Advice re Error Handling

[kiffab]

Hi Guys

I am building a monitoring tool which is almost complete.

This is in the form of a dashboard reading data from various log files, databases, etc. As you can imagine with various data sources, there is a possibility that the application can error (missing files, files refreshing, SQL down, etc).

Most of the AutoIt errors I have seen exit upon failure. What's the best way to handle this in my app? I plan to write to a database by calling a function before it closes. For example :

DBConnect('Error', 'Server X', $time, 'unable to connect to sql database')

What is the cleanest way to "error" but continue running? Use the "break" command?

Thanks, appreciate any input.

K.

[jdelaney]

You need to validate things prior to performing actions...such as IsObj() for db...that way, you don't perform methods, or get properties, from things you expect to be an object, but are not...same is true for files, through FileOpen, with your proper mode, and verifying not @error

[water]

I would split your script into several functions.

The main function displays the dashboard. For every data type I would create a separate function (read a file, read a SQL database etc.) to retrieve the data. Each of this functions returns the data (on success) or sets @error. If @error is set the main function then can display the error message or a "Not available" for the the corresponding data.

Each retrieve function has to handle all possible errors and set @error accordingly.

[kiffab]

Hi Water

That is how it works. I have a GUI that just calls the function. Each function exists in it's own file and updates the GUI in some way.

An example may help:

Func SQLCheck()

$time = @YEAR & "-" & @MON & "-" & @MDAY & " " & @HOUR & ":" & @MIN & ":" & @SEC

TCPStartup()
$server = TCPNameToIP("MyDatabaseServer")
$port = 1433

$socket = TCPConnect($server,$port)
Switch $socket
    Case -1
            $SQLCheck = 1
                If $SQLCheck <> $SQLCheck_old Then
                    GUICtrlSetData($06_schematic_sql , _SetImage($06_schematic_sql, @ScriptDir & "buttonsschematic_down.png"))
                    DBConnect('SQL', 'SQL DB', $time, 'Down')
                    $SQLCheck_Old = $SQLCheck
                EndIf

    Case Else
            $SQLCheck = 2
                If $SQLCheck <> $SQLCheck_old Then

                    GUICtrlSetData($06_schematic_sql , _SetImage($06_schematic_sql, @ScriptDir & "buttonsschematic_up.png"))
                    $SQLCheck_Old = $SQLCheck
                EndIf
EndSwitch

TCPShutdown()

EndFunc

SQLcheck flags are set to 0 when the main GUI is reset or opened for the first time. I use these to try and update the image only when required (i.e. status change)

[water]

Looks good.

You just have to make sure that you grab all possible errors.

So after TCPStartup and TCPNameToIP I would insert a check to make sure that @error = 0. If not, display the error sign.