Topics

All topics

Development

Use Join queries with dynamic content types
Example

This article contains
NEW TO SITEFINITY?

Overview

When you work with dynamic content type, such as instances of the type Telerik.Sitefinity.DynamicModules.Model.DynamicContent, you may use various LINQ operations. This article demonstrates how to use the Join operation. 
For more information, see the MSDN »  Querable.Join method.

This article uses the terms TInner, TOuter, and TResult with the same meaning as the MSDN article.

Supported cases

Sitefinity CMS supports the following combinations of Join queries with generic types for outer and inner Join arguments:

  • Only TOuter is DynamicContent.
  • Only TInner is DynamicContent.
  • Both TOuter and TInner are DynamicContent.

Requirements

Sitefinity CMS support all of these combinations with some requirements on TResult:

  • You must not use dynamic types directly anywhere.
  • You must return static, non-anonymous, custom result type for TResult.
You extract the required fields values into properties of the resulting custom static type. Using this technique, you avoid using the dynamic types directly.

The examples in this article contain the following:

  • The first example defines the JoinResult class that the other two code samples use.
  • The second example demonstrates how you must use Join queries.
  • The third example demonstrated how you must not use Join queries.

Example: Define the JoinResult class

The following code samples has a DynamicContent type Hotel. It containing the child type Room. To keep the results from the computation, the type JoinResults is introduced:

using System;
using Telerik.Sitefinity.DynamicModules.Model;
namespace SitefinityWebApp.Examples
{
public class JoinResult
{
public string HotelTitle { get; set; }
public Guid RelatedDataId { get; internal set; }
public string HotelRoomTitle { get; internal set; }
public decimal HotelRating { get; internal set; }
public decimal RoomSize { get; internal set; }
public DynamicContent Hotel { get; internal set; }
}
}
view raw JoinResults.cs hosted with ❤ by GitHub

Example: Recommended usage

In the following code sample, you can find examples of how you must use the Join queries in Sitefinity CMS. The code sample demonstrates the following:

