Export all built-in filters as functions for direct use

[Nowaker]

I must implement date_to_xmlschema from Jekyll and I'd like to call

liquidjs/src/builtin/filters/date.ts

Line 7 in 58d0389

export function date (this: FilterImpl, v: string | Date, arg: string) {

in my filter directly. This is however not possible because these filters aren't exported by the module.

[Nowaker]

And being able to use classes like LiquidTime or TimezoneDate would be helpful too. It's essential for any type of modding Liquidjs.

[harttle]

I think this makes sense, I can help include this in next version.

[github-actions]

🎉 This issue has been resolved in version 9.35.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[ghost]

How do you call the builtin filters? I'm trying to use default inside of my own filter, so I don't have to do all the same work that default already does. I want to make a filter that only prepends to the value if there is a value...

tplEngine.registerFilter("pre", function pre(value: any, ...args: any[]) {
  const defaultValue = filters["default"] as FilterHandler;
  const valueToPrefix = defaultValue(value, false);
});

I get a TS error for defaultValue saying that The 'this' context of type 'void' is not assignable to method's 'this' of type 'FilterImpl'.ts(2684), so I must be doing something wrong. Where is the impl to call it from?

[ghost]

OK, I think I figured it out now. This is working:

import type { FilterHandler } from "liquidjs/dist/src/template/filter-impl-options";
import { Liquid, filters } from "liquidjs";


/** Built-in filter, use in custom filter `append.call(this,...args)` */
const append = filters["append"] as FilterHandler;
/** Built-in filter, use in custom filter `getDefault.call(this,...args)` */
const getDefault = filters["default"] as FilterHandler;
/** Built-in filter, use in custom filter `prepend.call(this,...args)` */
const prepend = filters["prepend"] as FilterHandler;

tplEngine.registerFilter(
  "post",
  /** An "append" filter that only appends when there is a value. */
  function post(value: any, postfix: string) {
    value = getDefault.call(this, value, false);
    if (value === false) return "";
    return append.call(this, value, postfix);
  },
);
tplEngine.registerFilter(
  "pre",
  /** A "prepend" filter that only prepends when there is a value. */
  function pre(value: any, prefix: string) {
    value = getDefault.call(this, value, false);
    if (value === false) return "";
    return prepend.call(this, value, prefix);
  },
);

I also used the following tactic to register a shorter alias to the default filter:

tplEngine.registerFilter("or", getDefault);

I am not sure if there is any difference between accessing the imported filters above or using tplEngine.filters.

[harttle]

You’re right. Use .call() or .apply() to pass a proper this.