Is it possible to define ECProperty as enum type?

I'm looking for the same thing. Did you make any headway on this?

Thanks for any input you could share!

-Chris

Jan Šlegr said:

is it possible (and if yes, is there an example available) to define ECProperty as enum type

Hidden in MicroStation CONNECT Update 7 are Pick Lists.  In that Update I don't think that they were intended to be publicly visible.  Perhaps we'll see more in Update 8.

See Krister Surell's post about Picklists and C#.  He obviously spotted something that I missed!

AFAIK all ECProperties (and hence Item Types) are ultimately XML data.  There are structures such as ValueMaps (see the delivered EC Schemas) that could be interpreted as a C#/C++ enum,  but there's no way that I know of to convert a ValueMap to an enum at run-time.

I'm relatively certain the new "pick lists" are only usable with Item Types (created in MicroStation's Item Types dialog), not general ECSchemas. I could be wrong.

However ECSchemas have for years supported custom attributes which behave like enums and are displayed to the user as a pick list in a drop-down when editing property values. For example, to define a "widget size" property with allowable values of Small, Medium, and Large:

<ECProperty propertyName="WidgetSize" typeName="int" displayLabel="Widget Size">
    <ECCustomAttributes>
        <StandardValues xmlns="EditorCustomAttributes.01.00">
            <ValueMap>
                <ValueMap>
                    <Value>0</Value>
                    <DisplayString>Small</DisplayString>
                </ValueMap>
                <ValueMap>
                    <Value>1</Value>
                    <DisplayString>Medium</DisplayString>
                </ValueMap>
                <ValueMap>
                    <Value>2</Value>
                    <DisplayString>Large</DisplayString>
                </ValueMap>
            </ValueMap>
        </StandardValues>
    </ECCustomAttributes>
</ECProperty>

Regards,

Paul

Thanks, Jon Summers. I always appreciate your time and expertise. Unfortunately for me I'm working in SS3 and don't have experience with C#/C++ (yet?), so I'm constrained to find a solution via the XML schema and VBA if necessary.

Thanks, Paul! This gets me 85% of the way there, which is enough for a working solution for my project. What I'm now hacking away at is to define a similar structure to a "ValueMap" which enables me to define their "Value" as a string as opposed to an integer, so that when users enter in a value not predefined, it will not error out with "ECStandardValues TypeConverter cannot convert from System.String". Something more like:

<ECProperty propertyName="WidgetSize" typeName="string" displayLabel="Widget Size">
    <ECCustomAttributes>
        <StandardValuesString xmlns="MyOwnCustomAttributes.01.00">
            <ValueMapString>
                <ValueMapString>
                    <Value>A</Value>
                    <DisplayString>Small</DisplayString>
                </ValueMapString>
                <ValueMapString>
                    <Value>B</Value>
                    <DisplayString>Medium</DisplayString>
                </ValueMapString>
                <ValueMapString>
                    <Value>C</Value>
                    <DisplayString>Large</DisplayString>
                </ValueMapString>
            </ValueMapString>
        </StandardValuesString>
    </ECCustomAttributes>
</ECProperty>

I've been trying that, and it seems to work in the Bentley Class Editor, but when I apply the schema to an element the "Pick List" functionality isn't working.

chrisedjohn said:

I'm constrained to find a solution via the XML schema and VBA

If you want to work with XML using VBA, then you need an XML parser.  Microsoft's MSXML works with VBA. 

It's a low-level API.  You load a file (e.g. an EC Schema) into a document object model (DOM).  You use low-level MSXML functions to work with the DOM: for example, to query for a value or values.  To make that work you have to have a good understand of the XML query language and how that works to find one or more nodes.  It's best to use a tool such as XMLSpy to understand the query syntax.

What you're attempting with MicroStation V8i SSx and VBA will be challenging.

A Better Approach

You can avoid the hassle with XML and VBA by using C# to create a COM DLL.  C# lets you create a COM DLL, which you then call from VBA.  You design the interface to be implemented in the DLL: for example,

• GetWidgetSizeCount returns the number of widget sizes from Paul's ValueMap
• GetWidgetSize (ByVal index As Long) returns the value of widget size at the specified index

I recommend this because C# has excellent XML query and construction tools available, such as Language Embedded Query (LINQ).  Take a look at LINQPad, which provides some wonderful examples.

chrisedjohn said:

I'm constrained to find a solution via the XML schema and VBA

Please consider starting a new thread!

This relates to what I have been asking in this thread.

It is possible (and quite easy) to create PickLists for ItemTypes but the lists are strings only. I you attach such a PickList to an Int or a Double property you will get that "ECStandardValues TypeConverter cannot convert from System.String" message.

Bentleys answer was to use  the PickListHandler class (which I have not succeded to do). I think that this kind of basic data type conversion should be done automatically. If not, the PicklLists should have a data type so they can only be attached to a matching property. Otherwise you will have a dgn file that needs some application to work since the pick lists are stored in the file but not the handler.

/Krister