NW.js - PouchDB - Unable to use PouchDB via require() in node webkit

Question

I am new to pouchdb and nw.js and may be this question is a little bit too simple, (sorry for my ignorance).

I am trying to to use pouchdb in a nw.js project via require() but with no luck.

According to the documentation for the pouchdb setup , under Node.js section, I dit it exactly as it says with no success.

After that I installed leveldown component into the project, and I have followed the following instructions under https://github.com/nolanlawson/pouchdb-nw github project.

So, at this point, I have already done the following:

nw-gyp configure --target=0.12.3 / in the node_modules/leveldown directory

nw-gyp build

Then, according to pouchdb.com/guides/databases.html I have:

var PouchDB = require('pouchdb');
var db = new PouchDB('kittens');

but again with no luck. In addition, by running the following:

db.info().then(function (info) {console.log(info); });

getting no response.

Note: If just include this <script src="../node_modules/pouchdb/dist/pouchdb.min.js"></script> in the index.html file, everything works like a charm.

nw.js version: 0.12.3 / pouchdb version: 5.2.1

What am I missing?

Answer 1

Finally I found a working solution to my problem.

The work-around is as follows:

1) I updated pouchDB to 5.3.0

npm update pouchdb --save

2) Then navigate to node_modules/leveldown

cd node_modules/leveldown

3) configure gyp with nw.js target version

sudo nw-gyp configure --target=0.12.3

4) Build again the nw gyp

nw-gyp build

5) And then in my javascript module file

 var PouchDB = require('pouchdb');
    var arincPouchDB = new PouchDB('./db/arincAirports'); // new pouch db for node without adapter // means you get leveldb adapter in this case.
    var jsonData = require("../datasrc/output/data.json");
    arincPouchDB.bulkDocs(jsonData);

    arincPouchDB.info().then(function (info) {
        console.log(info);
    });

6) And the console says...

Objectadapter: "leveldb" 
auto_compaction: false
backend_adapter:"LevelDOWN"
db_name: "./db/arincAirports"doc_count: 12
update_seq: 12
__proto__: Object...

Note: If you try to use pouchDB from a script tag in your html file, and at the same time you have to use it in a javascript function, that will be exported via module exports e.g

exports.pouchDBFunction = new pouchDBFunction();

and to use this exported function in another javascript file, like this

var json2PouchDB = require("./js/pouchDBFunction.js");
 json2PouchDB.pouchDBFunction;

will not work and you will get the error pouchdb is not defined. That's why you need to have pouchDB via require() function.

Hope this workaround helps...

Answer 2

Did you try the demo? https://github.com/nolanlawson/pouchdb-nw-hello-world There are quite a few steps to install PouchDB correctly in NW.JS.

Edit: oh wait, yes, you did see the demo already. Maybe the issue is that LevelDOWN is incompatible with your version of NW? In my demo I was using an older version of NW than you.

Yet another option is to use the websql adapter inside of Node, which should give you similar performance to LevelDB while possibly being easier to compile than LevelDOWN. If all else fails, I'd recommend filing an issue on the LevelDOWN repo; they have tons of issues related to building for X version of Node on Y architecture on Z operating system, so your combination of XYZ might be a unique one.