Exercise 4: Add Editing Capability

1. The final version of the myBASlookup routine is shown below, broken into sections to help you understand it. This is also available in the SAMPLES namespace as BASlookup2.mac.

2. The updated main section.

   
   public sub main()
       dim done
       do
           getsubmit(id, done) ' let user submit a string for lookup
           if id = 0 then continue do
           display(id, "table") ' display the chosen person
           edit(id) ' edit the chosen person
       loop until done
   end sub
   

   

3. The new edit subroutine.

   
   private sub edit(id as %Integer)
   ' allow user to choose, and edit their choice
       dim yn, newname, newphone, newintdob
       do
           input "Edit? (y/n): " ,yn : println
           if yn <> "y" then
               print "...no changes."
               exit sub
           end if
           ' try to lock the record
           if lock(^PersonD(id), 5) then exit do
           println "...someone else is editing this person"
       loop
       load(id)
       if reprompt(newname, newphone, newintdob) then
           input "Store? (y/n): ", yn : println
           if yn <> "y" then
               print "...no changes."
           else
               update(id, newname, newphone, newintdob)
           end if
       end if
       unlock(^PersonD(id))
   end sub
   

   

4. The new load subroutine.

   
   private sub load(id as %Integer)
   ' load a person into local variables
       dim rec
       rec = ^PersonD(id)
       name = piece(rec, "^", 1)
       phone = piece(rec, "^", 2)
       intdob = piece(rec, "^", 3)
   end sub
   

   

5. The updated display subroutine, that now calls load.

   
   private sub display(id As %Integer, style as %String)
   ' given an id, get data and write it
     load(id)
     if style = "line" then
       println name, space(2), phone, space(2), DateConvert(intdob, vbToExternal)
     else
       display@BASdatent2()
     end if
   end sub
   

   

6. The new reprompt function.

   
   private function reprompt(ByRef newname As %String,_
                        ByRef newphone As %String,_
                        ByRef newintdob As %Integer) As %Boolean
   ' show current data and allow user to update it
       dim changed, newdob
       changed = False
       do
           print "Name: ", name, "=> "
           input newname : println
           if (newname = "") then
               newname = name ' default
           else
               newname = validName@BASdatent2(newname)
           end if
       loop while newname = 0
       if name <> newname then changed = True
       do
           print "Phone (617): ", phone, "=> "
           input newphone : println
           if (newphone = "") then
               newphone = phone ' default
           else
               newphone = validPhone@BASdatent2(newphone)
           end if
       loop while newphone = 0
       if phone <> newphone then changed = True
       do
           print "DOB: ", DateConvert(intdob, vbToExternal), "=> "
           input newdob : println
           if (newdob = "") then
               newdob = DateConvert(intdob, vbToExternal) ' default
               newintdob = intdob
           else
               newintdob = validDOB@BASdatent2(newdob)
           end if
       loop while newintdob = 0
       if intdob <> newintdob then changed = True
       println : println
       return changed
   end function
   

   

7. The new update subroutine.

   
   private sub update(id As %Integer,_
                      newname As %String,_
                      newphone As %String,_
                      newintdob As %Integer)
   ' update ^PersonD and ^PersonI
       dim ln, fn, nln, nfn
       tstart ' start a transaction
       ^PersonD(id) = newname & "^" & newphone & "^" & newintdob ' store the record
       if newname <> name then ' erase old name and add new name to index
           ln = piece(name, ",", 1) : fn = piece(name, ",", 2)
           nln = piece(newname, ",", 1) : nfn = piece(newname, ",", 2)
           erase ^PersonI("Name", ln, fn, id)
           ^PersonI("Name", nln, nfn, id) = ""
       end if
       if newphone <> phone then ' erase old phone and add new phone to index
           erase ^PersonI("Phone", phone)
           ^PersonI("Phone", newphone) = id
       end if
       if newintdob <> intdob then ' erase old dob and add new dob to index
           erase ^PersonI("DOB", intdob, id)
           ^PersonI("DOB", newintdob, id) = ""
       end if
       tcommit ' commit the transaction
       println "...updated."
   end sub