Simple substring filter

swigFilter.js

/*
checkout this 
http://paularmstrong.github.io/swig/docs/#filters-custom

setup like below
// set template engine
var swig = require('swig');
var swigFilter = require('./swigFilter');
var swigTag = require('./swigTag');

app.engine('html', swig.renderFile);
swig.setFilter('substring', swigFilter.substring);
swig.setFilter('printDate', swigFilter.printDate);
swig.setTag('iterate', swigTag.iterate.parse, swigTag.iterate.compile, swigTag.iterate.ends);
swig.setDefaults({
    cache: false   // default 'memory'
});

use : 
{{ someString|substring(10) }}
*/
exports.substring = function (input, count) {
    return input.toString().substr(0, count);
};

/*
use :
{{ myDate|printDate('d') }}
*/
exports.printDate = function (input, type) {
    var str, year, month, day;

    if (input.length == 8 && type != 'd') {
        year = input.slice(0, 4);
        month = input.slice(4, 6);
        day = input.slice(6, 8);

        if (month.length == 2 && month.slice(0,1) == '0') month = month.slice(1, 2);
        if (day.length == 2 && day.slice(0,1) == '0') day = day.slice(1, 2);

        str = month + '월 ' + day + '일';

    } else if (type == 'D') {

        day = input.slice(input.length - 2, input.length);
        if (day.length == 2 && day.slice(0,1) == '0') day = day.slice(1, 2);

        str = day + '일';

    } else {
        day = input.slice(input.length - 2, input.length);
        if (day.length == 2 && day.slice(0,1) == '0') day = day.slice(1, 2);

        str = day;
    }

    return str;
};