MSDN Magazine - July 2008 - (Page 65)

Figure 9 Adding a Schema listingSchemaEntity.Kind = "ListingSchema"; listingSchemaEntity.Properties = new Dictionary (); listingSchemaEntity.Properties["ListingID"] = m_ListingID; listingSchemaEntity.Properties["ListingName"] = m_ListingName; int propCount = 0; bool required = false; foreach (DataGridViewRow row in dataGridView1.Rows) { if (row.IsNewRow) continue; propCount++; listingSchemaEntity.Properties[string.Format ("Property{0}Name",propCount)] = row.Cells["colFieldName"].Value.ToString(); listingSchemaEntity.Properties[string.Format ("Property{0}DataType", propCount)] = row.Cells["colDataType"].Value.ToString(); if (row.Cells["colRequired"].Value == null) { required = false; } else { required = Convert.ToBoolean(row.Cells ["colRequired"].Value.ToString()); } listingSchemaEntity.Properties[string.Format } ("Property{0}Required", propCount)] = required; if (propCount > 0) { using (SSDSClient.SitkaSoapServiceClient ssdsProxy = new SSDSClient.SitkaSoapServiceClient()) { //Set username and password for the service //Set service scope to the main contoso classifieds //authority. Point it to the categories container //If this entity doesn't exist, create it if (listingSchemaID == "" || listingSchemaID == null) { ssdsProxy.Create(serviceScope, listingSchemaEntity); } //Otherwise update it else { serviceScope.EntityId = listingSchemaID; ssdsProxy.Update(serviceScope, listingSchemaEntity); } } } MessageBox.Show("Custom Schema Saved", "Custom Schema Saved", MessageBoxButtons.OK, MessageBoxIcon.Information); this.Hide(); this to store different entity types within the same container and also to query for entities of a specific type or, in this case, Kind. While there is no schema contract associated with Kind, it is easy to use this mechanism to group similar data. Now I will add a new entity of Kind ListingSchema to the Categories container. The dialog for adding a listing schema is quite simple, as shown in Figure 8. It allows the administrator to define additional fields that are associated with a listing and to identify certain fields as being required. I will go into more detail about this later when I show you how to implement the actual Web site. The process used to add the ListingSchema entity is the same one you’ve already seen, but this time using a different entity (Kind). The code for the adding the ListingSchema is shown in Figure 9. After adding a listing schema for a For Sale Cars category, notice that the Figure 10 DeleteListingSchema //Retrieve the custom schema entity for this listing string linqQuery = string.Format( @"from e in entities where e.Id == ""{0}"" select e", CategoryID); List entities = ssdsProxy.Query(serviceScope, linqQuery); foreach (SSDSClient.Entity entity in entities) { //If more than 1 flex property on the entity, the //header has listing categories attached to it. if (entity.Properties.Count > 1) { //Calculate the number of Listing Categories int propCount = ((entity.Properties.Count - 1) / 2); for (int x = 1; x < propCount + 1; x++) { //Delete the listing schema for each listing //in this category DeleteListingSchema(entity.Properties["ListingCategoryID" + x.ToString()].ToString()); } } contents of the Categories container include two different entity types, with completely different data in the same container. The last piece of the admin client is to delete a custom listing schema when a listing category is deleted. I previously discussed delet- You can access SSDS via its REST interface as well as its SOAP interface. ing entities and containers, but then I knew the ID of the entity or container I wanted to delete. Deleting a schema means first issuing a LINQ query to retrieve all listing schemas that are attached to the listing categories and deleting them. The query looks like this: string.Format(@"from e in entities where e.Id == ""{0}"" select e", CategoryID); That query will return a list of ListingSchema entities, and all you need to do at this point is delete them. The entire DeleteListingSchema method is shown in Figure 10. At this point the Contoso Classifieds Administration client is complete and I can move on the implementing the Web site using the REST interface of SSDS. The Classifieds Web App } As mentioned earlier, you can access SSDS via its REST interface as well as its SOAP interface (as I did for the Contoso Classifieds Administration client). The concepts and features are the same regardless of the interface you choose, but with REST you will make direct HTTP (or HTTPS) calls. July 2008 65 msdnmagazine.com http://msdnmagazine.com

Table of Contents Feed for the Digital Edition of MSDN Magazine - July 2008

MSDN Magazine - July 2008 Contents Toolbox CLR Inside Out Flex Your Data Data Points Advanced Basics Office Space Cutting Edge Data Services ADO.NET Data and WPF Transactions WCF P2P Test Run Security Briefs Foundations .NET Matters {End Bracket}

MSDN Magazine - July 2008

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