filter by channel works with arrays only

[househippo]

Original: https://forums.couchbase.com/t/sg-filter-by-channel-works-with-arrays-only/8140

Found something interesting that some people might get tripped up on.

I used the default sync function:

function(doc){
channels(doc.channels)
}
I added the below document into SG with "channels":"bob"

{
"_id":"12345",
"channels":"bob"
}

And when I tried to filter by channel via

http://hostname:4984/{db}/_changes?filter=sync_gateway/bychannel&channels=bob
it returned an empty array

When I tried http://hostname:4984/{db}/_changes?filter=sync_gateway/bychannel&channels=*
with a "*" , it worked but I got all the documents in the DB.

But when I changed it to "channels":["bob"] an array everything worked fine 👍 and filters by only docs in the "bob" channel.
{
"_id":"12345",
"channels":["bob"]
}

It accepts one or more arguments, each of which must be a channel name string, or an array of strings.
In the docs when it talks about channels( ) its not that clear about arrays and filter by array only or is that a bug?

Source: http://developer.couchbase.com/documentation/mobile/1.2/develop/guides/sync-gateway/sync-function-api-guide/routing/index.html

[ajres]

I just tested this against master and filtering by a single channel (not in an array) is working on both the ADMIN API and PUBLIC API.

@househippo how are you sending the request, if you are using a cli tool like curl can you post the full command with quoting and escaping.

[ajres]

@adamcfraser suggested that the issue is not the filter channels but the doc "channels" property. I have tested and confirmed that the document "channels" property must be an array, a single string value will not map the document to a channel.

[ajres]

This issue is only occurs when no explicit sync function has been defined the SG config.json. In this case a Javascript interpreter is not used and the doc.channels property is extracted from the document body directly in golang.

If the default sync function is explicitly defined in the config.json file then the Javascript interpreter is invoked and the single channel string value is correctly parsed.