  • How to use static types as return results for LINQ queries.
    Instead of using dynamic types directly anywhere, return static, non-anonymous custom type for TResult, and extract the required fields values into properties of TResult.
  • How to work with Lstring values on DynamicContent types.
  • How to get values for specific culture when your site uses multilingual mode.
using System;
using System.Globalization;
using System.Linq;
using System.Web.UI;
using Telerik.Sitefinity.Data.ContentLinks;
using Telerik.Sitefinity.Data.Linq.Dynamic;
using Telerik.Sitefinity.Descriptors;
using Telerik.Sitefinity.DynamicModules;
using Telerik.Sitefinity.DynamicModules.Model;
using Telerik.Sitefinity.GenericContent.Model;
using Telerik.Sitefinity.Localization;
using Telerik.Sitefinity.Model;
using Telerik.Sitefinity.Model.ContentLinks;
namespace SitefinityWebApp.Examples
{
public partial class DynamicLINQJoins_RecommendedUsage : Page
{
private Type hotelType = Telerik.Sitefinity.Utilities.TypeConverters.TypeResolutionService.ResolveType("Telerik.Sitefinity.DynamicTypes.Model.Hotels.Hotel");
private Type hotelRoomType = Telerik.Sitefinity.Utilities.TypeConverters.TypeResolutionService.ResolveType("Telerik.Sitefinity.DynamicTypes.Model.Hotels.Room");
private DynamicModuleManager modManager = DynamicModuleManager.GetManager();
private IQueryable<DynamicContent> hotels;
private IQueryable<DynamicContent> hotelRooms;
private IQueryable<ContentLink> relatedData;
public DynamicLINQJoins_RecommendedUsage()
{
this.hotels = this.modManager.GetDataItems(this.hotelType)
.Where("Status == Master");
this.hotelRooms = this.modManager.GetDataItems(this.hotelRoomType)
.Where(x => x.Status == ContentLifecycleStatus.Master);
// Static type - ContentLink
this.relatedData = ContentLinksManager.GetManager().GetContentLinks();
}
protected void RecommendedUsage()
{
// Return static custom type (not anonymous) for TResult.
// Do not use the dynamic types directly anywhere
// Extract the necessary fields values into properties of TResult
{
var outerDynamicInnerStatic = Queryable.Join(this.hotels, this.relatedData, h => h.Id, rd => rd.ParentItemId,
(h, i) => new JoinResult { HotelRating = h.GetValue<decimal?>("Stars").Value, RelatedDataId = i.Id })
.Where(x => x.HotelRating == 3).ToList();
var outerStaticInnerDynamic = Queryable.Join(this.relatedData, this.hotels, rd => rd.ParentItemId, h => h.Id,
(rd, h) => new JoinResult { HotelRating = h.GetValue<decimal?>("Stars").Value, RelatedDataId = rd.ChildItemId })
.Where(x => x.HotelRating == 3).ToList();
var outerDynamicInnerDynamic = Queryable.Join(this.hotelRooms, this.hotels, hr => hr.SystemParentId, h => h.Id,
(hr, h) => new JoinResult { HotelRating = h.GetValue<decimal?>("Stars").Value, RoomSize = hr.GetValue<decimal?>("Size").Value })
.Where(x => x.HotelRating == 3).ToList();
}
// When only TOuter is DynamicContent, in Telerik.Sitefinity.Model, specify the Lstring as generic argument for the GetValue extension method.
// When only TInner is DynamicContent or both TOuter and TInner are DynamicContent, specify the Lstring as generic argument
{
var outerDynamicInnerStatic = Queryable.Join(this.hotels, this.relatedData, h => h.Id, rd => rd.ParentItemId,
(h, i) => new JoinResult { HotelTitle = h.GetValue<string>("Title"), RelatedDataId = i.Id })
.Where(x => x.HotelTitle == "Hotel_2");
var outerStaticInnerDynamic = Queryable.Join(this.relatedData, this.hotels, rd => rd.ParentItemId, h => h.Id,
(rd, h) => new JoinResult { HotelTitle = h.GetValue<Lstring>("Title"), RelatedDataId = rd.ChildItemId })
.Where(x => x.HotelTitle == "Hotel_2");
var outerDynamicInnerDynamic = Queryable.Join(this.hotelRooms, this.hotels, hr => hr.SystemParentId, h => h.Id,
(hr, h) => new JoinResult { HotelTitle = h.GetValue<Lstring>("Title"), HotelRoomTitle = hr.GetValue<Lstring>("Title") })
.Where(x => x.HotelTitle == "Hotel_2");
}
// In multilingual mode, get the specific culture values for Lstring properties of Dynamic Types in the following way:
// When only TOuter is DynamicContent, you must use the special field name for the culture that you want
// When only TInner is DynamicContent or both TOuter and TInner are DynamicContent, you must use the CultureRegion when executing the queries
{
string fieldNameForCulture = LstringPropertyDescriptor.GetFieldNameForCulture("Title", CultureInfo.GetCultureInfo("bg"));
var outerDynamicInnerStatic = Queryable.Join(this.hotels, this.relatedData, h => h.Id, rd => rd.ParentItemId,
(h, i) => new JoinResult { HotelTitle = h.GetValue<string>(fieldNameForCulture), RelatedDataId = i.Id })
.Where(x => x.HotelTitle == "Хотел_2");
using (new CultureRegion("bg"))
{
var outerStaticInnerDynamic = Queryable.Join(this.relatedData, this.hotels, rd => rd.ParentItemId, h => h.Id,
(rd, h) => new JoinResult { HotelTitle = h.GetValue<Lstring>("Title"), RelatedDataId = rd.ChildItemId })
.Where(x => x.HotelTitle == "Хотел_2");
var outerDynamicInnerDynamic = Queryable.Join(this.hotelRooms, this.hotels, hr => hr.SystemParentId, h => h.Id,
(hr, h) => new JoinResult { HotelTitle = h.GetValue<Lstring>("Title"), HotelRoomTitle = hr.GetValue<Lstring>("Title") })
.Where(x => x.HotelTitle == "Хотел_2");
}
}
}
}
}
view raw DynamicLINQJoins_RecommendedUsage.cs hosted with ❤ by GitHub

