Spike node.couchapp.js

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Thanks to node.couch.js, I think I have finally exhausted the subject of the CouchDB changes API. Interesting stuff, especially coupled with node.js. At this point, I think I am just about ready to get started with actual work on my chain's purpose (a mechanism for maintaining recipes from last year's chain). But before I do...

I think I will spike on node.couchapp.js. Node.couchapp.js is aiming to be a couchapp implementation in node.js. I have no idea how complete an implementation it is, but it has one major advantage in my eyes over couchapp: it's written in javascript/node.js vs. python.

I clone the repository:

cstrom@whitefall:~/repos$ git clone git://github.com/mikeal/node.couchapp.js.git
Initialized empty Git repository in /home/cstrom/repos/node.couchapp.js/.git/
remote: Counting objects: 70, done.
remote: Compressing objects: 100% (68/68), done.
remote: Total 70 (delta 22), reused 0 (delta 0)
Receiving objects: 100% (70/70), 14.81 KiB, done.
Resolving deltas: 100% (22/22), done.

It takes me a little bit of rooting about, but I finally determine that the script that needs to be executed is lib/bin.js:

cstrom@whitefall:~/tmp/test_node_couchapp_js$ node ~/repos/node.couchapp.js/lib/bin.js -h
Invalid Option: -h
cstrom@whitefall:~/tmp/test_node_couchapp_js$ node ~/repos/node.couchapp.js/lib/bin.js help
-d,  --design :: File or directory for design document(s)
-t,  --test :: Run tests.
-s,  --sync :: Sync with CouchDB.
-c,  --couch :: Url to couchdb.

The entire package appears to be installable via something called NPM (Node.js package Manager). I opt to avoid this (for now) as it seems to be very much a work in progress. Besides I am able to get the help output described in the node.couchapp.js README without NPM installation.

At this point, I am very much flying blind. I do not know which, if any of those options are required. I am not sure what the format of the design documents should be. I am not entirely clear what --sync should do, though I'd guess that it is analogous to couchapp's "push".

Well, what happens when I run the command without any options:

cstrom@whitefall:~/tmp/test_node_couchapp_js$ node ~/repos/node.couchapp.js/lib/bin.js
cstrom@whitefall:~/tmp/test_node_couchapp_js$

Hmm... It would seem nothing. A quick scan of the CouchDB log confirms this.

What happens when I supply a CouchDB url?:

cstrom@whitefall:~/tmp/test_node_couchapp_js$ node ~/repos/node.couchapp.js/lib/bin.js -c http://localhost:5984/seed
cstrom@whitefall:~/tmp/test_node_couchapp_js$

Nothing again.

Well what happens when I supply an empty design document directory along with a CouchDB URL?

cstrom@whitefall:~/tmp/test_node_couchapp_js$ node ~/repos/node.couchapp.js/lib/bin.js -d . -c http://localhost:5984/seed
Error: Cannot find module '/home/cstrom/tmp/test_node_couchapp_js'
    at loadModule (node.js:574:15)
    at require (node.js:700:12)
    at Object.<anonymous> (/home/cstrom/repos/node.couchapp.js/lib/bin.js:22:16)
    at Module._compile (node.js:721:23)
    at node.js:749:20
    at fs:51:23
    at node.js:810:9

Hrm... Well how about an empty dot-JS file?

cstrom@whitefall:~/tmp/test_node_couchapp_js$ node ~/repos/node.couchapp.js/lib/bin.js -d foo.js -c http://localhost:5984/seed
cstrom@whitefall:~/tmp/test_node_couchapp_js$

Back to nothing.

Perhaps I need to tell it to sync?

cstrom@whitefall:~/tmp/test_node_couchapp_js$ node ~/repos/node.couchapp.js/lib/bin.js -d foo.js -c http://localhost:5984/seed -s
No design docs in provided modules!

Ah, now we're getting somewhere.

After a little fiddling around, I create a "design document" that looks like this:

{
  show: "function() { return 'foo'; }"
}

Even with that, I still get:

cstrom@whitefall:~/tmp/test_node_couchapp_js$ cat foo.js 
{
  show: "function() { return 'foo'; }"
}
cstrom@whitefall:~/tmp/test_node_couchapp_js$ node ~/repos/node.couchapp.js/lib/bin.js -s -d foo -c http://localhost:5984/seed
No design docs in provided modules!

I have to call it a night at this point. Hopefully I will be able to make more progress on this tomorrow.


Day #70