Support put job with loop about fivebeans

[ceejbot]

You're creating three clients there, once per trip through the loop, which is probably not what you want. If you're looping through data that you want to do something asynchronous with, use a continuer function. I updated the emitjobs.js example to show this off, but here's a stripped down example:

var fivebeans = require('fivebeans');
var joblist = [ 'one', 'two', 'three', 'four', 'five' ];

var doneEmittingJobs = function()
{
    console.log('We reached our completion callback. Now closing down.');
    emitter.end();
    process.exit(0);
};

var continuer = function(err, jobid)
{
    console.log('emitted job id: ' + jobid);
    if (joblist.length === 0)
        return doneEmittingJobs();

    emitter.put(0, 0, 60, JSON.stringify(['testtube', joblist.shift()]), continuer);
};

var emitter = new fivebeans.client('localhost', 11300);
emitter.connect(function(err)
{
    emitter.use('testtube', function(err, tname)
    {
        console.log("using " + tname);
        emitter.put(0, 0, 60, JSON.stringify(['testtube', joblist.shift()]), continuer);
    });
});

First you define a continuer function that knows how to tell when you've looped through all your data and knows how to kick off processing on the next chunk of data. Then you invoke your processing on the first data item & pass the continuer as a callback. This is a general pattern you'll use often when looping through data in node. There's a pretty good explanation of this pattern in this article, with a more for-loop-y variation on it.

Or you could use a flow control module to help with loops. I often use async for this.

[jspaper]

@ceejbot Thank you provide those information:)