Example: Limitations

The following code sample demonstrates edge cases and limitations that, when used, will throw exceptions:

TOuter is DynamicContent type

In this case:

  • You cannot return dynamic type results as properties of objects. However, you can return dynamic type results directly (TResult is DynamicContent). In this case, you must use extension methods in Telerik.Sitefinity.Data.Linq.Dynamic to query them afterwards.
  • Complex type results are supported in this case, if dynamic type results are not used. However, you can extract properties of dynamic types and assign them to other properties on a new static type.
  • It is not possible to return anonymous object types.
  • It is not possible to return DynamicContent types on properties.

TInner or both TOuter and TInner are DynamicContent types

In these cases:

  • You can return anonymous types, but you cannot return dynamic types directly. 
    If you want to return dynamic objects in the result, you must wrap them as properties of anonymous return type. 
    Extension methods in Telerik.Sitefinity.Data.Linq.Dynamic do not work after the join. 
    You have to use standard LINQ extension methods in subsequent expressions. These extensions will work, if used in expressions that were passed as parameters to the Join.
  • It is not possible to return dynamic type directly. 
    Instead, wrap the dynamic types in anonymous objects or custom result objects.
using System;
using System.Linq;
using System.Web.UI;
using Telerik.Sitefinity.Data.ContentLinks;
using Telerik.Sitefinity.Data.Linq.Dynamic;
using Telerik.Sitefinity.DynamicModules;
using Telerik.Sitefinity.DynamicModules.Model;
using Telerik.Sitefinity.GenericContent.Model;
using Telerik.Sitefinity.Model;
using Telerik.Sitefinity.Model.ContentLinks;
namespace SitefinityWebApp.Examples
{
public partial class DynamicLINQJoins_EdgeCases : Page
{
private Type hotelType = Telerik.Sitefinity.Utilities.TypeConverters.TypeResolutionService.ResolveType("Telerik.Sitefinity.DynamicTypes.Model.Hotels.Hotel");
private Type hotelRoomType = Telerik.Sitefinity.Utilities.TypeConverters.TypeResolutionService.ResolveType("Telerik.Sitefinity.DynamicTypes.Model.Hotels.Room");
private DynamicModuleManager modManager = DynamicModuleManager.GetManager();
private IQueryable<DynamicContent> hotels;
private IQueryable<DynamicContent> hotelRooms;
private IQueryable<ContentLink> relatedData;
public DynamicLINQJoins_EdgeCases()
{
this.hotels = this.modManager.GetDataItems(this.hotelType)
.Where("Status == Master");
this.hotelRooms = this.modManager.GetDataItems(this.hotelRoomType)
.Where(x => x.Status == ContentLifecycleStatus.Master);
// Static type - ContentLink
this.relatedData = ContentLinksManager.GetManager().GetContentLinks();
}
// CASE 1: When ONLY TOuter is DynamicContent
protected void UseCasesPeculiarities_TOuterIsDynamicContent()
{
// This approach is backward compatible, but we do not recommend to continue using it
// You cannot return dynamic type results as properties of objects.
// You can return dynamic type results directly (TResult is DynamicContent) and you must use extension methods in
// Telerik.Sitefinity.Data.Linq.Dynamic to query them afterwards.
var dynamicResult = Queryable.Join(this.hotels, this.relatedData, h => h.Id, rd => rd.ParentItemId,
(h, i) => h)
.Where("Title == \"Hotel_2\"");
// Complex type results are supported in this case so long as dynamic type results are not used.
// You can extract properties of dynamic types and assign them to other properties on a new static type.
var nonDynamicResult = Queryable.Join(this.hotels, this.relatedData, h => h.Id, rd => rd.ParentItemId,
(h, i) => new JoinResult { HotelTitle = h.GetValue<string>("Title"), RelatedDataId = i.Id })
.Where(x => x.HotelTitle == "Hotel_2");
// It is not possible to return anonymous object types - attempting to do so throws an exception.
try
{
var dynamicOuterStaticInnerReturnsAnonymous = Queryable.Join(this.hotels, this.relatedData, h => h.Id, rd => rd.ParentItemId,
