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Code Snippet Of the Day (CodeSOD) features interesting and usually incorrect code snippets taken from actual production code in a commercial and/or open source software projects.
“Throw typed exceptions,” is generically good advice in a strongly typed language, like Java. It shouldn’t be followed thoughtlessly, but it’s a good rule of thumb. Some people may need a little more on the point, though.
Alexander L sends us this code:
Chris M works for a “solutions provider”. Mostly, this means taking an off-the-shelf product from Microsoft or Oracle or SAP and customizing it to fit a client’s specific needs. Since many of these clients have in-house developers, the handover usually involves training those developers up on the care and maintenance of the system.
Then, a year or two later, the client comes back, complaining about the system. “It’s broken,” or “performance is terrible,” or “we need a new feature”. Chris then goes back out to their office, and starts taking a look at what has happened to the code in his absence.
I’ve had to write a few domain-specific-languages in the past. As per Remy’s Law of Requirements Gathering, it’s been mostly because the users needed an Excel-like formula language. The danger of DSLs, of course, is that they’re often YAGNI in the extreme, or at least a sign that you don’t really understand your problem.
XML, coupled with schemas, is a tool for building data-focused DSLs. If you have some complex structure, you can convert each of its features into an XML attribute. For example, if you had a grammar that looked something like this:
Just last week, I was teaching a group of back-end developers how to use Angular to develop front ends. One question that came up, which did suprise me a bit, was how to deal with race conditions and concurrency in JavaScript.
I’m glad they asked, because it’s a good question that never occurred to me. The JavaScript runtime, of course, is single-threaded. You might use Web Workers to get multiple threads, but they use an Actor model, so there’s no shared state, and thus no need for any sort of locking.
Anonymous sends us this little blob of code, which is mildly embarassing on its own:
Aug 17 static StringBuilder vsb = new StringBuilder();
internal static string IsValidUrl(string value)
{
if (value == null)
{
return "\"\"";
}
vsb.Length= 0;
vsb.Append("@\"");
for (int i=0; i<value.Length; i++)
{
if (value[i] == '\"')
vsb.Append("\"\"");
else
vsb.Append(value[i]);
}
vsb.Append("\"");
return vsb.ToString();
}_(14597321320).jpg)
Paul R. shows us a classic example of the sort of case statement that maybe, you know, never should've been implemented as a case statement:
Ah, consumer products. Regardless of what the product in question is, therre’s a certain amount of “design” that goes into the device. Not design which might make the product more user-friendly, or useful, or in any way better. No, “design”, which means it looks nicer on the shelf at Target, or Best Buy, or has a better image on its Amazon listing. The manufacturer wants you to buy it, but they don’t really care if you use it.
This thinking extends to any software that may be on the device. This is obviously true if it’s your basic Internet of Garbage device, but it’s often true of something we depend on far more: consumer grade routers.
Matthew H was given a pretty basic task: save some data as a blob. This task was made more complicated by their boss’s core philosophy, though.
Never. Bother. The. Customer..
LINQ brings functional programming and loads of syntactic sugar to .NET languages. It’s a nice feature, although as James points out, it helps if your fellow developers have even the slightest clue about what they’re doing.
// some validation checking
var retrieveDocIdList = this.storedDocumentManager.GetAllForClientNotRetrieved(client.Id).Select(x => x.Id.ToString(CultureInfo.InvariantCulture)).ToList();
retrieveDocIdList.ForEach(id => {
var storedDoc = this.storedDocumentManager.Get(int.Parse(id))
// do some other stuff with the doc
});