Alf Nilsson talks

There are several exciting things with the new Blocks in EPiServer 7 CMS. One of the most convenient things when you need to add a group of data to a page type, for example an image + alternative text or an url + clickable text or maybe a group of SEO data such as title, description and keywords.

Note that this article does not include how Global Blocks are saved. I have only focused on Blocks that are added as Properties on a Content Type.

I have create a sample Page Type TestPage containing 2 sets of the block TestBlock which itself only contains the string Property TestValue. TestBlock1 contains the value “abc” and TestBlock2 contains the value “def”.

When I check the database structure I can find these traces of ContentTypes, Properties and values. I have marked the recurring values to mark how the relations are set between all  tables.

[tblContentType]

[tblPropertyDefinitionType]

Where the column fkContentTypeGUID is null on PropertyDefinitionTypes that are not connected to a ContentType

[tblPropertyDefinition]

Where fkPropertyDefinitionTypeID 7 mean it’s a normal string and strangely 12 is a XhtmlString but I guess it has something to do with rendering. *adding to future blogs list*

[tblContentProperty]

I have created a Page of TestPage. The page have Id 183, it didn’t feel necessary to add that table to this chart but as you can see, the values of TestBlock1 and TestBlock2 have a fkContentID that referers to the PageData it is stored on.

The column ScopeName is a relational path that connects the Name property to the TestBlock Block named TestBlock1.

Find Pages based on this?

The datastructure for Blocks in tblContrentProperty are quite flat. Therefore I can find my Test Page by creating a FindPagesWithCriteria:

IPageCriteriaQueryService repository = ServiceLocator.Current.GetInstance();

PropertyCriteriaCollection criterias = new PropertyCriteriaCollection
{
    new PropertyCriteria
    {
        Condition = CompareCondition.Equal,
        Required = true,
        Name = "TestValue",
        Type = PropertyDataType.String,
        Value = "abc"
    }
};
PageDataCollection result = repository.FindPagesWithCriteria(ContentReference.RootPage, criterias);

FindPagesWithCriteria sends queries to a couple of Stored Procedures in the database and checks among the tables whether the Pages have a Property with the given name and  if the Property value fits the criteria.

And what is the result?

Unfortunately since there is no way to define that I only want to search for a page where TestBlock1 have a TestValue with value “abc”, I will receive ALL pages that have a Property called TestValue with a value of “abc” no matter if they are saved on a block or directly on the page.

This really sounds like a job for EPiServer Find but if you don’t have it installed, FindPagesWithCriteria can be quite good at times except for the disadvantages of many queries to the database and its cumbersome API.

Though the advantages is its stability and being straightforward. Remember to not add too many criterion and try to Cache-smart if you using it

What I can find there is no good way to change the behaviour of FindPagesWithCriteria without copying quite alot of the existing logic or rewriting the existing Stores Procedures.