Angular/Typescript RegExp enum - regex

Question

Looking to create an enum for some regex to store in my application to allow for code reuse.
Eg:
export enum Regex {
ONE_DANK_REGEX = /^[dank]+$/g,
FIVE_OUT_OF_SEVEN = /^[meme]{5,7}$/g
}
But:
By not using string literals, I get the TS90010 error: Type RegExpis not assignable to type Regex.
By using string literals, I can't use these in a pattern attribute on my inputs
Eg.
<input ngModel="..." pattern="{{FIVE_OUT_OF_SEVEN}}" .../>
Is this the right way of going about doing this?

Answer 1

You cannot assign a RegExp to an enum, an enum can either be numeric or string-based.
So when it comes to storing the RegExp you have two options:
Option A - store the RegExp as string in an enum
enum RegExpEnum {
ONE_DANK_REGEX = "^[dank]+$",
FIVE_OUT_OF_SEVEN = "^[meme]{5,7}$"
}
Option B - store the RegExp in a class/variable
class RegexClass {
public static readonly ONE_DANK_REGEX = /^[dank]+$/g;
public static readonly FIVE_OUT_OF_SEVEN = /^[meme]{5,7}$/g;
}
In both ways you need to get a reference to the containing enum or class in your component. Which can be achieved by assigning it to a local variable.
#Component({ ... })
public class MyComponent {
availableRegex = RegExpEnum; // or RegexClass
}
Then you can access it in the html part of your component.
<input [(ngModel)]="name" [pattern]="availableRegex.ONE_DANK_REGEX"/>
DEMO

Answer 2

Enum will support only strings and Number.
If you wanted to store regular expressions, you need to use static class
export class RegularExpression
{
public static ALPHA_CHARACTERS: RegExp = /([^A-Za-z])+/g;
}
Usage
'Your_* Name'.replace(RegularExpression.ALPHA_CHARACTERS, '');

Answer 3

Prefer the option A mentioned on the currently accepted answer and use it as below the code:
export enum Regex {
ONE_DANK_REGEX = "^[dank]+$",
FIVE_OUT_OF_SEVEN = "^[meme]{5,7}$",
}
public readonly regOne = new RegExp(Regex.ONE_DANK_REGEX, "g");
This gives some flexibility when create the regular expression object.