MarkdownKit Review

Markdown is a popular text formatting syntax in use all over the web. Markdown was designed to be human readable in plain text, and formatting parsers are available for many different formats.

There are a few different parsers for Xojo, available in both add-on and plugin format. Garry Pettet provided MarkdownKit for us to look at and review. MarkdownKit is written entirely in Xojo code, is fully CommonMark compliant, and generates HTML.

MarkdownKit is implemented with both String and Text versions, and is designed for both Desktop and iOS projects. MarkdownKit is provided as full source code, and includes documentation as well as examples.

With everything provided, MarkdownKit is very easy to use. It really is as simple as one line. dim sHTML as String = MarkdownKit.ToHTML(SomeMarkdownString) The output can then be passed into an HTMLViewer and displayed. This can all be done so fast you get near live rendering.

The way MarkdownKit renders the input is impressive. A MarkdownKit document is parsed into a syntax tree so that an implementation of the rendering interface can walk the document. What we get from all that is a fast and accurate Markdown renderer. And wow is it fast. The demo application really illustrates the speed of MarkdownKit.

Overall MarkdownKit has proven to be speedy, well documented, easy to use, expandable, and CommonMark compliant. MarkdownKit is a great Markdown renderer written entirely in Xojo code. If you don’t yet have a Markdown renderer in your toolkit, MarkdownKit is a solid option.

More information about MarkdownKit, pricing, and the demo downloads are available at the MarkdownKit Webpage: https://garrypettet.com/xojo-addons/markdownkit

Task Timer 6

We are pleased to announce the newest version of Task Timer. It has been four years since our last update to Task Timer, so we’ve started from the ground up. Task Timer 6 is faster than ever before and ready for the future!

Never lose money again! Track your time accurately with Task Timer. Get back lost time by knowing how much time was spent on any project. Use historical time tracking data to improve your estimates. Never again find yourself guessing at billing.

Projects and timers are now easier to manage, start, and stop. Managing time sessions is now faster and easier to do. The events manager no longer blocks the main window, and we fixed a couple bugs along the way.

Version 6 will automatically import and convert all existing Task Timer 5 data. You won’t miss a beat. Stop all timers in Task Timer 5 and close Task Timer 5. Then simply open Task Timer 6 and import.

Task Timer 6 is a crucial update. Unfortunately, the previous version is near it’s lifecycle end by more than one cause. We regret that we will be unable to support Task Timer 5 in any way due to the final closure of the commercial licensing server we were using.

To encourage everyone to upgrade, the Task Timer 6 software will automatically offer an upgrade discount. If there are any troubles with the automatic process, please don’t hesitate to contact us at support@bkeeney.com!

Download Task Timer 6 today! https://bkeeney.com/tasktimer

Test Data

At XDC 2019 my session was titled Xojo Design Mistakes (the alternate but way longer title was ‘Thankfully time travel doesn’t exist or my future self might travel back and murder my younger self for the stupid coding mistakes I’ve made’).  These are things that I’ve discovered over the years, both in my own projects and in other peoples projects that are just plain wrong or less than ideal.  This will be an on-going series since I had well over 50 slides and left 150 out.  So when I get bored I’ll bring these topics up.

Nearly all of our consulting projects are database driven applications.  It’s why we’ve created the tools to help with these projects like ARGen, which simplifies our interactions with the database, and BKS Shorts, which is our own reporting tool.  These tools are invaluable in getting our work done in a timely matter.

In a database application it’s typical to have a List of something.  A common example of this is a Customers list.  In that list the client typically wants the ability to Create, Read, Update, and Delete (or CRUD) a customer with varying degrees of rules behind it (like do they have permissions to add or delete a customer?).

During development we get the List form going, add the controls to be able to add a new record.  Then we create the Add/Edit form that allows us to test those capabilities.  We create a few, update a few, delete a few customers and then move on.  Maybe the client wants search capabilities so we add that to the List window and when we’ve tested it against our half dozen or so records we move on to the next task.

There is nothing wrong with this process.  It works and it’s fairly efficient as far as it does.  However, there’s one thing we’ve skipped that’s really important but also difficult to achieve.

So far we’ve test with *maybe* a dozen records.  What happens when the client adds 10,000, or 100,000 Customer records?  Does the list form take a long time to load?  Does the search function take a long time?  What about the Customer popup menu’s that you’ve scattered throughout the project – are those now slow, unwieldy, and unusable?

Unfortunately, with the way we implemented the project we don’t know how any of this works since we only have a dozen records.  So it’s really important to have adequate amounts of test data.  Creating 10,000 new customers using your new interface would take a long time.  So what can you do?

There are tools out there that will help generate data sets.  These tools allow you to create thousands, even millions of rows of realistic data.  Randomized male and female first names along with a last names is a great way to generate customer names.  Many tools allow you to add random dates in a range, random IP addresses, random values from a  list you provide and so on.  The sky is the limit when it comes to what sort of data developers need.

