I have a reactive form which contains all the data needed for the page/component. However, I want to also store some information which is not part of the main data set but still needs to be stored as part of the component. For example, I need to know if Widget X is in inventory. If so, I can choose to take it from inventory, or I can make a new one. I need to store whether it is taken from inventory or not, but that information should not be stored as part of the main data set.
I know that I can put whatever I want into the form and then remove it before sending the data back to the server. The problem with that is that I want to have a Save button that is only enabled when the form is dirty. If someone changes whether they are taking the widget from inventory or not, it makes the form dirty. So I either need a separate form (but it needs to be able to be shown interspersed with the main form), or have a way to make certain controls not change the 'dirty' property on the form. Are either of those possible?
Hopefully this question makes sense. I did not want to post a whole bunch of code that wasn't totally relevant. I am using Angular 6.