Thursday, 18 February 2016

ColdFusion 2016: half-arse`d-ness from Adobe on a potentially handy feature

G'day:
This'll be a lot quicker than I anticipated, given Adobe haven't actually bothered to implement most of the given feature.

Back in the ColdFusion 10 era, I raised 3597432 ("replaceWithCallback()"). The idea here was to add an option to replace() to make it behave more like JavaScript's String.prototype.replace(), in that it can take a callback to perform the replacement operation. Quite often a replacement operation might be mroe than a simple swap-out for one value for another, beyond the scope that regex operations can facilitate it. So using a callback allows one to handle the replacement anyway one likes.

Here's an example of the JavaScript version:

source = "this is a string from which to exchange some matches using a callback to perform the exchange";
match = new RegExp("exchange", "g");
replacement = "replace";

result = source.replace(match, function(match, index, source){
    return replacement;
});

console.log(result);

Which yields:

C:\src\CF12\strings\replaceWithCallback>node replace.js
this is a string from which to replace some matches using a callback to perform the replace

C:\src\CF12\strings\replaceWithCallback>

Note how this just swaps out all the instances of "exchange" for "replace". This is a daft usage of a callback, but you get the general idea.

So ColdFusion 2016 implements this:

source = "this is a string from which to exchange some matches using a callback to perform the exchange";
match = "exchange";
replacement = "replace";

result = source.replace(match, function(match, index, source){
    return replacement;
}, "ALL");

writeDump([
    source=source,
    match=match,
    replacement=replacement,
    result = result
]);

Result:



So that's cool. It works.

But do you know what's not cool?

They only implemented it on replace(). They did not implement it on replaceNoCase(). Nor reReplace(). nor reReplaceNoCase().

Sigh. Useless. Just useless.

So really... in that they only added it to one of four congruent functions, this represents making CFML (haha, I initially typoed that as "FML"... somewhat fittingly perhaps) just that little bit worse, rather than that little bit better.

Righto.

--
Adam
at