Formula help: How to index one entity in a collection?

[Chr1sG]

See here:

Formula to assign number based on sorting

I don’t know why it took me so long to figure out a more elegant solution to this, but here is an example of a formula that will tell you the relative position of a Task entity amongst all the Tasks related to a common parent Project: (Find(Project.Tasks.Sort([Start Date]).Join("#" + Right("000" + [Public Id], 4), ""),"#" + Right("000" + [Public Id], 4)) + 4) / 5 In this example, the position is given for items based on their start date, but it can equally be used to get the position of items…

A general formula for getting the index of an entity within a collection:

(Find(Collection.Entities.Sort([Parameter to sort on]).Join("#" + Right("000" + [Public Id], 4), ""),"#" + Right("000" + [Public Id], 4)) + 4) / 5

I expect it will slow down the formula service if you have a large collection size though