< Back to Blog

One of the Most Powerful Debugging Practices

Industry

The hard to find bugs generally occur under circumstances that are relatively rare. After all, if the program re-boots your system every time you run it, you will usually fix that error. Some of these rare cases are caused by executing a code path that has never been executed before. When your program first starts, you will generally create a number of objects. You have a code path you take if those constructors throw exceptions, but have they ever failed?

If not, you have an accident waiting to happen. What does your program actually do when that particular constructor fails? As long as you have not tested a code path, you have not fully tested your program. Be sure that you exercise every code path. If you have an "if () ... else ..." and you have always executed the "else" part, then the "if" part is a bug waiting to happen.

There is a very simple way to handle this, and do so in a manner that will help you as you first run your code. The beauty of using traps is it helps you immediately, so that you will quickly find that you automatically put them in as you write code.

This is composed of two methods, trap() and trap(bool) – I have included Java, C++, & assembler examples at the, but for illustration I will use C# here. What a trap does is drop you into the debugger when you hit one. First the example, then why this is so useful

// Open an XML file
XmlReader reader;
if (string.IsNullOrEmpty(username)) {
   Trap.Trap();
   reader = XmlReader.Create(filename, xmlSettings);
} else {
   Trap.Trap(!hasDomain);
   Trap.Trap(hasDomain);
   XmlUrlResolver resolver = new XmlZipResolver();
   resolver.Credentials = hasDomain ? new NetworkCredential(user, password, domain) : new NetworkCredential(user, password);
   xmlSettings.XmlResolver = resolver;
   reader = XmlReader.Create(filename, xmlSettings);
}

The Immediate Pay-Off

Why is this a big help from the start? Because it helps you single step through each part of your code once. In the code above you probably test at first with no username so you'll fall in the debugger on the first trap. You mark it and then step over the Create. You may single step a couple of lines after to make sure the xml is good, then you go.

Note: The way I mark a trap I hit is to put ** at the start of that line. When I finish a debug session a simple compile will show me every place I added the **. Because I add the ** to the same line, line numbers stay the same and the debugger matches your source line correctly (if you delete the line with the trap when you hit it the debugger will be off by one line anywhere further down in that file).

Ok, so you've been working on this module for a couple of days, it's all working well and you decide to try an XML file that requires credentials. When you do the debugger will stop at the top of the else. You then step through the code opening the XML file with credentials. The beauty of this approach is you don't need to remember that you haven't walked through these 4 lines of code. You don't need to go find those 4 lines of code. It just drops you there in the debugger. I think this is one of the most powerful debugging tools I use because I now easily single step through every line of my code – and find enough issues from this practice to make it well worth it.

The Secondary Pay-Off

This practice also provides a second great pay-off. All the traps removed initially are either very common code paths or paths specifically hit due to unit testing. So when you are "done" with a module and all your tests are written, any remaining traps are indicators of tests that remain to be written. You now have a very easy way to identify remaining unit tests that need to be written.

And the traps are implemented so they only run on a debug build. So you can ship code with traps in it (we shouldn't, but we all do) and it will have no impact on the release version.

Implementation

C# & Java - Download Trap.zip

C++ & Assembler – in my (free) book No Bugs!

Tags Start & End

Tags Can Start & End Anywhere

Appendix B

.NET code for multi-page image output

Appendix A

Java code for multi-page image output

Data Bin Search

The Data Bin can now be searched to find a table, column, node or other piece of data without scrolling through it all.

Shrink to Fit

This will shrink the contents of a cell until it fits the defined cell size.

Time Zone Conversion

A new Windward macro has been added to help with converting dates and times from UTC time to the local time zone.

Image Output Format

New image output formats added.

PostScript Output Format

PostScript, commonly used with printers and printing companies, has been added as an additional output format.

New and Improved Datasets (Designer, Java Engine, .NET Engine)

Datasets have been re-written from scratch to be more powerful and easier to use.

Stored Procedure Wizard (Designer)

This works for all tag types that are connected to a SQL-based data source (Microsoft SQL Server, Oracle, MySQL, or DB2).

Boolean Conditional Wizard (Designer)

Before, conditional statements could only be written manually. Now they can also be built using our intuitive Wizard interface.

Reorganized Ribbon

The ribbon menus have been re-organized and consolidated to improve the report design workflow.

XPath 2.0 as Data Source

Adds various capabilities such as inequalities,descending sort, joins, and other functions.

