Queue print requests

promiseLoop.js

function promiseLoop() {
	var printData = [
        { "type": "pdf", "data": "assets/1.pdf" },
        { "type": "pdf", "data": "assets/2.pdf" },
        { "type": "pdf", "data": "assets/3.pdf" },
        { "type": "pdf", "data": "assets/4.pdf" },
        { "type": "pdf", "data": "assets/5.pdf" }
    ];
    var printers = [
        { "printer": "PDFCreator" },
        { "printer": "PDFCreator" },
        { "printer": "PDFCreator" },
        { "printer": "PDFCreator" },
        { "printer": "PDFCreator" }
    ];
    var chain = [];

    for(var i = 0; i < printData.length; i++) {
        (function(i_) {
            //setup this chain link
            var link = function() {
                return qz.printers.find(printers[i_].printer).then(function(found) {
                    console.log("Printing" + printData.data);
                    return qz.print(qz.configs.create(found), [printData[i_]]);
                });
            };

            chain.push(link);
        })(i);
        //closure ensures this promise's concept of `i` doesn't change
    }
        var lastLink = null;
        chain.reduce(function(sequence, link) {
            lastLink = sequence.then(link);
            return lastLink;
        }, qz.websocket.connect());

        //this will be the very last link in the chain
        lastLink.catch(function(err) {
            console.log(err);
        });
}