Function naming: ActionIfCondition()

Question

I often need to use a function which performs and action X is condition Y is set. What is the best way to name such a function?

I don't want to repeat if statements, since they could be complex.

For instance, if I want to trim a string if a property is set, function could be named:

• void TrimIfOptionSet(string) -- too unwieldy, especially if condition is complex
• bool TryTrim(string) -- does not mention an external condition, I'd expect it to only take the argument into account.
• void ConditionalTrim(string) -- bit verbose

Are there any conventions for this situation in C#/.Net, or any similar language?

Answer 1

Try something like:

if(IsComplexCondition(complexData))
{
    DoThing(otherData);
}

You generally don't want to couple the condition with the operation because you're making a single function capture too much semantic information at that point. It's "doing more than one thing." Instead, if you have a complex condition, capture that condition in a function to encapsulate it.

If you're referring to a much more common situation, such as parameter validation at the top of functions, consider something like fluent parameter validation. If you're not doing something like parameter validation, then I might question why it's at the top of every function and not captured in a common location or performed once at a system boundary.

I don't think that there is a good answer for naming the general ActionIfSomething() case simply because it's not generally a good solution to a problem. I'd probably just say make the function call Action() and document it, perhaps in <remarks>, to only perform the action when Something is true. If the Action belongs with the condition in the function, then it only makes sense in the context of that condition, so re-specifying it in the function name is redundant.

Answer 2

Could this be solved through the use of accessors?

public class MyObject
{
     private string _content = string.Empty;

     public bool Trim { get; set; }

     public string Content
     {
          get
          {
               return this.Trim ? _content.Trim() : _content;
          }
          internal set
          {
               if (string.IsNullOrEmpty(value))
                    _content = string.Empty; 
               else
                    _content = value;
          }
     }
}

This will take the action determined by the Trim boolean whenever the Content is accessed. I've protected the set accessor, since it might be somewhat ambigious what happens when the value of Content is set while Trim is true, and checked for the special case of trying to set the content to null. Good documentation should cover these cases.

Answer 3

Given the constraints, I'd pick TrimIfOptionSet or TrimIfNeeded.

• TryTrim feels like it'll always run a trim operation (in a try block), which isn't the same as running it only if needed
• ConditionalTrim is too long -- the reader's eyes stay on "conditional" and never get to "trim"