Exercise 7: Third Lookup Class

Click here to return to the exercise description in the main part of the tutorial.

Using VS Code - ObjectScript, edit the Store() method of ObjectScript.DataEntry4. Add a TStart just before storing the user's answers in the ^PersonD global.
```
    // change all globals inside a transaction
    tstart
    set ^PersonD(id) = answers  // store the answers
```
Add a TCommit just after updating the indexes in the ^PersonI global.
```
    set $bit(^PersonI("Bitmap-ID", chunk), position) = 1
    tcommit
    write "...stored"    
```
Normally, only statements that set or kill globals should be between TStart and TCommit, but you'll leave Store() otherwise unchanged.
Click the Save and Compile buttons.
Change the top line of ObjectScript.Lookup2 to ObjectScript.Lookup3, and save it as ObjectScript.Lookup3.

Add this code to TakeAction() to give the user the option of deleting the record.

    // ask if user wants to delete
    read !, "Delete? (y/n): ", yn
    if ((yn = "y") || (yn = "Y")) {
        do ..Delete(id, record)
        quit
    }

Write the new Delete() method.

Class ObjectScript.Lookup3
{

/// delete chosen record (lock, start a txn, kill global nodes, commit txn, unlock)
ClassMethod Delete(id as %Integer, record as %String)
{
    // try to lock the record for 5 seconds
    lock +^PersonD(id):5
    if '$test {
        write "...someone else is editing this person. Try again later."
        quit
    }
    // retrieve data
    set $listbuild(name, phone, intdob) = record
    set last = $piece(name, ",", 1), first = $piece(name, ",", 2)
    set chunk = (id\64000) + 1, position = (id#64000) + 1
    
    // change all globals inside a transaction
    tstart
    kill ^PersonD(id)
    kill ^PersonI("Name", last, first, id)
    kill ^PersonI("Phone", phone)
    kill ^PersonI("DOB", intdob, id)
    set $bit(^PersonI("Bitmap-ID", chunk), position) = 0
    tcommit
    write "...deleted"
    lock -^PersonD(id)
}
}

Click the Save and Compile buttons.
Start the Terminal, and run your method to test the new deletion option, by typing do ##class(ObjectScript.Lookup3).Main().

Add this code to TakeAction() to give the user the option of editing the record.

    // ask if user wants to edit
    read !, "Edit? (y/n): ", yn
    if ((yn = "y") || (yn = "Y")) {
        do ..Edit(id, record)
        quit
    }

Write the new Edit() method.

Class ObjectScript.Lookup3
{

/// edit chosen record (lock, reprompt, compare, update globals, unlock)
ClassMethod Edit(id as %Integer, record as %String)
{
    // try to lock the record for 5 seconds
    lock +^PersonD(id):5
    if '$test {
        write "...someone else is editing this person. Try again later."
        quit
    }
    // show current data and prompt for updates
    do ..Reprompt(record, .newanswers)
    // if changes were made, update the record
    if '$listsame(record, newanswers) {do ..Update(id, record, newanswers)}
    lock -^PersonD(id)
}
}

Write the new Reprompt() method.

Class ObjectScript.Lookup3
{

/// prompt for updates - similar to ##class(ObjectScript.DataEntry4).Prompt()
ClassMethod Reprompt(currentdata as %String, ByRef newanswers as %String)
{   
    // get current name, phone, intdob so that they can be displayed within prompts
    set $listbuild(currentname, currentphone, currentintdob) = currentdata
    do {
        write !, "Name: ", currentname, " => "
        read newname
        // enter nothing to keep current value
        if (newname = "") {
            set newname = currentname
            quit
        }
     }
    while '##class(ObjectScript.DataEntry4).ValidName(newname)
    
    do {
        write !, "Phone: ", currentphone, " => "
        read "(617): ", newphone
        // enter nothing to keep current value
        if (newphone = "") {
            set newphone = currentphone
            quit
        }
    }
    while '##class(ObjectScript.DataEntry4).ValidPhone(.newphone)

    do {
        write !, "DOB: ", $zdate(currentintdob, 2), "=> "
        read newdob
        // enter nothing to keep current value
        if (newdob = "") {
            set newintdob = currentintdob
            quit
        }
    }
    while '##class(ObjectScript.DataEntry4).ValidDOB(newdob, .newintdob)

    set newanswers = $listbuild(newname, newphone, newintdob)
}
}

Write the new Update() method.

Class ObjectScript.Lookup3
{

/// save the updated record (start a txn, updating data and index globals using set and kill, commit txn)
ClassMethod Update(id as %Integer, currentdata as %String, ByRef newanswers as %String)
{
    read !, "Store updates? (y/n): ", yn  // ask if user wants to store
    // only go on if user says yes
    if ((yn '= "y") && (yn '= "Y")) {
        write "...not stored."
        quit
    }
    
    // get current and new data for comparisons
    set $listbuild(currentname, currentphone, currentintdob) = currentdata
    set currentlast = $piece(currentname, ",", 1), currentfirst = $piece(currentname, ",", 2)
    set $listbuild(newname, newphone, newintdob) = newanswers
    set newlast = $piece(newname, ",", 1), newfirst = $piece(newname, ",", 2)    

    // update all globals inside a transaction
    // only update indexes if the data was changed    
    tstart
    set ^PersonD(id) = newanswers
    if (newname '= currentname) {
        // kill old name and add new name to index
        kill ^PersonI("Name", currentlast, currentfirst, id)
        set ^PersonI("Name", newlast, newfirst, id) = ""
    }
    if (newphone '= currentphone) {
        // kill old phone and add new phone to index
        kill ^PersonI("Phone", currentphone)
        set ^PersonI("Phone", newphone) = id
    }
    if (newintdob '= currentintdob) {
        // kill old dob and add new dob to index
        kill ^PersonI("DOB", currentintdob, id)
        set ^PersonI("DOB", newintdob, id) = ""
    }
    tcommit  // commit the transaction
    write "...updated."    
}
}

Click the Save and Compile buttons.
Start the Terminal, and run your method to test the new editing option, by typing do ##class(ObjectScript.Lookup3).Main().

Exercise 6: Second Lookup Class