chodounsky.net - Jakub Chodounsky

Pro Tip - Change Vim Color Theme

2013-05-24T00:00:00Z

Pro Tip is a new section of this blog. It contains useful tips for programming professionals and computer power users. I think all of you, dear readers, are in this category. It should help you to be more productive and effective in daily tasks. Let’s start with the first one.

I like to use a notebook on different places and on various times. I like to code on a sunny day on my balcony. I like to lie on the couch near the window. I like to stand at the bar table near the kitchen.

Each location provides different light conditions. Each location makes your eyes fatigue in a different way. The first thing that can help you is the brightness and contrast adjustment of your monitor. With normal conditions I set up my contrast and brightness to only 30% of the maximum level. 100% is used only on the direct sun on the balcony.

Sometimes screen adjustments are simply not enough. In these cases it is a good idea to use high and low contrast themes. High contrast for a sunny place and the low one in the dark.

Using vim you can do that without restarting the program. Go to normal (command) mode by pressing CTRL + C and type:

:colorscheme <name of the scheme>

Great color scheme for working in the dark and normal lightning is codeschool and zellner is handy for the light places.

Weekly Digest 14

2013-05-20T00:00:00Z

Previously on chodounsky.net

Don’t Flood Your Twitter - Schedule!

The best links from community

Rent-a-coder hilarity - Will Benton
Clickjack attack – the hidden threat right in front of you - Troy Hunt
Applying Conway’s Law - Phil Haack
Parallelism and concurrency need different tools - Yossi Kreinin
Using bit fields in C# - Filip Ekberg
Hack yourself first – how to go on the offence before online attackers do - Troy Hunt
What Every Programmer Should Know About Memory - PDF - Ulrich Drepper
Spot the defect: rounding, part two - Eric Lippert
The Dangers of Book Learnin’ - Dave Fecak
Programmers VS Hackers - Zigoo0
The CORRECT Way to Code a Custom Exception Class - Doug Seelinger

Interesting projects are

Android Studio

And finally more great link collections

Dew Drop - Alvin Ashcraft’s Morning Dew,
The Morning Brew - Chris Alcock,
The Daily Sixpack - Dirk Strauss,
Interesting Finds - Jason Haley.

Don't Flood Your Twitter - Schedule!

2013-05-15T00:00:00Z

I read a lot of blog posts. As most of you probably know, I digest these posts for you, dear reader, in weekly programming digests - and if you didn’t know, go and check them out.

Each day I post articles I liked on Twitter. That means multiple links per day. I used to send my links through email and submit them before the dinner to Twitter in a batch.

One of my friends was complaining that I flooded his wall. Every tweet he saw was from me when I decided to do the batch. This is definitely not a good thing. I am very glad he didn’t remain silent and he told me what bothers him. Criticism is always a good thing and you should learn from your mistakes.

This batch approach, apart from it can drive some people mad and make them unfollow you, has a few other disadvantages too. If someone misses your batch you are invisible. There is no evidence of your virtual presence and activity. And you will become invisible for users from different timezones.

So I started to think, how to solve this problem. There must be some way to schedule your tweets. My requirements were simple. I wanted to schedule my tweet to a given time, I wanted an extension for Chrome and I wanted to be able tweet from my android phone and tablet.

I found a great application (or more likely a platform) that satisfies all my requirements and gives me much more features called Buffer.

How Does It Work?

You simple sign with your Twitter account. You can use Facebook, LinkedIn or a custom one. Buffer works with these social platforms too but they are not on my radar.

After signing you download a browser extension - Chrome, Firefox and Safari are supported. Or you can install application for your phone. Currently iPhone and Android are supported.

When you find a site that is remarkable for sharing, like chodounsky.net of course, you click on the buffer extension button in the top right corner and click Buffer. Link shortening is handled for you by Buffer worry about the length of the URL. For shortening you can choose bit.ly or use the one provided from Buffer.

You can set up your custom schedule when to post your tweets.

And if you use service for link shortening there are simple statistics that can track the performance of your links.

Mobile version uses the Share button on your phone. Therefore you can add content to buffer from every application that supports sharing. I use it with my mobile browser and the mobile version of feedly. And it works just great.

Conclusion

Buffer is a great application for managing your tweets and social activity in general. It is free for basic usage and the basic features are everything you should need. You should never flood your follower’s walls again.

You can use it with your browser or smartphone. Great tool!

