If the current context is a worker
, the workerStart
property returns a timestamp
immediately before the worker that fetches the resource is started. If the context is not a worker (i.e. a browser context), this property returns zero.
This property is Read only .
Syntax
resource.workerStart;
Return value
If the current context is a worker
, returns the DOMHighResTimeStamp
immediately before the worker is started that fetches the resource; otherwise, the timestamp is zero.
Example
In the following example, the value of the *Start
and *End
properties of all "resource
" type
events are logged.
function print_PerformanceEntries() { // Use getEntriesByType() to just get the "resource" events var p = performance.getEntriesByType("resource"); for (var i=0; i < p.length; i++) { print_start_and_end_properties(p[i]); } } function print_start_and_end_properties(perfEntry) { // Print timestamps of the PerformanceEntry *start and *end properties properties = ["connectStart", "connectEnd", "domainLookupStart", "domainLookupEnd", "fetchStart", "redirectStart", "redirectEnd", "requestStart", "responseStart", "responseEnd", "secureConnectionStart", "workerStart"]; for (var i=0; i < properties.length; i++) { // check each property var supported = properties[i] in perfEntry; if (supported) { var value = perfEntry[properties[i]]; console.log("... " + properties[i] + " = " + value); } else { console.log("... " + properties[i] + " = NOT supported"); } } }
Specifications
Specification | Status | Comment |
---|---|---|
Resource Timing The definition of 'workerStart' in that specification. |
Editor's Draft | Initial definition. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support. | 43 | No support | No support | 32 | No support |
Feature | Android | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support. | 4.4 | No support | No support | No support | 32 | No support |