gistfile1.txt

// example breadboard script
//
// the logic behind http://thinkdifferent.ly/stuff/breadboard7.mp4
//
// this same script is generated if you wire your circuit in the UI, but
//  i thought it would be interesting to share how to create circuits from
//  the underlying script (the UI issues these same commands).

// there are a few basic concepts: devices, wires, and channels.  devices
//  are data stream sources, functions, and sinks.  every device has zero
//  or more "ports" which are ingress and egress points for streaming data.
//  wires connect data from output ports to input ports.  channels allow
//  communication with external connections (e.g., websocket connections for
//  the UI, etc.).  so let's take a look at how to create the circuit you 
//  saw in the video by script:

// first we need to create a circuit and set it as our working context.

create circuit test;
use test;

//
// let's create a channel so we can spy on tweets as they come in
// 
create channel tweets;

//
// tweeter is a device that connects to twitter's filterstream streaming tweets
//

create device tweeter-1 as tweeter {"filters":["ukraine", "russia", "putin", "news", "crimea"]};

// now let's connect the tweeter output to the channel input via a
//  "channeler" device; this device takes any messages it receives and
//  publishes them to a channel (allowing you to see them in a console, etc.)

create device tweet-channel as channeler {"channel":"tweets"};
create wire tweet-wire from tweeter-1.tweets to tweet-channel.data;

// json-path devices effectively operate as xpath would on streaming xml.
// in this case, let's pull out the screen names from each tweet and send it
//  to a special type of lru device.  by default this lru has a 1 minute window
//  and computes a histogram.  in the device UI, if it's a link, it will render
//  it as a clickable link that opens in a new window.

create device tw-users as json-path {"path":"$.tweet.screen_name_s"};
create device tw-users-lru as lru {"field":"value"};

create wire w-0 from tweeter-1.tweets to tw-users.data;
create wire w-tw-users from tw-users.value to tw-users-lru.data;

// let's use another json-path instance to pull out the first media_url_ss field
//  value which is always an image url.  we'll send those to another instance of
//  the lru, this time with a "media" flag telling it to expect images (and display
//  them instead of clickable links)

create device tw-media as json-path {"path":"$.media[0].media_url_ss"};
create device tw-media-lru as lru {"field":"value", "media":true};

create wire w-1 from tweeter-1.tweets to tw-media.data;
create wire w-tw-ctry from tw-media.value to tw-media-lru.data;

// now we'll use a json-path instance again and pull the hashtags_s_mv array
//  of hashtags from each tweet.  because most devices expect one type of value
//  to operate on, we'll connect the output of the json-path instance to an
//  instance of a device called "expander".  it takes any array of values and
//  expands them into individual messages, one for each element of the array,
//  so they can be operated on individually downstream; in this case, one
//  hashtag at a time.  then on to another lru.

create device tw-tags as json-path {"path":"$.tweet.hashtags_s_mv"};
create device expander-2 as array-expander;
create device tw-tags-lru as lru {"field":"value"};

create wire w-2 from tweeter-1.tweets to tw-tags.data;
create wire w-tw-tags from tw-tags.value to expander-2.in;
create wire w-tw-tags-1 from expander-2.out to tw-tags-lru.data;

// this is the same as the above, except we pull a list of urls out,
//  and since they're object, we run them through another json-path
//  instance to pull the actual url out of it, then on to another lru
//  device.

create device tw-urls as json-path {"path":"$.urls"};
create device expander-1 as array-expander;
create device tw-urls-1 as json-path {"path":"$.value.expanded_url_tt"};
create device tw-urls-lru as lru {"field":"value"};

create wire w-3 from tweeter-1.tweets to tw-urls.data;
create wire w-tw-urls-1 from tw-urls.value to expander-1.in;
create wire w-tw-urls-2 from expander-1.out to tw-urls-1.data;
create wire w-tw-urls-3 from tw-urls-1.value to tw-urls-lru.data;

// and that's it!  thanks for reading.  @jrecursive