For a node I am modifying I have one or more hidden configuration nodes (let's call these parent nodes A,B,C...). To start, assume there are no parent nodes configured yet. A child node (child node 1) is dragged from the palette onto the editor panel and as part of it's configuration it needs to configure a parent node, which then opens the parent node's configuration panel, where various options are selected as needed. Clicking 'Done' creates parent node A, with which child node 1 is now associated and after selecting various child node options clicking 'Done' then completes the process. We now have child node A1 associated with parent node A (all very similar to say the serial node or mqtt node).
Dragging another child node from the palette onto the editor (child node 2) and opening its configuration shows parent node A, which can be selected, or another parent node can be created. For simplicity's sake, we'll assume child node 2 also uses parent node A. We can keep doing this and create a set of say child nodes A1-A8 all associated with parent node A. So far, nothing new under the sun and in my case this all works.
However, depending on the type of parent node created, up to 8 or 16 child nodes can be associated with it. Each of parent node A's child nodes must have one of it's parameters (say X) be unique from the other child nodes. So X of child A1, must be different from X of child A2, etc. No two child nodes A1-A8 can have the same value for X
X is selected from a drop-down of values ranging from 0 thru 7. What I would like to achieve is keeping track of the already selected values for X in previous child nodes and disabling those values when a new child node is created. I already know how to disable options in a selection list, so that is not the issue. What is the issue is how to keep track of previously selected X-values, preferably without reverting to the runtime, so that a bunch of child nodes can be created without clicking deploy. I don't actually need to know which child node has a selected X-value, just that an X-value can no longer be selected.
I'm thinking that parent node A could have a hidden attribute, where it keeps an array of previously selected values. When a new child is created and associated with A, it could use that array to disable selection of already selected X-values. But how does parent A get the X-value selected in child A1, and subsequently, how does child A2 get the array of X-values from parent A?