package.src.modules.dataset.ts Maven / Gradle / Ivy

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import { VNode, VNodeData } from "../vnode";
import { Module } from "./module";

export type Dataset = Record;

const CAPS_REGEX = /[A-Z]/g;

function updateDataset(oldVnode: VNode, vnode: VNode): void {
  const elm: HTMLElement = vnode.elm as HTMLElement;
  let oldDataset = (oldVnode.data as VNodeData).dataset;
  let dataset = (vnode.data as VNodeData).dataset;
  let key: string;

  if (!oldDataset && !dataset) return;
  if (oldDataset === dataset) return;
  oldDataset = oldDataset || {};
  dataset = dataset || {};
  const d = elm.dataset;

  for (key in oldDataset) {
    if (!dataset[key]) {
      if (d) {
        if (key in d) {
          delete d[key];
        }
      } else {
        elm.removeAttribute(
          "data-" + key.replace(CAPS_REGEX, "-$&").toLowerCase()
        );
      }
    }
  }
  for (key in dataset) {
    if (oldDataset[key] !== dataset[key]) {
      if (d) {
        d[key] = dataset[key];
      } else {
        elm.setAttribute(
          "data-" + key.replace(CAPS_REGEX, "-$&").toLowerCase(),
          dataset[key]
        );
      }
    }
  }
}

export const datasetModule: Module = {
  create: updateDataset,
  update: updateDataset,
};