v147 · proposed IWA API · member reference

WebPrintJob.onjobstatechange

Event handler for job progress or state updates. Prefer addEventListener() when more than one listener may be needed.

Proposal and implementation differ from the old overviewChromeStatus currently records this API as Proposed, not shipped. This reference follows the current WICG IDL and Chromium source; test in the intended IWA configuration and feature-detect rather than relying on the v147 label.

Syntax

job.onjobstatechange = (event) => {
  console.log(job.attributes());
};
// event type: "jobstatechange"

Inputs

Assign an event handler or register job.addEventListener("jobstatechange", listener). The event has no specified custom payload; obtain current data with attributes().

Outputs

The user agent must fire when jobState or jobPagesCompleted changes. Chromium suppresses an update where neither changed.

Errors

There is no event error channel. Submission failures reject before a job object exists; terminal canceled and aborted are states, not exceptions.

Context and permission

The IDL requires a secure, isolated context. The specification also defines the web-printing Permissions Policy with default allowlist self; Chromium additionally checks an isolated context and cross-origin isolation before getPrinters(). The current proposal requires express, origin-specific consent triggered by enumeration. The exact chooser scope, persistence, and whether a later operation prompts again remain user-agent UX, not a settled web contract.

Lifecycle, cancellation, and cleanup

Register promptly after submission. The spec does not promise replay of earlier events. On a terminal state, remove listeners if the job object remains reachable; Chromium has no further updates after terminal state.

Examples

function waitForTerminalState(job) {
  return new Promise((resolve) => {
    const onChange = () => {
      const snapshot = job.attributes();
      if (["completed", "canceled", "aborted"].includes(snapshot.jobState)) {
        job.removeEventListener("jobstatechange", onChange);
        resolve(snapshot);
      }
    };
    job.addEventListener("jobstatechange", onChange);
    onChange();
  });
}

Browser compatibility

Current public compatibility evidence (checked 2026-07-26)
Runtime	Status	Evidence
Chrome (general)	Proposed and not released. ChromeStatus lists I2S desktop target 147, which is not release proof. Do not infer general desktop Chrome support.	ChromeStatus
Current Chromium service	Implemented only when built with `IS_CHROMEOS && USE_CUPS`; otherwise `getPrinters()` has no service and throws `SecurityError`.	Chromium manager implementation
Android / mobile	ChromeStatus Android is `null`; no public mobile release exists. The current ChromeOS+CUPS-only service path does not expose the service on Android.	ChromeStatus; implementation guard
Firefox	No signal; no BCD member record found.	ChromeStatus position; BCD API data
Safari	No signal; no BCD member record found.	ChromeStatus position; BCD API data
webstatus.dev	No feature entry found for this query; this is not proof of absence from browsers.	webstatus query

Security and privacy

Printer names, IDs, capabilities and state can fingerprint a device and reveal printing activity. A compromised IWA could create unwanted jobs or denial of service. Minimize enumeration and polling, do not expose attributes to untrusted content, validate documents before submitting, and offer an app-level confirmation/audit trail. The spec requires isolation and consent; it does not make printer information non-sensitive.