51 lines
1.1 KiB
JavaScript
51 lines
1.1 KiB
JavaScript
import progressbar from '../render/progressbar'
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import { noop } from '../util/core'
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const cache = {}
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/**
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* Simple ajax get
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* @param {string} url
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* @param {boolean} [hasBar=false] has progress bar
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* @return { then(resolve, reject), abort }
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*/
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export function get (url, hasBar = false) {
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const xhr = new XMLHttpRequest()
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const on = function () {
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xhr.addEventListener.apply(xhr, arguments)
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}
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if (cache[url]) {
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return { then: cb => cb(cache[url]), abort: noop }
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}
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xhr.open('GET', url)
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xhr.send()
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return {
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then: function (success, error = noop) {
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if (hasBar) {
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const id = setInterval(_ => progressbar({
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step: Math.floor(Math.random() * 5 + 1)
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}), 500)
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on('progress', progressbar)
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on('loadend', evt => {
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progressbar(evt)
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clearInterval(id)
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})
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}
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on('error', error)
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on('load', ({ target }) => {
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if (target.status >= 400) {
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error(target)
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} else {
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cache[url] = target.response
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success(target.response)
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}
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})
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},
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abort: _ => xhr.readyState !== 4 && xhr.abort()
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}
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}
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