本文整理汇总了TypeScript中rxjs/operators.last函数的典型用法代码示例。如果您正苦于以下问题：TypeScript last函数的具体用法？TypeScript last怎么用？TypeScript last使用的例子？那么, 这里精选的函数代码示例或许可以为您提供帮助。
在下文中一共展示了last函数的8个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的TypeScript代码示例。
示例1: last3
last3() {
const source = from([1, 2, 3, 4, 5]);
// no values will pass given predicate, emit default
const exampleTwo = source.pipe(last(v => v > 5, -1));
// output: 'Nothing!'
const subscribeTwo = exampleTwo.subscribe(val => console.log(val));
}示例2: upload
upload(file: File) {
if (!file) { return; }
// COULD HAVE WRITTEN:
// return this.http.post('/upload/file', file, {
// reportProgress: true,
// observe: 'events'
// }).pipe(
// Create the request object that POSTs the file to an upload endpoint.
// The `reportProgress` option tells HttpClient to listen and return
// XHR progress events.
const req = new HttpRequest('POST', '/upload/file', file, {
reportProgress: true
});
// The `HttpClient.request` API produces a raw event stream
// which includes start (sent), progress, and response events.
return this.http.request(req).pipe(
map(event => this.getEventMessage(event, file)),
tap(message => this.showProgress(message)),
last(), // return last (completed) message to caller
catchError(this.handleError(file))
);
}示例3: rule
return input.pipe(mergeMap(inputTree => {
const result = rule(inputTree, context);
if (!result) {
return observableOf(inputTree);
} else if (typeof result == 'function') {
// This is considered a Rule, chain the rule and return its output.
return callRule(result, observableOf(inputTree), context);
} else if (isObservable(result)) {
// Only return the last Tree, and make sure it's a Tree.
return result.pipe(
defaultIfEmpty(),
last(),
tap(inner => {
if (!inner || !(TreeSymbol in inner)) {
throw new InvalidRuleResultException(inner);
}
}),
);
} else if (TreeSymbol in result) {
return observableOf(result);
} else {
return throwError(new InvalidRuleResultException(result));
}
}));示例4: rule
return input.pipe(mergeMap(inputTree => {
const result = rule(inputTree, context) as object;
if (result === undefined) {
return observableOf(inputTree);
} else if (TreeSymbol in result) {
return observableOf(result as Tree);
} else if (isObservable(result)) {
const obs = result as Observable<Tree>;
// Only return the last Tree, and make sure it's a Tree.
return obs.pipe(
last(),
tap(inner => {
if (!(TreeSymbol in inner)) {
throw new InvalidRuleResultException(inner);
}
}),
);
} else if (result === undefined) {
return observableOf(inputTree);
} else {
return throwError(new InvalidRuleResultException(result));
}
}));示例5: last1
last1() {
const source = from([1, 2, 3, 4, 5]);
// no arguments, emit last value
const example = source.pipe(last());
// output: "Last value: 5"
const subscribe = example.subscribe(val => console.log(`Last value: ${val}`));
}示例6: rule
return input.pipe(mergeMap(inputTree => {
const result = rule(inputTree, context) as object;
if (result === undefined) {
return observableOf(inputTree);
} else if (TreeSymbol in result) {
return observableOf(result as Tree);
} else if (typeof result == 'function') {
// This is considered a Rule, chain the rule and return its output.
return callRule(result, input, context);
} else if (isObservable(result)) {
const obs = result as Observable<Tree>;
// Only return the last Tree, and make sure it's a Tree.
return obs.pipe(
last(),
tap(inner => {
if (!(TreeSymbol in inner)) {
throw new InvalidRuleResultException(inner);
}
}),
);
} else if (result === undefined) {
return observableOf(inputTree);
} else {
return throwError(new InvalidRuleResultException(result));
}
}));示例7: asDiagram
asDiagram('last')('should take the last value of an observable', () => {
const e1 = hot('--a----b--c--|');
const e1subs = '^ !';
const expected = '-------------(c|)';
expectObservable(e1.pipe(last())).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
});示例8: it
it('should not return default value if an element is found', () => {
const e1 = hot('--a---^---b---c---d---|');
const e1subs = '^ !';
const expected = '----------------(d|)';
expectObservable(e1.pipe(last(null, 'x'))).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
});