How to programmatically double apostrophes in custom label translations?

Question

I have a custom label which contains a couple of parameters:

Hello, {0} the other param is {1}.

I wish to output this value in a Visualforce Page like so:

<apex:variable var="firstParam" value="THE_NAME"/>
<apex:variable var="secondParam" value="SECOND_PARAM"/>
<apex:outputText value="{!$Label.Whatever}">
    <apex:param value="{!firstParam}"/>
    <apex:param value="{!secondParam}"/>
</apex:outputText>

This of course outputs this:

Hello, THE_NAME, the other param is SECOND_PARAM.

So far so good. Now, if a translation for this custom label contains an apostrophe -- Hello, {0}, it's the second param: {1}. --, the string interpolation breaks like this:

Hello, THE_NAME, it's the second param: {1}.

I've discovered that I need to double the apostrophe -- Hello, {0}, it''s the second param: {1}. -- to make it work:

Hello, THE_NAME, it's the second param: SECOND_PARAM.

Escaping certain characters in strings is definitely a job for the computer rather than a translator.

What's the Visualforce way to have the single apostrophes in a custom label escaped?

I've tried to call a String replace method on the $Label.Whatever part, but this doesn't even compile. I also couldn't do String($Label.Whatever) to cast it, and I haven't been able to find any solution on the net.

Answer 1

Theoretically, you should be able to just do:

SUBSTITUTE($Label.Whatever, '\'', '\'\'')

However, I couldn't get SUBSTITUTE or CONTAINS to find the single quote characters until I created a new label with just that character.

SUBSTITUTE($Label.Whatever, $Label.SingleQuote, $Label.SingleQuote & $Label.SingleQuote)

---

The above approach is nice because it makes you independent of your controller. Additionally, you can write an Apex Class to help out as follows:

public class LabelServices
{
    public static String doubleSingleQuotes(String input)
    {
        return String.isBlank(input) ? input : input.replace('\'', '\'\'');
    }
}