Function fetch

fetch.js:526–633

(input, init)

}

export function fetch(input, init) {
  return new Promise(function(resolve, reject) {
    var request = new Request(input, init)

    if (request.signal && request.signal.aborted) {
      return reject(new DOMException('Aborted', 'AbortError'))
    }

    var xhr = new XMLHttpRequest()

    function abortXhr() {
      xhr.abort()
    }

    xhr.onload = function() {
      var options = {
        statusText: xhr.statusText,
        headers: parseHeaders(xhr.getAllResponseHeaders() || '')
      }
      // This check if specifically for when a user fetches a file locally from the file system
      // Only if the status is out of a normal range
      if (request.url.indexOf('file://') === 0 && (xhr.status < 200 || xhr.status > 599)) {
        options.status = 200;
      } else {
        options.status = xhr.status;
      }
      options.url = 'responseURL' in xhr ? xhr.responseURL : options.headers.get('X-Request-URL')
      var body = 'response' in xhr ? xhr.response : xhr.responseText
      setTimeout(function() {
        resolve(new Response(body, options))
      }, 0)
    }

    xhr.onerror = function() {
      setTimeout(function() {
        reject(new TypeError('Network request failed'))
      }, 0)
    }

    xhr.ontimeout = function() {
      setTimeout(function() {
        reject(new TypeError('Network request timed out'))
      }, 0)
    }

    xhr.onabort = function() {
      setTimeout(function() {
        reject(new DOMException('Aborted', 'AbortError'))
      }, 0)
    }

    function fixUrl(url) {
      try {
        return url === '' && g.location.href ? g.location.href : url
      } catch (e) {
        return url
      }
    }