Heapsource Blog

Whenever I hear something good about D, it’s always related to the awesome compile-time capabilities built-in the language.

One powerful feature is the ability to read a text file from the file system and insert it into the source code; which can be done by using import.

The following is a straightforward example of declaring a property with the content of a file, it all happens at compile-time:

Gist showing Compile-time Imports

In the line #4 you can see how the mixin loadFile takes the file name and the property to be generated.

For security reasons, the compiler will look for files relative to all the paths specified either directly using the compiler flag -J or the directive stringImportPaths in any dub package.

Today we released express-winston v0.2.5, our express.js middleware for flatiron/winston.

Since its early versions, the library has experienced wide adoption and contributions from developers such as storify.com and has been featured in stackoverflow.com as the preferred choice for logging in express.js applications.

The library is also included in super frameworks like Greppy and tools like componentjs-tracing.

events.d - Event Object Model library for the D programming language

As other programming languages like C# provide it's own OOP Event model, this is library is an attempt to fix and inspire an Event Object Model for D programming language. Working with delegates and preserving closures, this library is perfectly suited for any project or library in D that requires more than one listener and one sender.

Example of Events.d

We're happy to announce http-parser.D, a set of bindings in [D Programming Language] (http://dlang.org) for the high performance library joyent/http-parser used in many projects including Node.js and Rust.

The bindings were initially included in Project Duv around a year ago, but we've now decided to split and maintain them in different repositories so other D projects are able to include the library without any effort.

http-parser.D is fully tested and is compliant with DMD compiler and LDC compilers.

Example:

Check the Gist for a simple example

Today's web applications are facing all kind of security intrusions commonly derived from Password cracking attacks. The user itself could even write the password somewhere accessible to untrusted parties making it easy for identity thieves access private information or worst, take over the user account.

One of the most effective ways to address this situation is requiring additional secrets that real account owners could obtain from other channels after they signed in with their regular email and password. These additional secrets are known as One-Time-Passwords and are the keystone of Two Factor Authentication.

Our contributions for the past week covers our Gems, Ruby on Rails and Elixir.

To save myself some typing I’ll be using the following conventions:

A command prefixed by sysadmin$ is meant to be run in your local workstation.

A command prefixed by user@vpshost:path# is meant to be run in the vps under the specified user on the specified path.

Get Password-less SSH

If you’re anything like me then the first thing you do with a new VPS is set your password-less ssh login. If you haven’t, here’s how you do it:

https://gist.github.com/lacides/da055ff9ec7e2511ab14

If you’re on OSX or some other *nix without ssh-copy-id, the following one liner will work:

https://gist.github.com/lacides/8e5d06bcacb596df2fdb

Get Git

To get gitolite you need to install git, on debian based systems (like ubuntu) the following command will do it:

https://gist.github.com/lacides/72b1c1d7916efc12fbfa

If you want to learn how to install git on other systems take a look at http://git-scm.com/book/en/Getting-Started-Installing-Git

Get Gitolite

From the documentation: “Gitolite uses a single real (i.e., unix) user to provide secure access to git repos (...). Typically this user is git (...)”. So the first thing to do is create that user.

https://gist.github.com/lacides/e3234abbc3674fbaa832

Then, as the git user, get the code from github with:

https://gist.github.com/lacides/79f27552fd55af6eb9a4

Gitolite has a single server side command called gitolite, which can be installed running the install command that comes with the source. Running the install command using the ln flag will symlink the gitolite command to $HOME/bin (it assumes it exists). So:

https://gist.github.com/lacides/813fdb9725bc1fb2859f

Setup Gitolite

Now that you have gitolite installed on your VPS, you’ll need to finish the setup by running (you guessed it!) the setup command.

The setup command takes a ssh key that must not have access to the server. That means you’ll need to go back to your local workstation and generate a new ssh key.

https://gist.github.com/lacides/528cc31927843d70ae2a

Don’t forget to change the file’s ownership to the git user with chown.

https://gist.github.com/lacides/efd2cc4cba1b05e41540

Now run the setup command:

https://gist.github.com/lacides/1f87b33bea424da7acfc

Clone the admin repo

Gitolite comes with two repos: an empty one called testing to which all users have access and the gitolite-admin repo. The gitolite-admin repo is how you manage your gitolite server and you can pretty much do anything you want by pushing changes to it. Right now the only workstation with access to the gitolite-admin repo is the one from where gitadmin.pub came from, so go there and:

https://gist.github.com/lacides/90f317f520374c1e2de6

You can add users by putting pub keys on the keydir folder (user name is assumed to be the .pub file name), and you can manage repos and permissions by manipulating the conf/gitolite.conf file.

multilang-hstore - Multilang is a small library for translating database values for Rails 4 and Postgresql hstore

Our contributions this week cover the upcoming Rails 4, our Node.js modules and Gems.

FireUIPagedScrollView is a UIScrollView ready to paginate all the View Controllers you want.. all of them! :)

It also integrates with UIPageControl and UISegmentedControl.

iPhone and iPad Samples included.

It's almost impossible to maintain an express.js application in a single app.js file, so that's we've created pseudo, a simple loader of actions and middlewares for express.js

Available on the Node Package Manager: npm install pseudo

We absolutely love IconFinder.com, that's why we've created an Android app to browse and share Icons right from your Android Device.

Give it a try:

It downloads in a second (under 500kb)

Ads Free

Email the icons in different sizes to your buddies and designer collegues!

It's Free!

We built it, it's absolutely awesome :)

Download it now on the Android Marketplace, it's Free!

If you have any suggestion please drop us an email!

Almost every recents conversation we are having with new customers starts with "We want to develop an application for Android 3.1" and the main reason why they want to target that specific version is because is the latest version.

Pros and Cons

Even when using the latest features of the OS in a creative way is a plus to be "Featured" in the Market place, it will also cause a negative impact in the number of downloads in the Marketplace. Due the long list of Android Device Vendors, the customizations they make for the OS and their different mechanisms to upgrade the OS, the latest version of Android is not deployed to all devices immediately after the release.

At this time, Android 3.1 is the latest version and is installed in only 0.3% of all Android Devices out there. So if Google claimed this year at Google I/O 2011 that there are approximately 100 million activated Devices worldwide, Android 3.1 an it's 0.3% is near 300,000 devices while Android 2.2 and it's 64.6% is around 64,600,000 devices ready to install your new awesome app:

Check this pie chart for June, 2011:

Android 3.1(0.3%) = 300,000

Android 2.2(64.6%) = 64,600,000 devices.

As you see if you target Android 2.2 you will definitely get a decent range of devices and users that are able to install your app. Of course, if you target Android 1.6 you will get near 98% Android Devices ready to install your app, but you have to take in consideration that you may miss some good features like C2DM that is only available starting Android 2.2, so our recommendation is to target Android 2.2 that automatically make it available for later versions like 2.3, 3.0 and 3.1.

Where the numbers are