Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.javascript > #40082

Re: Pause for series of fetch calls

Show all headers | View raw

fredag 21 maj 2021 kl. 01:52:23 UTC+2 skrev Andrew Poulos:
> On 21/05/2021 9:06 am, Andrew Poulos wrote: 
> > On 20/05/2021 10:08 pm, Jon Ribbens wrote: 
> >> On 2021-05-20, Andrew Poulos <ap_...@hotmail.com> wrote: 
> >>> I need to: 
> >>> 
> >>> - make a series of fetch calls 
> >>> - when they all have resolved do some other normal (non-fetch) calls 
> >>> - make a another series of fetch calls 
> >>> - when they all have resolved continue 
> >>> 
> >>> I've only used async/await in a very basic way and I've been unable to 
> >>> work out how make everything wait for the fetch calls to resolve before 
> >>> making other calls. 
> >> 
> >> Do you really mean a *series* of fetch calls? i.e. that each one can 
> >> only begin once the previous one has completed? Or do you mean you 
> >> have a set of fetch calls that you want to run in parallel? 
> >> 
> >> If it's the former then: 
> >> 
> >> const urls = [ "https://example.com/", "https://example.org/" ... ] 
> >> const results = [] 
> >> for (const url of urls) results.push(await fetch(url)) 
> >> 
> >> If it's the latter then it depends on what you want to happen if any 
> >> of the fetches fail. If you want to give up as soon as any of them 
> >> fail, do: 
> >> 
> >> const results = await Promise.all(urls.map(url => fetch(url))) 
> >> 
> >> If you want to always wait for them all to complete, then you could do: 
> >> 
> >> const results = await Promise.all( 
> >> urls.map(url => fetch(url).catch(err => err))) 
> >> 
> >> and then results will each be a fetch result or an error. 
> > 
> > Sorry but I just don't get it :-( 
> > 
> > I tried this 
> > 
> > const urls = ['upload/test.php','...]; 
> > 
> > const results = async () => { 
> > await Promise.all( 
> > urls.map(url => fetch(url) 
> > .then(response => response.json()) 
> > .then(data => { 
> > console.log('Success: ', data); 
> > }) 
> > .catch(err => err))); 
> > }; 
> > 
> > results(); 
> > 
> > console.log('done');
> Doh, it works if I write it correctly
> const results = async () => { 
> await Promise.all( 
> urls.map(url => fetch(url) 
> .then(response => response.json()) 
> .then(data => { 
> console.log('Success: ', data); 
> }) 
> .catch(err => err)));
> console.log('done'); 
> }; 
> 
> results(); 
> 
> Andrew Poulos
Yeah it may work but the syntax is mental to do two things in serial..... Just saying....

Back to comp.lang.javascript | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Pause for series of fetch calls Andrew Poulos <ap_prog@hotmail.com> - 2021-05-20 19:02 +1000
  Re: Pause for series of fetch calls Julio Di Egidio <julio@diegidio.name> - 2021-05-20 02:24 -0700
    Re: Pause for series of fetch calls Julio Di Egidio <julio@diegidio.name> - 2021-05-20 02:41 -0700
  Re: Pause for series of fetch calls Jon Ribbens <jon+usenet@unequivocal.eu> - 2021-05-20 12:08 +0000
    Re: Pause for series of fetch calls Julio Di Egidio <julio@diegidio.name> - 2021-05-20 05:34 -0700
    Re: Pause for series of fetch calls Andrew Poulos <ap_prog@hotmail.com> - 2021-05-21 09:06 +1000
      Re: Pause for series of fetch calls Andrew Poulos <ap_prog@hotmail.com> - 2021-05-21 09:52 +1000
        Re: Pause for series of fetch calls Jonas Thörnvall <jonas.thornvall@gmail.com> - 2021-05-20 23:34 -0700

csiph-web