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The ProgressEvent
interface represents events measuring progress of an underlying process, like an HTTP request (for an XMLHttpRequest
, or the loading of the underlying resource of an <img>
, <audio>
, <video>
, <style>
or <link>
).
Constructor
ProgressEvent()
- Creates a
ProgressEvent
event with the given parameters.
Properties
Also inherits properties from its parent Event
.
ProgressEvent.lengthComputable
Read only- 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
Read only- 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 andProgressEvent.total
. When downloading a resource using HTTP, this only represent the part of the content itself, not headers and other overhead. ProgressEvent.total
Read only- 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.
Methods
Also inherits methods from its parent Event
.
ProgressEvent.initProgressEvent()
- Initializes a
ProgressEvent
created using the deprecatedDocument.createEvent("ProgressEvent")
method.
Examples
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()
Specifications
Specification | Status | Comment |
---|---|---|
Progress Events The definition of 'ProgressEvent' in that specification. |
Candidate Recommendation | Initial definition. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 1.0 | 3.5 (1.9.1) | 10.0 | (Yes) | (Yes) |
initProgressEvent() |
No support[1] | No support[2] | 10.0 | No support[4] | No support[3] |
Feature | Android | Android Webview | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | 1.0 (1.9.1) | 10.0 | (Yes) | (Yes) | (Yes) |
initProgressEvent() |
No support[3] | No support | No support[2] | 10.0 | No support[4] | No support[3] | No support |
[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.