open-consul/ui/packages/consul-ui/app/utils/dom/event-source/callable.js

95 lines
2.5 KiB
JavaScript

export const defaultRunner = function(target, configuration, isClosed) {
if (isClosed(target)) {
target.dispatchEvent({ type: 'close' });
return;
}
// TODO Consider wrapping this is a promise for none thenable returns
return target.source
.bind(target)(configuration, target)
.then(function(res) {
return defaultRunner(target, configuration, isClosed);
});
};
const errorEvent = function(e) {
return new ErrorEvent('error', {
error: e,
message: e.message,
});
};
const isClosed = function(target) {
switch (target.readyState) {
case 2: // CLOSED
case 3: // CLOSING
return true;
}
return false;
};
export default function(
EventTarget,
P = Promise,
run = defaultRunner,
createErrorEvent = errorEvent
) {
const CallableEventSource = function(source, configuration = {}) {
EventTarget.call(this);
this.readyState = 2;
this.source =
typeof source !== 'function'
? function(configuration, target) {
this.close();
return P.resolve();
}
: source;
this.readyState = 0; // CONNECTING
P.resolve()
.then(() => {
// if we are already closed, don't do anything
if (this.readyState > 1) {
return;
}
this.readyState = 1; // open
// the connection _was just_ opened
this.dispatchEvent({ type: 'open' });
return run(this, configuration, isClosed);
})
.catch(e => {
this.dispatchEvent(createErrorEvent(e));
// close after the dispatch so we can tell if it was an error whilst closed or not
// but make sure its before the promise tick
this.readyState = 2; // CLOSE
this.dispatchEvent({ type: 'close', error: e });
})
.then(() => {
// This only gets called when the promise chain completely finishes
// so only when its completely closed.
this.readyState = 2; // CLOSE
});
};
CallableEventSource.prototype = Object.assign(
Object.create(EventTarget.prototype, {
constructor: {
value: CallableEventSource,
configurable: true,
writable: true,
},
}),
{
close: function() {
// additional readyState 3 = CLOSING
switch (this.readyState) {
case 0: // CONNECTING
case 2: // CLOSED
this.readyState = 2;
break;
default:
// OPEN
this.readyState = 3; // CLOSING
}
// non-standard
return this;
},
}
);
return CallableEventSource;
}