Send parameters from jade to js/node

Question

I am trying to pass variables from leaflet/jade to a js/node file. I am using node + express + leaflet + js I am doing it the following way but I am not getting the values. Here is the code I am using:

app.js

var express = require('express');
var routes = require('./routes');
var tiles = require('./routes/tiles');
var http = require('http');
var path = require('path');
var app = express();
app.set('port', process.env.PORT || 3000);
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
app.use(express.favicon());
app.use(express.logger('dev'));
app.use(express.json());
app.use(express.urlencoded());
app.use(app.router);
app.use(express.static(path.join(__dirname, 'public')));

if ('development' == app.get('env')) {
  app.use(express.errorHandler());
}

app.get('/', routes.index);
app.get('/tiles', tiles.tiles);

http.createServer(app).listen(app.get('port'), function(){
  console.log('Express server listening on port ' + app.get('port'));
});

index.js //the index file that renders the index.jade file

exports.index = function(req, res){
  res.render('index');
};

index.jade //the jade file, the line where I am sending the params is "tiles?z={z}&x={x}&y={y}"

doctype html
html
  head
    title Tile Server Example
    meta(charset='utf-8')
    meta(name='viewport', content='width=device-width, initial-scale=1.0')
    link(rel='stylesheet', href='http://cdn.leafletjs.com/leaflet-0.7.1/leaflet.css')
  body
     #map(style='width: 800px; height: 800px')
     a(href='tiles') < tiles >
    script(src='http://cdn.leafletjs.com/leaflet-0.7.1/leaflet.js')
  script.
    var map;
    var mbTiles = new L.tileLayer('tiles?z={z}&x={x}&y={y}', {
    tms: true,
    attribution: 'this is a test',
    opacity: 0.7
    });
    map = new L.Map("map",{
    zoom: 18,
    center: [12.83563,77.68312],
    layers: [mbTiles]
    }); 

tiles.js //here is where I get the params, I am displaying them via console

 var x = "", y = "", z = "";

module.exports = function(req, res){    
    x = req.query.x; 
    y = req.query.y;
    z = req.query.z;    

    console.log("z="+z+"&x="+x+"&y="+y);

    var sqlite3 = require('sqlite3').verbose();
    var db = new sqlite3.Database('routes/tiles.mbtiles');
    var sql = "SELECT * FROM tiles WHERE zoom_level = "+z+" AND tile_column = "+x+" AND tile_row = "+y;

    db.each(sql, function(err, row) {
            console.log(sql);
            res.writeHead(200, {'content-type':'image/jpg'});
            res.write(row.tile_data);
            res.end();
    }); 
    db.close();
};

Any idea?

Answer 1

Try to change, the way you export your modules. In tiles.js :

Change:

exports.tiles = function(req, res){ ...

To:

module.exports = function(req, res){ 

And in app.js :

app.get('/tiles', tiles.tiles)

To

app.get('/tiles', tiles)

UPDATE

Also, add res.end() after setting headers and needed information to change response into a finished state.

res.writeHead(200, {'content-type':'image/png'});
res.write(row.tile_data);
res.end();