It accepts a function and a delay time in milliseconds. The setTimeout() function schedules code for the runtime to execute once a set amount of time has passed. Use the await () Keyword to Pause Execution of Codes in Node. To use request with promises, install it like this: npm install requestĪnd then require("request-promise-native") in your code, like in the example above.Using setTimeout() to Wait for a Specific Time
When a timer's function is called varies depending on which method was used to create the timer and what other work the Node.js event loop is doing. Return new Promise(resolve => setTimeout(resolve, millis)) Ĭonst urls = await fetchUrls(INITIAL_URL) A timer in Node.js is an internal construct that calls a given function after a certain period of time. var sleep require ('sleep') sleep.sleep (5)//sleep for 5 seconds Is there a way that node.js can spawn a new thread for each request so that the second request does not have to wait for the first request to complete, or can I call sleep on specific thread only multithreading node. The sleep function is pretty straightforward: async function sleep(millis) millis - how long to sleep in milliseconds It just initiates another thread with a standing instruction to start after the given time. Our task gets executed after a certain time, but the thread itself never sleeps or waits. Similarly, PHP has sleep (2), and Python has time.sleep (2) to make the program stops for 2 seconds. Although this deserves the upvote, this is not a real 'sleep' functionality that we are used to. Upon each connection, the callback is fired, but if there is no work to be done, Node.js will sleep. In the following 'hello world' example, many connections can be handled concurrently. For example, in Java, you can use the Thread.sleep (2 1000) to halt the current thread execution for 2 seconds. About Node.js As an asynchronous event-driven JavaScript runtime, Node.js is designed to build scalable network applications. The setTimeout () method of the WindowOrWorkerGlobalScope mixin (and successor to tTimeout ()) sets a timer which executes a function or specified piece of code once the timer expires. Many programming languages provide a sleep () function that pauses the execution of the code for a certain amount of time. Much better, isn't it? Before I get into the details of how fetchPage() and fetchUrls() work, let's first answer your question of how to wait before fetching the next page. There’s no sleep () method in JavaScript, so you try to use the next best thing, setTimeout (). For instance, this would be your main function: const urls = await fetchUrls(INITIAL_URL) I am a big fan of the async library and I've used for a long time.
Delaying multiple page fetches with async/await
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