SQL Select Debugger

SQL Select  Debugger

  • The look and feel was improved
  • Stored Procedure Wizard
  • Improved Exceptions pane

Tag Editor/Tag Selector

Added a Query tab as a field for typing or pasting in a select statement

  • Color Coding of Keywords
  • TypeAhead
  • Evaluate is now "Preview"

Rename a Datasource

All tags using that Data source will be automatically updated with that name.

Connecting to a Data Source

New single interface to replace 2 separate dialog boxes

Tag Tree

Provides a display of all the tags in the template, structures as they are placed in the template. Provides an easy way to see the structure, go to any tag, and see the properties of a tag.

Added Javelin into the RESTful Engine

Support for Google Application Engine Integration

The ability to integrate the Windward Engine into Google’s cloud computing platform for developing and hosting web applications dubbed Google Applications Engine (GAE).

Additional Refinement for HTML Output

  • Improved indentation for ordered and unordered lists
  • Better handling of template header and footer images
  • Better handling for background images and colors

Redesigned PDF Output Support

This new  integration will allow for processing of complex scripts and bi-directional  text such as Arabic.  Your PDF output  will be much tighter and more closely match your template, and we’ll be able  to respond rapidly to PDF requests and fixes.

PowerPoint Support

Includes support for new ForEach and slide break handling, table header row repeat across slide breaks, and native Microsoft support for charts and images.

Tags are Color Coded

Tags are color coded in the template by type, making it easy to visually identify them.

Increased Performance

Version 13’s core code has been reworked and optimized to offer a reduced memory footprint, faster PDF generation and full documentation of supported features and limitations in the specifications for DOCX, XLSX and PPTX.

Advanced Image Properties

Documents can include advanced Word image properties such as shadows, borders, and styles.

Improved HTML Output

Windward has updated HTML output to reflect changing HTML standards.

Version 13 New Data Sources

Windward now works with a slew of new datasources: MongoDB, JSON, Cassandra, OData, Salesforce.com

Generate Code

Designer (fka AutoTag) Generate Code tool allows you to open an existing template and, with a click of a button, automatically create a window with the code needed to run your current template with all data sources and variables in your .NET or Java project. The process is quick, shortens delivery time and helps alleviate any bumps in the road.

Pivot Tables Adjusted in Output

Any pivot tables in the template are carried over to XLSX output. The ranges in the pivot ranges are adjusted to match the generated output. So your final XLSX will be pivot tables set as expected in the generated file.

Imported Template Can be Set to Match the Parent Styles

In an imported sub-template, if its properties for a style (ex. Normal) differ from the parent template's properties for the style, the use in the sub-template can be set to either use the properties in the sub-template, ot the properties in the parent.

Tags can be Placed in Text Boxes

Tags can be placed in text boxes. Including linked text boxes. This gives you the ability to set the text in a textbox from your data.

Tags can be Placed in Shapes & Smart Art

Tags can be placed in shapes & smart art. This gives you the ability to set the text in a shape from your data.

HTML Output Supports Embedded Images

When generating HTML output, the engine can either write bitmaps as distinct files the generate HTML references, or it can embed the images in the HTML providing a single file for the output.

Footnotes & Endnotes can Have Tags

You can place tags in pretty much any part of a template, including in footnotes & endnotes.

Document Locking Supported in DOCX & XLSX

Any parts of a DOCX or XLSX (PowerPoint does not support this) file that are locked in the template, will be locked the same in the output.

Specify Font Substitution

If a font used in the template does not exist on the server generating a report, the font to substitute can be specified.
In addition, if a glyph to be rendered does not exist in the font specified, you can specify the replacement font. This can be set distinctly for European, Bi-Directional, and Far East fonts.

Process Multiple Datasources Simultaneously

When Windward is merging the data into a template, it process the template handling each tag in order, and the tags can pull from different datasources. This allows the select in a tag to use data from other datasources in the select.

David Thielen

President/CEO at Windward Studios

From his early years as a Senior Developer at Microsoft, to legendary designer of the popular Enemy Nations strategy game, to reporting and document generation guru, Dave has never lost his passion for building superb software and teams.

david@windward.nethttps://www.linkedin.com/in/davethielen/

For over 10 years, Windward has lead the industry with our world-class document generation platform that creates visually stunning, data-powered documents designed exactly the way users want and are created in a fraction of the time and cost compared to existing solutions. Proudly located in Boulder, Colorado, Windward Studios is the premier solution for developers and business users adding reporting and document generation capabilities to their applications in over 70 countries around the world.

Contact

Got questions about reporting and document generation? We've got answers—let's connect!
Send a note