Stream model

stream.js

// returns a rendered list of items

res.get(req, res, next) {

    /**
     *  A stream object accepts an array of content id UUIDs or CAPI search strings
     *  and returns a blob of HTML representing the stream.
     *
     *  The returned HTML is a sequence of article card components.
     */

    var content = Promise.all(
        ft.get(['d3fe0b06-9e43-11e3-b429-00144feab7de', ...], 
        fastft.get('regions:london'), 
        market.get('lse:twt')
        ...
      ).then(function (items) {

        new Stream({
                api: [..., ...],
                fastft: [..., ...],
                market: [..., ...],
                userprefs: [..., ...]
            })
            .sortByDate                             // Orders the items by date descending
            .sortByVisualTone                       // Groups the items by their tone, Eg. news, analysis, comment etc.
            .applyTextures                          // Annotate the items with texture, Eg. highlight some items
            .withFastFT(true)                       // Interleave the fastFT data
            .showRelatedTopics(5)                   // Show n related topics at the foot of the stream
            .requestingUser({ id: req.params.uid }) // Metadata about the person who requested the stream
            .isFollowable(true)                     // Can someone follow this stream?
            .isUserStream(true)                     // Not sure we need this distinction?
            .title('Save for later')                // Display title
            .id('forlaters')                        // DOM id (?)
            .page(1)                                // Pagination, Eg. '1 of n'
            .applyFilters()                         // API v1 filter configation. Eg, { regions: ['London', 'New York'] }
            .notFound(message)                      // Message to display upon the stream being empty, Eg. 'Sorry. No articles found'
            .render                                 // Respond with a blob of HTML representing the stream.
        })
}

Arjun and I spoke about this quite a bit.

• We think the controllers should still be in charge of fetching the data and passing it to the stream.
• The Stream model is really a view model the returns an object.
• The stream model can be passed to the res.render to be converted to HTML

The main objectives are to a) centralise the messy splay of streams logic and to begin to unit test it, b) keep all this logic out of any individual controller.