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Issue 17.6 ('Xojo in Cologne')
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FEATURE

Designing For Error Tolerance

Making error-tolerance part of the MVC paradigm

Issue: 17.6 (November/December 2019)
Author: JC Cruz
Author Bio: JC is a freelance writer based in British Columbia. He is a regular contributor to MacTech Magazine and Dr Dobb's Journal. Away from the writing pile, JC spends quality time with his nephew, as a proper uncle should.
Article Description: n>No description availabl
Article Length (in bytes): 45,648
Starting Page Number: r>
Article Number: 17607
Resource File(s):

Download Icon project17607.zip Updated: 2019-11-01 12:16:07

Related Web Link(s):

r>http://en.wikipedia.org/wiki/Defensive_programming
http://en.wikipedia.org/wiki/Design
http://en.wikipedia.org/wiki/Error
http://en.wikipedia.org/wiki/Exception_handling
http://en.wikipedia.org/wiki/Exception

Excerpt of article text...

Errors happen because developers and users are human. The wrong data is entered, the wrong task done. A routine gets stuck in an endless loop. A crash takes place for no obvious reason.

In general, errors make for a poor user experience. This is why error tolerance is an important part of software design.

This article describes how I make my demo project error-tolerant. I explain the differences between errors and exceptions and ways to handle them. I design a new controller, one that receives and records errors and exceptions. And I modify key controllers and views, making them able to detect and react to errors.

The revised version of the FooHealth demo project (Mk2.2) is available from the magazine's website. Readers must have a working knowledge of Xojo and object-oriented design.

The Concept of Error Tolerance

For a software product to be error-tolerant, it must react correctly and predictably to an unexpected error. The reaction can be as simple as rejecting incorrect entries or as complex as protecting user data. An error-tolerant product can give its users a less frustrating, more satisfying experience.

...End of Excerpt. Please purchase the magazine to read the full article.