anki/ts/html-filter/index.ts
2021-03-28 19:41:20 +10:00

57 lines
1.5 KiB
TypeScript

/* Copyright: Ankitects Pty Ltd and contributors
* License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html */
import {
filterElementBasic,
filterElementExtended,
filterElementInternal,
} from "./element";
import { filterNode } from "./node";
enum FilterMode {
Basic,
Extended,
Internal,
}
const filters: Record<FilterMode, (element: Element) => void> = {
[FilterMode.Basic]: filterElementBasic,
[FilterMode.Extended]: filterElementExtended,
[FilterMode.Internal]: filterElementInternal,
};
const whitespace = /[\n\t ]+/g;
function collapseWhitespace(value: string): string {
return value.replace(whitespace, " ");
}
function trim(value: string): string {
return value.trim();
}
const outputHTMLProcessors: Record<FilterMode, (outputHTML: string) => string> = {
[FilterMode.Basic]: (outputHTML: string): string =>
trim(collapseWhitespace(outputHTML)),
[FilterMode.Extended]: trim,
[FilterMode.Internal]: trim,
};
export function filterHTML(html: string, internal: boolean, extended: boolean): string {
const template = document.createElement("template");
template.innerHTML = html;
const mode = internal
? FilterMode.Internal
: extended
? FilterMode.Extended
: FilterMode.Basic;
const content = template.content;
const filter = filterNode(filters[mode]);
filter(content);
return outputHTMLProcessors[mode](template.innerHTML);
}