Handle cases where there is no owner

[emteknetnz]

As part of saving the relation between an Owner and Link on Link creation you can get into a state where the Owner has yet to be saved, such as creating a new Owner on a GridField.

In these instances, it probably makes sense to not render the LinkField component normally, and instead have a message in the LinkField along the lines of "Save the Owner first"

We can simply check to see if the ownerID prop in the LinkField component is 0 or not as a condition for showing the message

PR

• ENH Show save record first text on unsaved owners #159

[GuySartorelli]

@emteknetnz Did you mean to open this in the linkfield repo?
I'll migrate it there

[GuySartorelli]

PR merged