderService(IEnumerable<DataConnection> sqlDataConnections) {
            this.sqlDataConnections = sqlDataConnections;
        }
        public SqlDataConnection LoadConnection(string connectionName) {
            var sqlDataConnectionData = sqlDataConnections.FirstOrDefault(x => x.Name == connectionName);
            if(sqlDataConnectionData == null)
                throw new InvalidOperationException();

            var connectionStringInfo = new ConnectionStringInfo { RunTimeConnectionString = sqlDataConnectionData.ConnectionString, ProviderName = "SQLite" };
            if(string.IsNullOrEmpty(sqlDataConnectionData.ConnectionString)
                || !AppConfigHelper.TryCreateSqlConnectionParameters(connectionStringInfo, out DataConnectionParametersBase connectionParameters)
                || connectionParameters == null) {
                throw new KeyNotFoundException($"Connection string '{connectionName}' not found.");
            }
            return new SqlDataConnection(connectionName, connectionParameters);
        }
    }

The ReportDbContext class contains connection strings:

ReportDbContext.cs

using System.Linq;
using Microsoft.EntityFrameworkCore;
// ...
    public class SqlDataConnectionDescription : DataConnection { }
    public class JsonDataConnectionDescription : DataConnection { }
    public abstract class DataConnection {
        public int Id { get; set; }
        public string Name { get; set; }
        public string DisplayName { get; set; }
        public string ConnectionString { get; set; }
    }
    // ...
    public class ReportDbContext : DbContext {
        public DbSet<JsonDataConnectionDescription> JsonDataConnections { get; set; }
        public DbSet<SqlDataConnectionDescription> SqlDataConnections { get; set; }
        // ...
        public ReportDbContext(DbContextOptions<ReportDbContext> options) : base(options) {
        }
        public void InitializeDatabase() {
            Database.EnsureCreated();

            var nwindJsonDataConnectionName = "NWindProductsJson";
            if(!JsonDataConnections.Any(x => x.Name == nwindJsonDataConnectionName)) {
                var newData = new JsonDataConnectionDescription {
                    Name = nwindJsonDataConnectionName,
                    DisplayName = "Northwind Products (JSON)",
                    ConnectionString = "Uri=Data/nwind.json"
                };
                JsonDataConnections.Add(newData);
            }


            var nwindSqlDataConnectionName = "NWindConnectionString";
            if(!SqlDataConnections.Any(x => x.Name == nwindSqlDataConnectionName)) {
                var newData = new SqlDataConnectionDescription {
                    Name = nwindSqlDataConnectionName,
                    DisplayName = "Northwind Data Connection",
                    ConnectionString = "XpoProvider=SQLite;Data Source=|DataDirectory|/Data/nwind.db"
                };
                SqlDataConnections.Add(newData);
            }

            var reportsDataConnectionName = "ReportsDataSqlite";
            if(!SqlDataConnections.Any(x => x.Name == reportsDataConnectionName)) {
                var newData = new SqlDataConnectionDescription {
                    Name = reportsDataConnectionName,
                    DisplayName = "Reports Data (Demo)",
                    ConnectionString = "XpoProvider=SQLite;Data Source=|DataDirectory|/Data/reportsData.db"
                };
                SqlDataConnections.Add(newData);
            }
            SaveChanges();
        }
    }

See the following help topic for a working example of an application created from a DevExpress template: Create an ASP.NET Core Application with a Report Designer.