The "hilight" fields are used on the Asset List View layout to show the current sort order. When you click on a column header in this layout you are clicking a button that runs a script that then sorts the records on the clicked column--updating the global HiliteSortedBy field with the name of the selected column along with "A" for ascending order and "D" for descending order. HilightLibrary is a global container field with two repetitons. One stores the graphic for ascending order and one stores the graphic for descending order. The other Hilite fields are calculation fields with "Container" as their result types. They will return either the graphic for ascending, the graphic for Descending or nothing depending on the value set in HiliteSortedBy by the script. This then controls which graphic appears by which column header to show the current sort order.
The similars fields are part of a system that controls what records appear in the portal to Similars on the Related Contacts tab on the Contact Form View Layout. Clicking the Radio button field on this tab sets a value in SimilarBy. The other fields are calculations that make it possible for the portal to Similars on this tab to list contacts with the same last name, City or Company as that of the current contact. This is a bit of an "old school" approach as FileMaker 11 supports portal filters and a filtered portal could list these similar contacts without all the extra calculation fields.
Global fields have more than one purpose. In this starter solution, they store values that, because global storage was specified, are accessible by any script and calculation, from any record, from any layout in the file. For example, when you click a column header on the Asset List View layout, the script can modify a global field and the same results are produced no matter which record is the current record at the time the column header was clicked. If the field modified by this script were not global, you'd be modifying the value of that field in just one record and the sort order graphics might change to show an incorrect graphic if you just selected a different record in the list since the fields would then show values from the fields in that record.
Thank you for your reply.
So would you consider these (Hilight & One & Similars) fields to be unnecessary for basic function of the database?
One and Similars are used in relationships that will thus not work if you remove those fields.
But would the database cease to function if those particular fields and relationships with those fields were not existent?
Any features that require that relationship will cease to function.
You may want to make a copy of your file, then remove these fields and test the file to see what breaks.