Now, when you do your testing you see how your application reacts with a lot of data.  I almost guarantee that it will act different.  Do you need to switch to a data-on-demand listbox?  Do you need to put an index on a common searchable field to speed up indexing?  Do you need to implement Full Text Search in your database?  Having a huge amount of data will answer these questions for you.

I once worked on an accounting application in VB6 where the original database designer using an Access database and did an account balance on the fly iterating through bills, checks, journal entries, etc. With a few thousand rows of data in each table this process took a second or two for all balances on a local machine. When this database was accessed over the network it took 5 to 7 seconds. When we converted our first client database it took 30 to 40 seconds for EACH account! Obviously this was not acceptable performance from an accounting application meant to be used daily by general contractors with hundreds of employees and tens of thousands of customers. The solution was to have a current balance value that was stored and then updated when a transaction occurred. We could have saved ourselves hundreds of hours of rushed development time (and much stress and heartache) if we had tested with large amounts of data much earlier in the process.

I mentioned adding an Index to a field earlier. One word of caution on this: it’s tempting to add an index to every field you’re searching on. Don’t do this! Only added indexes to the most important fields in a table. For a customer maybe the two most important fields are phone number and name even though you search on City and things like that. Indexing is extra work for the database so performance can take a signifiant hit with indexing a field.

Since the toolI’ve been using to create test data is no longer being sold I’m curious what you’d recommend.  Do you have a favorite tool?  Or is this a tool that would be of use to the community?

Happy Coding!

Exception Handling

At XDC 2019 my session was titled Xojo Design Mistakes (the alternate but way longer title was ‘Thankfully time travel doesn’t exist or my future self might travel back and murder my younger self for the stupid coding mistakes I’ve made’).  These are things that I’ve discovered over the years, both in my own projects and in other peoples projects that are just plain wrong or less than ideal.  This will be an on-going series since I had well over 50 slides and left about 150 out.  So when I get bored I’ll bring these topics up.

Xojo has evolved over the years.  Many of the global framework (the classic framework) classes set an error bit or error code when an error occurred and the developer has to check to see if there is an error and deal with it accordingly.  Many developers don’t check – mainly out of ignorance, and that’s a problem.

The newer (but soon to be deprecated) Xojo framework (and we’ve been told the API 2.0 framework as well) throws Runtime Exceptions to report errors.  The exceptions definitely get your attention because, well, an exception happened.  The problem is that many Xojo developers don’t catch exceptions anywhere in their application.  This results in dialogs like this:

Users hate seeing this and it’s unhelpful to the developer because it tells them NOTHING about the cause of the error.  And, their application quits making the user really unhappy.

The Application object in every Xojo project has an UnhandledException event made to catch any exceptions not caught anywhere else.  It’s declaration is this:

By returning True you can keep the application from quitting.  Just returning true is just as bad, perhaps worse, than the first dialog because the app had an exception and the app might now be in an unknown state and the user has no idea that it happened.  At this point what happens is anyone’s guess.  Silent errors are a bad thing.  Never do this.

A better way is to use the App.UnhandledException event to report that something happened so the user can decide what to do.  Ideally, you’d like to get some information from them so the developer can get an idea of what’s caused the exception.  What were they doing when the exception happened?  What is the stack trace?

If you are are unaware of what the Stack Trace is this is the call stack your app is current in when the exception occurred.  Maybe you called the Pushbutton1.Action that called ClassA.Method1 which called Global.MethodB which called Global.MethodC.  This information (although not as neatly) is in the stack trace.  It is sometimes invaluable in helping find and fix bugs.

BKeeney Software created a generic error reporting system years ago that when put in the App.UnhandledException shows the user a dialog like this when an exception occurs.  You can tailor the message to suit your needs.

We generally don’t quit apps when exceptions are raised, but it is something that some clients want.  The Report Error button then takes them to another dialog asking for more information.  The user can easily bypass this section by pressing OK.  Hopefully your users are nice and they’ll report the error.

If they select the E-Mail Bug Report or Save Text File button without putting anything in the TextField we present a dialog begging them for more information.  Sometimes this works but not always.

Regardless, the next step in the process creates an email or text file.  Sending an email requires the use of the computers built-in email client and we find this has advantages in that we get the users email address.  A sample email goes something like this:

In our email we get the type of exception, the time, the method location, basic system information, the user description (hopefully), and the stack trace.  A vast majority of the time that’s enough to find a bug.  Sometimes it’s not but at least you can email them back.  The text file still requires them to send it to us via email so we helpfully include the support email address.

If you want to play around with this example, please download it from https://www.dropbox.com/s/3uxyqvjf4wvjrpg/Exception%20Handler%201.0.zip?dl=0.  Feel free to use in your own code however it is provided as-is with no warranty.  We cannot provide support.

You need to implement something similar to this exception handling strategy.  It will help your customers provide feedback to you so you can fix bugs.  This seems like the least you should do.  With the upcoming API 2.0 with API’s that throw exceptions rather than setting error codes this will be more important than ever.  I’m sure I’ll talk more about Exception handling strategies once API 2.0 is released.

What other types of things do you do for error reporting?