is there a way to put individual results of map (vs the entire seq) into the channel returned by go?

@swizzard: I thought the channel returned by go only had one result?

swizzard: no, the usual way to do this is to create a dedicated out channel and have the go block put its values into that, and ignore the value actually put on go’s return value channel.

is there a pattern for using core.async which is analogous to Q.all() in javascript?

Example: I have an Outfit (collection of maps representing clothing items). Each item must be updated asynchronously, and only once all updates are complete, do something with the "updated" Outfit

Do you have separate go blocks for each item?

If so, you can just async/merge their resulting channels into a single channel. If you need to block until all of the merged channels’ values have been delivered on the merged channel, you can use async/into. Of course, you can do a lot of this manually using go-loops and alts!, too.

@jeremyraines: http://clojurescriptmadeeasy.com/blog/promises-with-core-async.html

thanks, I'll check those out

@erik_price: I am trying to do it that way, not sure what I'm doing wrong

https://gist.github.com/jraines/4d2bc117e83fa5b0f9af

the original-image-dimensions fn is just doing this: http://stackoverflow.com/questions/623172/how-to-get-image-size-height-width-using-javascript/626505#626505

once I have the height and width of the image, i'm trying to put it to one channel per item

It looks like you create a new Image object, but then it just gets garbage collected. Unless I’m misunderstanding something?

yeah, it's created solely for grabbing the height and width

I see. I’m not a DOM guru, didn’t know that was possible. You’re sure it isn’t being GC’d? Does your onload callback get executed?

yeah. Before I added the a/into it was printing out the first value of the result of a/merge

now nothing

I think you want a/map

no, scratch that

I was misreading your code

I dunno Jeremy, it looks right to me

ok, thanks for looking. If I can come up with a good next question, i'll follow up

That implies that not all of the merged channels are being closed (because until they are, the channel returned from merge doesn’t close, and until that closes, into doesn’t return a channel.

Ok good luck. I’ll be offline for a bit but back later tonight.

that makes sense

does the merge channel itself need to close? is so how would I know when to do it?

it does, but it closes automatically when all of the channels passed to merge are closed.

ok, thanks

g/l

that was it; needed to close the channel onerror since there was a broken image link in my data