Add Support for channels

[mmoelli]

As a Merchant I want to use channels as additional dimension so that I'm able to save more than one stock per SKU.

[emmenko]

Match by channel by key instead of id

We want to provide the possibility to only pass the key of a channel. The tooling then has the find the corresponding sphere-id to do the actually POST call.

Refs commercetools/sphere-node-cli#17

[nkuehn]

+1 for channels and all the other attributes of the inventory. It's all just flat data.
Channel by key is a must, nicola is right in that.

[nkuehn]

@PhilippSpo see here concerning the current request from the partner project.

[ajdinstel]

Hi, working on a commercetools integration for a US client who will need to manage inventory levels at the channel level. This will be in support of a 'pick up in store' feature which will need to reflect accurate inventory of a given sku in a specific location (channel). Have there been any developments on this? If this isn't supported we're probably going to end up pushing the client towards a third-party like locally.com.

[stmeissner]

@hisabimbola Issue popped up again in a request from a partner.

[butenkor]

@emmenko actually best would be if API would allow to use key instead of ID for channel references.

@ajdinstel i am not sure if i understood you correctly but API already supports channels for inventories: http://dev.commercetools.com/http-api-projects-inventory.html#inventoryentrydraft
and you can use node SDK(https://github.com/sphereio/sphere-node-sdk) to mange channels and inventories directly. Also if i am not mistaken by the middle of November it is planned that API would support geospatial search on channels endpoint (http://support.sphere.io/forums/201737-api/suggestions/13368702-add-geolocation-to-channel-and-be-able-to-query-by). Matched channels can be combined with OR or AND operator and used to filter products accordingly.