Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Who is building clouds for the independent developer? Exploding turkeys and how not to thaw your frozen bird: Top turkey questions Featured on Meta. Now live: A fully responsive profile. Reducing the weight of our footer. Linked Related Hot Network Questions. Question feed.
Stack Overflow works best with JavaScript enabled. Accept all cookies Customize settings. Show 14 more comments. Don't forget to handle errors! The following code is based on Augusto Roman's answer. But we don't check the result if cb cb err.
Vince Yuan Vince Yuan VinceYuan the callback is confusing me. What would I place as the cb argument? Abdul Sounds like you are very new to node.
Take a look at this tutorial: tutorialspoint. Abdul maybe it would be good if you share with the rest of the class what you have figured out? Is there a way to see the speed of the download? Show 7 more comments. Kelvin Omereshone 2 2 silver badges 11 11 bronze badges. Abdul You specify the callback with a function only if you need to do something when the file has been successfully fetched. It would be good to check the status code before saving: response.
But we don't check the result return cb err. Buzut Buzut 4, 4 4 gold badges 41 41 silver badges 50 50 bronze badges. The request module just works straight for HTTPs. S Ventura. It's more error prone without a doubt. Anyway, in any case where using request module is an option, I'd advise it as it's way higher level and thus, easier and efficient. Alex, nope, this is an error message and there's a return. So if response. Thank you for showing example using request module.
Show 3 more comments. MikeL 5, 38 38 silver badges 41 41 bronze badges. Augusto Roman Augusto Roman 6 6 silver badges 4 4 bronze badges. What for are you storing request into a variable? You are right, there is no need to save the request, its not used anyway. That's what you mean? Yes, I think that's what polkovnikov. Per default the fs. Bjarke Pjedsted Bjarke Pjedsted 4 4 silver badges 8 8 bronze badges. Two comments on this: 1 it should probably reject Error objects, not strings, 2 fs.
This works great! No errors popped up but the. Removing the logic for the flag fixed it. Just wanted to point that out if someone had the issues with the approach.
Is there a memory leak in this answer: stackoverflow. You can add timeout like I did in http. The memory leak is only if the file take too long to be downloaded. Based on the other answers above and some subtle issues, here is my attempt. Check the file does not exist before hitting the network by using fs.
Only create the fs. This reduces the amount of fs. Even on a OK we can still possibly reject due to an EEXIST file already exists imagine another process created the file whilst we were doing network calls. Recursively call download if you get a Moved Permanently or Found Moved Temporarily redirect following the link location provided in the header.
The issue with some of the other answers recursively calling download was that they called resolve download instead of download This way the nested chain of promises resolve in the correct order. It might seem cool to clean up the temp file asynchronously, but I chose to reject only after that completed too so I know that everything start to finish is done when this promise resolves or rejects.
Josh Peak Josh Peak 4, 4 4 gold badges 33 33 silver badges 48 48 bronze badges. You shouldn't waste resources doing the download if the destination file already exists.
Do the check first if possible. Phil Really good point. I have updated the example with an earlier guard check before falling into the recursive networking calls but left the success file handling code the same. I started this blog as a place to share everything I have learned in the last decade. I write about modern JavaScript, Node. The newsletter is sent every week and includes early access to clear, concise, and easy-to-follow tutorials, and other stuff I think you'd enjoy!
No spam ever, unsubscribe at any time. How to download a file in Node.
0コメント