Reset Numeric parameter value back to 'empty'

[Keith_Wilkinson]

I've been working through producing a curtain wall schedule and it's just about where it needs to be.  However I've noticed that for one of the conditions the schedule looks better if a paraemeter field is left empty rather than applying an integer value.

The thing is, for rooms where the integer value has already been applied it doesn't appear to be possible to reset this to being empty again. 

Anyone know if there is a way to do this?  I've tried in both a room schedule and in the room properties to delete the value that is currently inserted.

Cheers

K.

[Alisder.Brown]

Keith

Integer value for what parameter? It seems to work fine for me.

The room number, for instance, does what you are looking for. Simply delete the number and thats it. 

cheers

[Keith_Wilkinson]

Hi Alisder,

I have a parameter called 'ventilation type' which is assigned to rooms.  It's just an integer parameter but when I try to delete it in the schedule or in the room properties it returns the attached error...

[alan.quinn]

Without the file and additional screen shots on what you are doing and the unexpected results it will be had to troubleshoot this one. You can either attach here or I'll create an internal case and you can upload there.

Thank for posting.

[L.Maas]

I have noticed similar behaviour in other (database) programs. When first setup a record is 'emtpy' (often 'null'). As soon as you enter a value lets say 1 and confirm it thats the value assigned. However when you want to make it empty again it refuses, because he now expects a certain valid input.

In a database they often use a 'null' value for this just meaning nothing assigend yet. Depending on the way things are programmed you as user can not set it back to 'null' and now the software expects a valid input. In case for a number or integer this means you would have to fall back to the value '0' or something.

If this is the case in your situation I do not know. More information from your side would be needed, exactly how and where it happens.

[Keith_Wilkinson]

Hi Alan,

The attached video shows the problem.  The parameter is set up as a project parameter and then assigned to walls in this case.  It's just an integer parameter.  When you initially select the wall the field is completely blank, however as soon as you assign a value and then try to delete it to return the field to being blank it returns an error.

Hopefully this is sufficient info to highlight the problem.

[L.Maas]

Keith,

It is what I described in my previous post. As soon as you have assigned it a value you can not make it empty again.

You would have to take drastic measure to get it back to empty. Like delete the wall and place a new wall or delete the project parameter and add it againn.

Only certain parameters can be made empty again, like text.

[GPR_MN]

In times of Revit hardship, i turn to the lessons of battle and conflict, often extreme and regrettable.

In this instance, I would cite Officer Ripley.. Nuke it from orbit. 

I have equipment that managment would prefer display blank fields when they are existing, but it could be the same family type as new equipment which will need to display values in schedule. rather than creating a similar named parameter and transfering each dimension value to a new text parameter for each component and leaving the existing types blank; duplicate and rename the component, delete the parameter from the family parameters in the family editor, reload and change your element to the new modified type. if the paramter also exists as a project parameter the field should remain in the schedule but now be blank.

[rosskirby]

It's one of those things you can't just undo.  When it's happened to me, I just replace the parameter value with "-" or something similar. 

[L.Maas]

As I mentioned in my earlier post. This is typically something used in databases, a null 'value', meaning something like nothing assigned yet. The Revit interface will not allow you to set  it back to null. When parameter is an integer it will after first assignment expect a number.

So the only possible solution I can see is set it directly in the database or using the API (Dynamo) to reset it.

[gsucci]

see next reply.....

[really? cannot delete my own reply?]

[gsucci]

This is a major issue in many occasions.

There are really no reasons why a field should not be able to return to a Null status, its just a matter of implementing this feature.

See attached screen cap, the sheet index uses an integer parameter for each issuance, so that I can black-out the cell when the value is > 0 using conditional formatting.

This is the equivalent of having the "X" or the dot in the corresponding issuance column, in an architectural set.

This allows me to also count the sheet issued for each issuance, by simply totaling the 1s in those field(s).

Now, this works until you only add sheets to the issuance, that is, when you go from null, (blank) to 1, however, if you make a mistake, or if a sheet is not being issued anymore, there is no way to blank out the field again.

So, the zero will show, compromising the whole appearance of the table.

Is there a way in Dynamo to reset these fields to blank?

Is this feature being requested and considered by Autodesk? Can we "vote" for it?

Thank you

[L.Maas]

As far as I can tell there is no function in Dynamo that can do this.

There is a Revit Idea Station where you can post your ideas and have people vote for it.

[Curtis.Ridenour]

I agree this is an issue and should be addressed.

If the family parameter is a built in parameter like Cost, you can't even delete the parameter to reset it.

[dubindesign]

I am following this thread as well.  Sometimes "empty" and "0" are really not the same thing.  In my case I have some fields in my window schedule for "simulated U value" and "simulated SHGC", which I have values for for some window types but not for all.  If I do not have a value to input, I don't want to see a zero, I want to see an empty cell.  So, if I've made a mistake and entered a value, I can't return to the innocence of the empty cell...

[ToanDN]

A workaround is using a calculated parameter to present on the schedule and hide the original field.

[krzystoff]

Thanks, that workaround is helpful where this problem occurs within a schedule.  

However, we also have the same Revit glitch with integers in Family Parameters, including inbuilt properties such as Walls which have acoustic/fire ratings; once the wall types have information added there is no way to remove the '0' value, deleting the parameter isn't an option and we use that same data in Wall Tags, so we're really hoping for a Revit bug fix.

[ToanDN]

@krzystoff

Which version you are using?  From 2017 you can add calculated value in Tag families the same way you do in a schedule.

[lionel.kai]

I created this idea: be able to reset parameter to NULL

[SteveKStafford]

Fwiw, the only way I've observed a parameter value being null is immediately after it is created and has not been used...yet. That is a state of ambiguity which ordinarily Revit abhors. Once a value has been entered Revit's bias kicks in.

The reasoning is that an empty cell in a schedule can mean, "oops I forgot to enter a value" just as much as "nothing". It's the same reason Revit uses Yes/No instead of the common matrix dot that we've used for years.

Graphically it annoys the heck out of people because it isn't a pleasing to look at, however every cell has a value and it can only be yes or no. In this case it could be argued that the parameter ought to be displaying a value immediately versus being gray or disabled (null) until a value has been entered. In the case of a yes/no parameter, Revit is waiting for us to tell it which it is. Their logic is a number or integer parameter must hold a value once that bias has kicked in.