Adding validate functions can be a bit odd, because unlike views, there isn't a nice interface in Futon for us to use. The quickest way to add the validate_doc_update function is to treat it like a normal field in our document and type the code right into the value. It's a bit strange, but it is the quickest way to adjust design documents. At the end of the chapter, I'll give you some resources if you want to get a bit cleaner with how you manage design documents.
1. Open your browser and go to Futon (
http://localhost:5984/_utils/).2. Make sure that you are logged in to the
adminaccount by checking that the bottom right column says Welcome.3. Go to our
vergedatabase by clicking onverge.4. Click on our
_design/applicationdesign document.5. Click on Add Field, and call this field
validate_doc_update.6. In the Value text area, add the following code (formatting and indents don...