Question

I am using HighCharts and am generating script from C# and there’s an unfortunate thing where they use inline functions for formatters and events. Unfortunately, I can’t output JSON like that from any serializer I know of. In other words, they want something like this:

"labels":{"formatter": function() { return Highcharts.numberFormat(this.value, 0); }}

And with my serializers available to me, I can only get here:

"labels":{"formatter":"function() { return Highcharts.numberFormat(this.value, 0); }"}

These are used for click events as well as formatters, and I absolutely need them.

So I’m thinking regex, but it’s been years and years and also I was never a regex wizard.

What kind of Regex replace can I use on the final serialized string to replace any quoted value that starts with function() with the unquoted version of itself? Also, the function itself may have ” in it, in which case the quoted string might have \” in it, which would need to also be replaced back down to “.

I’m assuming I can use a variant of the first answer here:

Finding quoted strings with escaped quotes in C# using a regular expression

but I can’t seem to make it happen. Please help me for the love of god.

I’ve put more sweat into this, and I’ve come up with

    serialized = Regex.Replace(serialized, @"""function\(\)[^""\\]*(?:\\.[^""\\]*)*""", "function()$1");

However, my end result is always:

formatter:function()$1

This tells me I’m matching the proper stuff, but my capture isn’t working right. Now I feel like I’m probably being an idiot with some C# specific regex situation.

Update: Yes, I was being an idiot. I didn’t have a capture around what I really wanted.

   `enter code here` serialized = Regex.Replace(serialized, @"""function\(\)([^""\\]*(?:\\.[^""\\]*)*)""", "function()$1");

that gets my match, but in a case like this:

"formatter":"function() { alert(\"hi!\"); return Highcharts.numberFormat(this.value, 0); }"

it returns:

"formatter":function() { alert(\"hi!\"); return Highcharts.numberFormat(this.value, 0); }

and I need to get those nasty backslashes out of there. Now I think I’m truly stuck.

Answer 1

    string serialized = JsonSerializer.Serialize(chartDefinition);
    serialized = Regex.Replace(serialized, @"""function\(\)([^""\\]*(?:\\.[^""\\]*)*)""", "function()$1").Replace("\\\"", "\"");