To increase the flexibility of property value population, 4 default value options in the ‘Edit Property’ dialogue were introduced by the 2.16 release
In order to benefit from Best Practices related to property value population, you are strongly recommended to read this article in conjunction with the companion article on Evaluation Mode
Here is the documented behaviour of the default value options settings and you should choose the correct option based on the desired behaviour:
Conceptually "Default value" and "Fixed value" can be thought of as opposites: a Default Value will not populate a cell that already has a value, only if it is blank; a Fixed value will overwrite anything that is entered into a cell i.e. even if it blank or a new value entered
* This can be thought of as a property of a hidden node that is the ultimate root of the tree – the so-called ‘Mother of all Nodes’
† When using the Default / Inherited / Fixed settings the cells appear to contain a value but are blank when clicked on. Values set using ‘Initial’ are persisted into the cell itself.
- If you only need the expression to be calculated once (or rarely) and remain static most of the time , you can prevent re-evaluation, providing more control. Prevent your expressions being re-calculated when you do not want them to by adding a !! to the end
- Do not use the splash command format with expressions in the default value field
!! means result of the expression
!!* means result of the expression applied to all nodes (more typically uses in the cell rather than 'edit property')
As the expression is in the edit property dialogue is written to all cells anyway, and using the splash command here may cause adverse behaviour
- When there is a property using an expression dependent on another cell (basic example: copy of another cell's value), particularly a value unlikely to change, the Best Practice in this case is to set the property to Fixed Value and evaluation mode to On Demand as it runs OrgVue's internal fetch cycles most efficiently: subsequent updates can then be run with the Formula button, which is enabled when these two modes are used in conjunction. The button appears at the top of the column in the Worksheet view.
- For other modes other than the previous, the easiest way to force property reevaluation is to run a blank splash command !!* in the relevant cell, which sets cells to blank and therefore the default options setting is reevaluated. For obvious reasons, beware of running this in conjunction with Default Value
This article was authored by Ben Marshall from the OrgVue Consulting Team