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be able to reset parameter to NULL

be able to reset parameter to NULL

If you set a value to a parameter (even Text), there's no way to get it back to "blank", and will therefore not group with other (new) elements properly. This example schedule is being sorted by Level, Type, z Offset, & Comments:


3840.02 GB schedule example (highlighted).png


WORKAROUND: In order to get the highlighted elements to display (group) correctly, you need to set the "empty" one to a value, then delete it (since Revit treats an empty string as different than a null value) so that it groups with existing elements that had their Comments field used & cleared. The problem is that you need to MANUALLY do this for ALL new elements from then on...


FYI, the schedule above is being used to do some QC correction (a user had incorrectly used both Type and Element comments instead of the Type Mark parameter).


Related idea & discussion:


Null value needed for dimensional parameters with scheduling capability - to display the null in a schedule as a "-", "---", "n/a", etc. [should make separate idea for casting dimension to a string]


Reset Numeric parameter value back to 'empty' - for an Integer parameter to be blank instead of showing "0" (zero), with steps to reset to null if it's not a built-in parameter?





When you set up a number parameter - its value is blank.


Once you add a value - the parameter can never be set back to blank, only a number is accepted.


This is a real pain when dealing with schedules where some (doors, example) parameter requires a number value whereas most don't.


Text parameters don't have this problem.


Can we make the operation the same for all parameters and allow a blank value for numbers.




It would be better to initialize values appropriately. For example, zero for numeric values. false for booleans, etc. A non-text parameter value should never be empty or uninitialized. Blank values would be better handled through a format setting in the tag or schedule field as it is with Excel: I.e., 'leave zero values blank'.


Yea, I wouldn't disagree with your comments - I think my main issue is that Revit is inconsistent in how it handle this.


Revit 'allows' a blank' initial value, but from then on it cannot be set back to blank.


I would be happy if number parameters always showed a value - zero when initialised and as you say, a format setting could handle the display.






I also want to allow a blank value for numbers


for me this would be not good to have zero from beginning. I prefer to have control zero or deactivate so no number see below why 


...for MEP we place dozen value in space tags and with shaft spaces if value is not activated tags are small once by mistake activate value and we need to keep schedule looks terrible


see standard tag no one activate number

and here by mistake someone activated number and zero need to remain 

so we want to allow a blank values for numbers



2016-10-25 11_33_43Sim2015_C.png




If you create a number parameter, initially it will be blank.


But once you've entered a value, you can never set it back to blank.


You can do this for text parameters.


Lets have some consistency here, allow blank values.


(For a formula Autodesk can set blank to generate the same value as zero)

Treating empty the same as null in grouping, sorting and filtering of parameters would also achieve the desired result for text parameters.


Now the integer fields which are empty cannot be used in formula's (calculated parameters) in schedules.


For example for parameter 'Test' which is an integer value, the formula 'if(Test = empty , 0, Test)

The formula would change all empty integer values of the 'Test' parameter into 0 and if this field is not empty it will remain unchanged.

Unfortunately there is currently no option to use this empty integer value in formula's...


I also would like resolution to this topic, but having the 'null' become 0 may not fit every circumstance. 0 is useful for addition/subtraction, but it could really screw things up with multiply/divide. It would be nice if each integer parameter could have a 'default to 0 or 1' option when null so the user could choose to be correct for each circumstance.

Let's improve the conditional formatting feature to allow text/symbol overrides instead of just color. Right now, if a schedule parameter is set to any of the default calculated values, such as flow, pressure loss, integer or number based, any null value is represented by a 0. Instead we need to bring back the ability to have a "-" dash or N/A text override value to be used, instead of just a color fill (which is our current solution) from the current conditional formatting behavior.


An excellent idea. I have often been frustrated by this inability. I use an integer parameter to manually sort sheets when the desired order needs to be customized. Usually I can keep this parameter blank for most sheet groupings. However, if an integer is accidentally added to a sheet that doesn't need manual sorting, I must resort to setting all of the other sheets in that group to the same integer so that it sorts typically. If I could just reset the value to null/empty, it would save time and frustration.


In my schedule, some elements consist of a total cost based on a Length parameter. Formula = ([meter price] *[length (mm)] /1000). Other Elements in the same schedule are not Line Based, so their formula is ([unit price]* [Unit Count Total]) .


So far no problems.


When i try to combine the two elements in a total cost parameter (([meter price] *[length (mm)] /1000)+([unit price]* [Unit Count Total])), Revit ignores the row value for the element based on number of units. This is because i can't ignore the Null value for the Length parameter in the element based on unit count.


In programs like Excel and Access it is possible to ignore ''blank'' Null values. So it should be possible in the year 2020 to use it in Revit aswell.


that is important for ifc exporting! plz add this function ! 


Very important not to have to show zeros in tags


Very important to be able to hide 0 in tags or make it possible to auto-hide 0 values

Also, Null value should be able to have a similar override line Varies has in schedules so we can replace it with "N/A" or "-" for instance


LOL. 9 votes in 2 minutes - someone must have been running a training and said "here, vote for this one". 👍 If only I could get the same response from MY guys when I tell them to vote for something...


This must happen!

An operator that reported true if the value was undefined would solve the myriad of forum and ideas that deal with this problem. In other programming languages there is "empty()", so the example formula would be 'if(empty(Test), 0, Test)'.




Can Revit please add the functionality to display "0" values as N/A, blank or dash? We often have schedules where not all the parameters apply (eg. Air handling unit schedules with supply fan, return fan, heating and cooling coils - not every air handling unit has each component, but we want to show them in one schedule). It looks like are some complicated workarounds but this seems like a fairly basic functionality that could be added under conditional formatting. The alternative using text parameters for everything, but that defeats the whole point of Revit.


When working with data in Revit, it's quite important to be able to fully control the value of properties. This also includes setting a value to NULL for indicating that the value has not been decided yet. Setting a nummeric value to 0 is no solution, as this states that the designer/engineer has chosen 0 as the correct value, when in fact they don't have decided on a value.

I'm going to take back my earlier comment in case AutoDesk think I had offered an easy way out. The more I work with databases the more I want a BIM application that deals with building data first, rather than a 3D drawing app that lets you attach some limited values to things you've drawn. With data, "not yet determined" is quite different from "zero". Put it this way, if you climb out your office window is the risk of falling to your death zero (i.e. default assigned value) or "not yet determined" (i.e. null in the database)?

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