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@dead-claudia
Created May 6, 2021 15:50
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patch userland implementation
export function patch(target, props) {
return m(Patch, {target, ...props})
}
const hasOwn = {}.hasOwnProperty
const isEventKey = /^on(?!init|create|(?:before)?(?:update|remove)$)/
function Patch({attrs}) {
function handler(event) {
const onevent = attrs[`on${event.type}`]
let result
if (typeof onevent === "function") {
result = onevent.call(event.currentTarget, event)
} else if (typeof onevent.handleEvent === "function") {
onevent.handleEvent(event)
}
if (event.redraw !== false) {
m.redraw()
}
if (result === false) {
event.preventDefault()
event.stopPropagation()
}
}
function oncreate({attrs}) {
const target = attrs.target
for (const key of Object.keys(attrs)) {
if (isEventKey.test(key)) {
target.addEventListener(key, handler, false)
}
}
}
function onremove({attrs}) {
const target = attrs.target
for (const key of Object.keys(attrs)) {
if (isEventKey.test(key)) {
target.removeEventListener(key, handler, false)
}
}
}
return {
onbeforeupdate(vnode, old) {
attrs = vnode.attrs
if (vnode.attrs.target !== old.attrs.target) {
onremove(old)
oncreate(vnode)
} else {
const target = vnode.attrs.target
for (const key of Object.keys(vnode.attrs)) {
if (
isEventKey.test(key) &&
!hasOwn.call(old.attrs, key)
) {
target.addEventListener(key, handler, false)
}
}
for (const key of Object.keys(old.attrs)) {
if (
isEventKey.test(key) &&
!hasOwn.call(vnode.attrs, key)
) {
target.removeEventListener(key, handler, false)
}
}
}
// Nothing's actually rendered. Let's not waste our time with it.
return false
},
view() {},
oncreate,
onremove,
}
}
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