ProgressEvent

The ProgressEvent インターフェースは (XMLHttpRequest、または <img>, <audio>, <video>, <style> ,<link>のような基本的なリソースのロードなどの)のようなHTTPリクエストイベントの基本的なプロセスの進捗の進み具合を表示します。

コンストラクタ

ProgressEvent()

Creates a ProgressEvent event with the given parameters.

Properties

Also inherits properties from its parent Event.

ProgressEvent.lengthComputable 読取専用

Is a Boolean flag indicating if the total work to be done, and the amount of work already done, by the underlying process is calculable. In other words, it tells if the progress is measurable or not.

ProgressEvent.loaded 読取専用

Is an unsigned long long representing the amount of work already performed by the underlying process. The ratio of work done can be calculated with the property and ProgressEvent.total. When downloading a resource using HTTP, this only represent the part of the content itself, not headers and other overhead.

ProgressEvent.total 読取専用

Is an unsigned long long representing the total amount of work that the underlying process is in the progress of performing. When downloading a resource using HTTP, this only represent the content itself, not headers and other overhead.

メソッド

Also inherits methods from its parent Event.

ProgressEvent.initProgressEvent()

Initializes a ProgressEvent created using the deprecated Document.createEvent("ProgressEvent") method.

例

The following example adds a ProgressEvent to a new XMLHTTPRequest and uses it to display the status of the request.

  var progressBar = document.getElementById("p"),
      client = new XMLHttpRequest()
  client.open("GET", "magical-unicorns")
  client.onprogress = function(pe) {
    if(pe.lengthComputable) {
      progressBar.max = pe.total
      progressBar.value = pe.loaded
    }
  }
  client.onloadend = function(pe) {
    progressBar.value = pe.loaded
  }
  client.send()

仕様書

ブラウザ互換性

[1] This feature was implemented in Chrome 1.0, but removed in Chrome 17.0.

[2] This feature was implemented in Gecko 1.9.1 (Firefox 3.5 / Thunderbird 3.0 / SeaMonkey 2.0), but removed in Gecko 22 (Firefox 22 / Thunderbird 22 / SeaMonkey 2.19).

[3] This feature was removed at some point.

[4] This feature was removed in Opera 15.0.

See also

• The Event base interface.