Installing NodePie on Ubuntu

I was transferring my latest creation over to my hosted Ubuntu server and came across the most annoying error. I had to reinstall the NodePie module because it relies on compiled C code. I kept getting an error though about something called lib-expat.
Anyhow, turns out you need to apt-get a new library:
sudo apt-get install libexpat1-dev

GitHub to the rescue:https://github.com/astro/node-xmpp/issues/33

JSDOM Memory leaks

JSDOM is a great little module for NodeJS which lets you parse a DOM on the server. The only problem is that it has a memory leak. Not a big deal if you are only going to instantiate a couple times. A little trickier if you are screen scraping and need to call it 1000s of times. I luckily found a work around. Instead of creating a new window every time you want to parse some code, simply keep the same window around and switch what it is displaying:

From the google groups:

I’m basically doing this:

var jsdom = require(‘jsdom’);
var document = jsdom.jsdom(‘<html><body>’);
var window = document.createWindow();

var JQUERY_URL = ‘http://localhost/js/jquery-1.4.4.min.js’;

function foo(text) {
document.innerHTML = ‘<html><body>’ + text;
jsdom.jQueryify(window, JQUERY_URL, function() {
var $ = window.$;
console.log(document.innerHTML);
});

}

setInterval(function() {
foo(“Text”);

}, 1000);

And the process’ memory increases and eventually terminates. How do
you suggest I should reuse the DOM?

I am trying this for now:

function foo(text) {
document.innerHTML = ‘<html><body>’ + text;
if (!window.$) {
jsdom.jQueryify(window, JQUERY_URL, function() {
var $ = window.$;
console.log(document.innerHTML);
});
} else {
var $ = window.$;
console.log(document.innerHTML);
}

}

Dynamic DIV IDs in Jade

Jade is an HTML templating language that works with Node.js and a bunch of other languages. It takes structured templates and converts them into HTML. Jade uses indentation to show what code should be within an HTML tag.

It is also possible to use variables to generate text, they call it Interpolation and it is a very handy feature. However, it is sometimes a little tricky to figure out how to use variables for attributes in tags.

For example if you want the variable local to serve a link in an Anchor tag, this would work:

a(href=local) Test Link

You can also combine variables and text:

a(href=’http://localhost:3000/page/’ + next_page ) Next

Doing the same for DIV IDs was a little trickier though. Since there is short had for assigning IDs, I thought I could just paste the variable in the shorthand. That didn’t work. However, using an approach similar to the Anchor tag does. Try this for using variables to assign the ID for a DIV:

div(id=permit_id)