async-await

问题 If I drop into the VSCode debugger in some javascript code and call an asynchronous function with await it just returns a promise. How can I resolve the promise within the debugger so I can see what the result is? For example, if I define a function like so: const doAsyncThing = async () => { return new Promise((resolve) => { setTimeout(() => { resolve(5) }, 1000) }) } (async function() { const result = await doAsyncThing() console.log(`result is ${result}`) debugger })() Then this happens

问题 If I drop into the VSCode debugger in some javascript code and call an asynchronous function with await it just returns a promise. How can I resolve the promise within the debugger so I can see what the result is? For example, if I define a function like so: const doAsyncThing = async () => { return new Promise((resolve) => { setTimeout(() => { resolve(5) }, 1000) }) } (async function() { const result = await doAsyncThing() console.log(`result is ${result}`) debugger })() Then this happens

问题 I need to download a collection of images on button press. Currently, I'm doing it this way using react-native-fs : const downloadImageItem = async (imgUrl, id) => { const path = `${RNFS.DocumentDirectoryPath}/${id}.jpg`; RNFS.downloadFile({ fromUrl: imgUrl, toFile: path, }); }; const downloadImages = async (items) => { for (const item of items) { if (item.images.length) { await downloadImageItem(item.images[0].thumb, item.images[0].id); } } return Promise.resolve(); }; Calling the function

问题 I am trying to call an api during the blazor(client side) startup to load language translations into the ILocalizer. At the point I try and get the .Result from the get request blazor throws the error in the title. This can replicated by calling this method in the program.cs private static void CalApi() { try { HttpClient httpClient = new HttpClient(); httpClient.BaseAddress = new Uri(@"https://dummy.restapiexample.com/api/v1/employees"); string path = "ididcontent.json"; string response =

问题 I am trying to call an api during the blazor(client side) startup to load language translations into the ILocalizer. At the point I try and get the .Result from the get request blazor throws the error in the title. This can replicated by calling this method in the program.cs private static void CalApi() { try { HttpClient httpClient = new HttpClient(); httpClient.BaseAddress = new Uri(@"https://dummy.restapiexample.com/api/v1/employees"); string path = "ididcontent.json"; string response =

问题 I am trying to call an api during the blazor(client side) startup to load language translations into the ILocalizer. At the point I try and get the .Result from the get request blazor throws the error in the title. This can replicated by calling this method in the program.cs private static void CalApi() { try { HttpClient httpClient = new HttpClient(); httpClient.BaseAddress = new Uri(@"https://dummy.restapiexample.com/api/v1/employees"); string path = "ididcontent.json"; string response =

问题 I am trying to figure out how does asynchronous code work in Javascript. Now, I understand that there is actually one single thread in JS that executes jobs in a queue, and it can only start executing the next job if the current one is completed (i.e. if all of the sync code or an async function is completed). Now, the confusing part is what actually counts as an asynchronous function - what actually gets put into a separate job in the queue, and what doesn't. For start, we have the async

问题 I need the client side code to wait for the called server side (google.script.run) function to complete before running any more code. The withSuccessHandler(successFunc) does not cause lines of code that are after the server call to wait. What I've done: async function func(){ await google.script.run.withSuccessHandler(myFunc).serverFunc(); console.log("done"); } func(); How can the code wait to execute the console.log line until after the server side function resolves? 回答1: How about this

问题 I need the client side code to wait for the called server side (google.script.run) function to complete before running any more code. The withSuccessHandler(successFunc) does not cause lines of code that are after the server call to wait. What I've done: async function func(){ await google.script.run.withSuccessHandler(myFunc).serverFunc(); console.log("done"); } func(); How can the code wait to execute the console.log line until after the server side function resolves? 回答1: How about this

问题 The below code works perfectly: const Course = mongoose.model('Course',courseSchema) async function foo(){ const nodeCourse = new Course({ name: "Node JS Course", author: "foo", tags: ['node','backend'] }) const result = await nodeCourse.save() console.log(result) } foo() But this one gives an error: const Course = mongoose.model('Course',courseSchema) (async ()=>{ const nodeCourse = new Course({ name: "Node JS Course", author: "foo", tags: ['node','backend'] }) const result = await