(h, i) => new { Hotel = h })
.ToList();
}
catch (Exception)
{
// Expected, because this case is not supported
}
// It is not possible to return DynamicContent types on properties and attempting to do so throws an exception on the Where clause
try
{
var dynamicOuterStaticInnerReturnsAnonymous = Queryable.Join(this.hotels, this.relatedData, h => h.Id, rd => rd.ParentItemId,
(h, i) => new JoinResult { Hotel = h })
.Where(x => x.Hotel.GetValue<string>("Title") == "Hotel_2")
.ToList();
}
catch (Exception)
{
// Expected, because this case is not supported
}
}
// When only TInner is DynamicContent or
// When both TOuter and TInner are DynamicContent
protected void UseCasesPeculiarities_TInnerIsDynamicContentOrBothAreDynamicContent()
{
// This always throws an exception when calling the join.
// You can return anonymous types, but you cannot return dynamic types directly.
// If you want to return dynamic objects in the result, you must wrap them as properties of anonymous return type.
// Extensions in Telerik.Sitefinity.Data.Linq.Dynamic will not be working after the join, and
// you must use standard Linq extension methods in subsequent expressions.
// Extensions in Telerik.Sitefinity.Data.Linq.Dynamic are working, if used in expressions that were passed as parameters to the Join method.
this.hotels = this.modManager.GetDataItems(this.hotelType)
.Where("Status == Master");
// This works, because it is before the Jopin method call.
var outerStaticInnerDynamicAnonymousReturnType = Queryable.Join(this.relatedData, this.hotels, rd => rd.ParentItemId, h => h.Id, (rd, h) => new { Hotel = h, ImageId = rd.ChildItemId });
var res5 = outerStaticInnerDynamicAnonymousReturnType
//.Where("Hotel.Title == \"Hotel_1\""); // does not work,
// because the calls to Telerik.Sitefinity.Data.Linq.Dynamic extension methods is after the Join method
.Where(x => x.Hotel.GetValue<Lstring>("Title") == "Hotel_2");
var res6 = res5.ToList();
// The same rules apply when TOuter and TInner are both dynamic types
var outerDynamicInnerStaticAnonymousReturnType = Queryable.Join(this.hotels, this.hotelRooms, x => x.OriginalContentId, x => x.SystemParentId, (x, y) => new
{
Hotel = x,
Room = y,
RoomSize = y.GetValue<decimal?>("Size").Value,
HotelStars = x.GetValue<decimal?>("Stars").Value
});
var res7 = outerDynamicInnerStaticAnonymousReturnType.Where(x => x.RoomSize == 1).OrderBy(x => x.Hotel.GetValue<decimal?>("Stars").Value);
var res8 = res7.ToList();
try
{
// It is not possible to return dynamic type directly. This will throw an exception on the Where clause.
// Instead, you must wrap the dynamic types in anonymous objects or custom result objects.
var dynamicReturnType = Queryable.Join(this.hotels, this.hotelRooms, x => x.OriginalContentId, x => x.SystemParentId, (x, y) => y);
var res9 = dynamicReturnType.Where(x => x.GetValue<decimal?>("Size").Value == 1);
var res10 = res9.ToList();
}
catch (Exception)
{ }
}
}
}
view raw DynamicLINQJoins_EdgeCases.cs hosted with ❤ by GitHub

Want to learn more?

Increase your Sitefinity skills by signing up for our free trainings. Get Sitefinity-certified at Progress Education Community to boost your credentials.

Get started with Integration Hub | Sitefinity Cloud | Sitefinity SaaS

This free lesson teaches administrators, marketers, and other business professionals how to use the Integration hub service to create automated workflows between Sitefinity and other business systems.

Web Security for Sitefinity Administrators

This free lesson teaches administrators the basics about protecting yor Sitefinity instance and its sites from external threats. Configure HTTPS, SSL, allow lists for trusted sites, and cookie security, among others.

Foundations of Sitefinity ASP.NET Core Development

The free on-demand video course teaches developers how to use Sitefinity .NET Core and leverage its decoupled architecture and new way of coding against the platform.

Was this article helpful?