1 files changed, 124 insertions, 0 deletions
diff --git a/src/js/helpers.js b/src/js/helpers.js
new file mode 100644
index 0000000..1152d24
--- /dev/null
+++ b/src/js/helpers.js
@@ -0,0 +1,124 @@
+// dom helper functions
+const throttle = require('lodash.throttle')
+export function qs (sel, parent = document.body) {
+  if (typeof parent === 'string') {
+    parent = document.querySelector(parent)
+  }
+  return parent.querySelector(sel)
+}
+
+export function elt (name, attr = {}, ...text) {
+  const node = document.createElement(name)
+  Object.keys(attr).forEach(k => {
+    node.setAttribute(k, attr[k])
+  })
+  text.forEach(t => {
+    if (typeof t === 'string') {
+      t = document.createTextNode(t)
+    }
+    node.appendChild(t)
+  })
+  return node
+}
+
+export function removeClass (dom, cls) {
+  if (typeof dom === 'string') {
+    dom = qs(dom)
+  }
+  dom.classList.remove(cls)
+  return dom
+}
+export function clearClass (dom, cls) {
+  if (typeof dom === 'string') {
+    dom = qs(dom)
+  }
+  dom.className = ''
+  return dom
+}
+export function addClass (dom, cls) {
+  if (typeof dom === 'string') {
+    dom = qs(dom)
+  }
+  dom.classList.add(cls)
+  return dom
+}
+export function toggleClass (dom, cls) {
+  if (typeof dom === 'string') {
+    dom = qs(dom)
+  }
+  dom.classList.toggle(cls)
+  return dom
+}
+export function hasClass (dom, cls) {
+  if (typeof dom === 'string') {
+    dom = qs(dom)
+  }
+  return dom.classList.contains(cls)
+}
+export function setStyle (dom, styles) {
+  if (typeof dom === 'string') {
+    dom = qs(dom)
+  }
+
+  Object.keys(styles).forEach(key => {
+    dom.style[key] = styles[key]
+  })
+}
+export function onEvent (event, cb, limit = 0, dom = document.body) {
+  if (typeof dom === 'string') {
+    dom = qs(dom)
+  }
+  if (limit > 0) {
+    dom.addEventListener(event, throttle(cb, limit))
+  } else {
+    dom.addEventListener(event, cb)
+  }
+}
+// mousemove and touchmove abstraction
+export function onPointerMove (cb, limit, dom = document.body) {
+  onEvent('mousemove', e => {
+    cb({ // eslint-disable-line
+      clientX: e.clientX,
+      clientY: e.clientY,
+      type: e.type
+    })
+  }, limit, dom)
+
+  onEvent('touchmove', e => {
+    cb({ // eslint-disable-line
+      clientX: e.touches[0].clientX,
+      clientY: e.touches[0].clientY,
+      type: e.type
+    })
+  }, limit, dom)
+}
+// local storage
+export const ls = {}
+ls.get = key => window.localStorage.getItem(key)
+
+ls.set = (key, value) => {
+  if (value === null || value === undefined) {
+    value = ''
+  } else if (typeof value !== 'string') {
+    value = JSON.stringify(value)
+  }
+  window.localStorage.setItem(key, value)
+}
+export function randomInt (min, max) {
+  min = Math.ceil(min)
+  max = Math.floor(max)
+  return Math.floor(Math.random() * (max - min)) + min
+}
+
+export function download (filename, text) {
+  const a = elt('a', {
+    href: 'data:text/plain;charset=utf-8,' + encodeURIComponent(text),
+    download: filename,
+    style: {
+      display: 'none'
+    }
+  })
+  document.body.appendChild(a)
+  a.click()
+  document.body.removeChild(a)
+}