Event Fame search using AFSearch for a template over a subset of elements

Hi Lonnie,

I don't have an example to match exactly what you want to do, but I do have an example illustrating nested tokens using the new AFAttributeSearch.  I am sure you will be able to apply to your situation.  Instead of searching on 2 templates (1 for EF and 1 for elements), I will be searching on 2 names (1 for attribute and 1 for element).  The main thing is notice the syntax.  All 3 examples do the same thing but do it differently.  The first uses AFSearchToken, the second uses a plain query string, and the third uses an Interpolated string.

// Goal is to find attributes named "Feed Rate" on any elements named "Boiler*"

// Finds 1 attribute per element, using nested query tokens.
// New to AF 2.9.5: AFSearchToken.Tokens property.
public static void FindAttributeDemo21(AFElement root)
{
    // Set up the nested element search tokens
    var nestedTokens = new List<AFSearchToken>();
    nestedTokens.Add(new AFSearchToken(AFSearchFilter.Name, "Boiler*"));


    // Set up the outer attribute search tokens, which use the nested tokens
    var tokens = new List<AFSearchToken>();
    // The Element uses the nested token(s)
    tokens.Add(new AFSearchToken(AFSearchFilter.Element, AFSearchOperator.Equal, null, nestedTokens));
    // The Attribute uses a simple Name search
    // NOTE 'Feed Rate' is the attribute name, whereas '|Feed Rate' is the path (relative to the element).
    tokens.Add(new AFSearchToken(AFSearchFilter.Name, "Feed Rate"));

    using (var search = new AFAttributeSearch(root.Database, "attr demo 2.1", tokens))
    {
        search.CacheTimeout = TimeSpan.FromMinutes(10);
        foreach (var item in search.FindAttributes())
        {
            // do something
        }
    }
}

// Same as above but using nested { } in query strings.
public static void FindAttributeDemo22(AFElement root)
{
    // NOTE how element has nested { }. 
    var query = "Element:{Name:'Boiler*'} Name:'Feed Rate'";

    using (var search = new AFAttributeSearch(root.Database, "attr demo 2.2", query))
    {
        search.CacheTimeout = TimeSpan.FromMinutes(10);
        foreach (var item in search.FindAttributes())
        {
            // do something
        }
    }
}

// Same as above but using nested { } in Interpolated query strings.
public static void FindAttributeDemo23(AFElement root)
{
    string elemName = "Boiler*";
    string attrName = "Feed Rate";

    // This gives a compile error with an Interpolated string
    //var query = $"Element:{Name:'{elemName}'} Name:'{attrName}'";

    // Escape the { and } around literal braces with {{ and }} 
    var query = $"Element:{{Name:'{elemName}'}} Name:'{attrName}'";

    using (var search = new AFAttributeSearch(root.Database, "attr demo 2.3", query))
    {
        search.CacheTimeout = TimeSpan.FromMinutes(10);
        foreach (var item in search.FindAttributes())
        {
            // do something
        }
    }
}

To help round out the discussion, here are some links:

What's New AF 2017 R2 (AF SDK 2.9.5)

Search Overview - strongly suggest you BOOKMARK this link

AFSearchToken constructor with nested tokens

It was easy to miss since it was released on December 27 during busy holiday season.

Cool, Lonnie.  I'd love to know the results later.  You can shoot me a private message or post here.  If you don't, I will HUNT YOU DOWN AT PI WORLD.