goog.labs.result Namespacegoog.labs.result.DeferredAdaptor ClassAn adaptor from Result to a Deferred, for use with existing Deferred chains. … more
goog.labs.result.Result InterfaceA Result object represents a value returned by an asynchronous operation at some point in the future (e.g. a network fetch). This is akin to a 'Promise' or a 'Future' in other languages and frameworks. @interface … more
goog.labs.result.SimpleResult ClassA SimpleResult object is a basic implementation of the goog.labs.result.Result interface. This could be subclassed(e.g. XHRResult) or instantiated and returned by another class as a form of result. The caller receiving the result could then attach handlers to be called when the result is resolved(success or error). … more
.chain(result, actionCallback)The chain function aids in chaining of asynchronous Results. This provides a convenience for use cases where asynchronous operations must happen serially i.e. subsequent asynchronous operations are dependent on data returned by prior asynchronous operations. It accepts a result and an action callback as arguments and returns a result. The action callback is called when the first result succeeds and is supposed to return a second result. The returned result is resolved when one of both of the results resolve (depending on their success or failure.) The state and value of the returned result in the various cases is documented below: First Result State: Second Result State: Returned Result State: SUCCESS SUCCESS SUCCESS SUCCESS ERROR ERROR ERROR Not created ERROR The value of the returned result, in the case both results succeed, is the value of the second result (the result returned by the action callback.) Example:
var testDataResult = xhr.get('testdata/xhr_test_text.data');
// Chain this result to perform another asynchronous operation when this
// Result is resolved.
var chainedResult = goog.labs.result.chain(testDataResult,
function(testDataResult) {
// The result value of testDataResult is the URL for JSON data.
var jsonDataUrl = testDataResult.getValue();
// Create a new Result object when the original result is resolved.
var jsonResult = xhr.getJson(jsonDataUrl);
// Return the newly created Result.
return jsonResult;
});
// The chained result resolves to success when both results resolve to
// success.
goog.labs.result.waitOnSuccess(chainedResult, function(result) {
// At this point, both results have succeeded and we can use the JSON
// data returned by the second asynchronous call.
var jsonData = result.getValue();
assertEquals('ok', jsonData['stat']);
});
// Attach the error handler to be called when either Result fails.
goog.labs.result.waitOnError(chainedResult, function(result) {
alert('chained result failed!');
});
result {!goog.labs.result.Result}
actionCallback {!function(!goog.labs.result.Result):!goog.labs.result.Result}
goog.labs.result.Result}
.combine(var_args)Returns a result that waits on all given results to resolve. Once all have resolved, the returned result will succeed (and never error). Example:
var result1 = xhr.get('testdata/xhr_test_text.data');
// Get a second independent Result.
var result2 = xhr.getJson('testdata/xhr_test_json.data');
// Create a Result that resolves when both prior results resolve.
var combinedResult = goog.labs.result.combine(result1, result2);
// Process data after resolution of both results.
goog.labs.result.waitOnSuccess(combinedResult, function(results) {
goog.array.forEach(results, function(result) {
alert(result.getState());
});
});
var_args {...!goog.labs.result.Result}
goog.labs.result.Result}
.combineOnSuccess(var_args)Returns a result that waits on all given results to resolve. Once all have resolved, the returned result will succeed if and only if all given results succeeded. Otherwise it will error. Example:
var result1 = xhr.get('testdata/xhr_test_text.data');
// Get a second independent Result.
var result2 = xhr.getJson('testdata/xhr_test_json.data');
// Create a Result that resolves when both prior results resolve.
var combinedResult = goog.labs.result.combineOnSuccess(result1, result2);
// Process data after successful resolution of both results.
goog.labs.result.waitOnSuccess(combinedResult, function(results) {
var textData = results[0].getValue();
var jsonData = results[1].getValue();
assertEquals('Just some data.', textData);
assertEquals('ok', jsonData['stat']);
});
// Handle errors when either or both results failed.
goog.labs.result.waitOnError(combinedResult, function(combined) {
var results = combined.getError();
if (results[0].getState() == goog.labs.result.Result.State.ERROR) {
alert('result1 failed');
}
if (results[1].getState() == goog.labs.result.Result.State.ERROR) {
alert('result2 failed');
}
});
var_args {...!goog.labs.result.Result}
goog.labs.result.Result}
.transform(result, transformer)Given a result and a transform function, returns a new result whose value, on success, will be the value of the given result after having been passed through the transform function. If the given result is an error, the returned result is also an error and the transform will not be called. Example:
var result = xhr.getJson('testdata/xhr_test_json.data');
// Transform contents of returned data using 'processJson' and create a
// transformed result to use returned JSON.
var transformedResult = goog.labs.result.transform(result, processJson);
// Attach success and failure handlers to the tranformed result.
goog.labs.result.waitOnSuccess(transformedResult, function(result) {
var jsonData = result.getValue();
assertEquals('ok', jsonData['stat']);
});
goog.labs.result.waitOnError(transformedResult, function(error) {
// Failed getJson call
});
result {!goog.labs.result.Result}
transformer {!Function}
goog.labs.result.Result}
.wait(result, handler, opt_scope)Calls the handler on resolution of the result (success or failure). The handler is passed the result object as the only parameter. The call will be immediate if the result is no longer pending. Example:
var result = xhr.get('testdata/xhr_test_text.data');
// Wait for the result to be resolved and alert it's state.
goog.labs.result.wait(result, function(result) {
alert('State: ' + result.getState());
});
result {!goog.labs.result.Result}
handler {!function(!goog.labs.result.Result)}
opt_scope {!Object=}
.waitOnError(result, handler, opt_scope)Calls the handler if the result action errors. The result object is passed as the only parameter to the handler. The call will be immediate if the result object has already resolved to an error. Example:
var result = xhr.get('testdata/xhr_test_text.data');
// Attach a failure handler.
goog.labs.result.waitOnError(result, function(error) {
// Failed asynchronous call!
});
result {!goog.labs.result.Result}
handler {!function(!goog.labs.result.Result)}
opt_scope {!Object=}
.waitOnSuccess(result, handler, opt_scope)Calls the handler if the result succeeds. The result object is the only parameter passed to the handler. The call will be immediate if the result has already succeeded. Example:
var result = xhr.get('testdata/xhr_test_text.data');
// attach a success handler.
goog.labs.result.waitOnSuccess(result, function(result) {
var datavalue = result.getvalue();
alert('value : ' + datavalue);
});
result {!goog.labs.result.Result}
handler {!function(*, !goog.labs.result.Result)}
opt_scope {!Object=}