Weekly Digest 13

2013-05-13T05:07:03Z

Previously on chodounsky.net

Merge Files with Git Merge Tool

The best links from community

Git Branching and Forking in the Enterprise: Why Fork? - Nicola Paolucci
Big-O Cheat Sheet
Producing permutations, part seven - Eric Lippert
Why I am the world’s greatest lover (and other worthless security claims) - Troy Hunt
Four ways of passing data between layers - Shivprasad koirala
Rerun: I have a mysterious fifth sense - Eric Lippert
Math ∩ Programming - Primers - Jeremy Kun

And finally more great link collections

Dew Drop - Alvin Ashcraft’s Morning Dew,
The Morning Brew - Chris Alcock,
The Daily Sixpack - Dirk Strauss,
Interesting Finds - Jason Haley.

Merge Files with Git Merge Tool

2013-05-09T13:45:19Z

Last time I wrote about git diff and difftool and showed you how to use them to compare different files and versions. Today I am going to focus on the merging and conflict resolution with git merge and mergetool. Merging is an important part of the development process. If you use git you probably work with multiple branches. But even if you develop in trunk with more people, merging and the conflict resolution comes in place when two are working on the same file.

Merge Tool

Mergetool is a command in git that lets you run your custom tool for resolving conflicts in your merged files. Let’s setup the tool and take a closer look at the basic usage.

Setup

We will use p4merge as we already use it for a difftool. It is a great tool with a lot of extra features and very good performance.

For setting up p4merge as your mergetool you have to run these commands.

git config --global merge.tool p4merge
git config --global mergetool.prompt false
git config --global mergetool.p4merge.cmd  '\"C:/Program Files/Perforce/p4merge.exe\" $BASE $LOCAL $REMOTE $MERGED'
git config --global mergetool.p4merge.keepTemporaries false
git config --global mergetool.p4merge.trustExitCode false

Usage

So you’ve set up your tool. Let’s resolve our first conflict that I created. I have two branches. Master and iss1. I created file called test.txt in both of them. The content of the file in master branch is master and the content in the iss1 branch is iss1. I committed those changes and now I am trying to merge iss1 into master branch. I ran git merge iss1 command. Take a look at the output.

C:\Users\Jakub\Desktop\ruby-sample [master]> git merge iss1
Auto-merging test.txt
CONFLICT (add/add): Merge conflict in test.txt
Automatic merge failed; fix conflicts and then commit the result.

Merge couldn’t be performed automatically and manual resolution comes into place. Now we run the mergetool command.

git mergetool

P4merge tool starts right away.

You can see that p4merge supports three-way merge. Resolve the conflict and save the file.

Branches were successfully saved. You can notice git created *.orig file with the content from both branches - test.txt.orig. If you’d like to remove this file after merge automatically you have to disable mergetool backups.

git config --global mergetool.keepBackup false

Conclusion

This article gave you a quick introduction to merging with git. You set up p4merge as your primary mergetool and you are able to use it for any conflict resolution.

Weekly Digest 12

2013-05-06T00:00:00Z

Previously on chodounsky.net

Compare Files with Git Diff Tool

The best links from community

Train Loop - xkcd
Pair Programming and a Grass-Roots Movement - Scott Leberknight
Producing permutations, part five - Eric Lippert
So You Don’t Want to be a Programmer After All - Jeff Atwood
Entity Framework Code First Inheritance - Ricardo Peres
Entity Framework Code First Relations - Ricardo Peres
Myth: Eric Brewer On Why Banks Are BASE Not ACID - Availability Is Revenue - Todd Hoff
Git Explained: For Beginners - Juri Strumpflohner
Producing permutations, part six - Eric Lippert
Social Authentication in ASP.NET MVC 4 - Dino Esposito
My Thoughts on Work/Life Balance at Microsoft - Jon Gallant
McDonald’s Theory - Jon Bell
Limiting Parallelism with Parallel.Invoke - Richard Carr
Evil assumptions - Eric Brechner
Damn Cool Algorithms, Part 1: BK-Trees - Nick Johnson
Legacy Code Preservation: Paving the Cowpaths - Steven Lott

Interesting projects are

mruby web irb - web interactive ruby interface
ruby2-rails4-bootstrap-heroku - A Starter Application based on Ruby2 Rails4 and Twitter Bootstrap, deployable on Heroku

And finally more great link collections

Dew Drop - Alvin Ashcraft’s Morning Dew,
The Morning Brew - Chris Alcock,
The Daily Sixpack - Dirk Strauss,
Interesting Finds - Jason Haley.

Compare Files with Git Diff Tool

2013-05-01T13:44:50Z

Comparing files under your version control system is one of the most common tasks in programming. This article describes techniques that are available in git. It helps you setup git diff tool and shows you how to use it to perform some basic comparisons of your changes to a current base and also few more advanced comparisons between specific commits.

Diff

Git already comes with the tool for file comparison. It is text based and easy to use with files with few line changes.

Changing Colors

If you use git on Windows especially with Powershell and posh-git extensions you soon realize that some colors in the output are very hard to read. The dark red used with git status and displayed changes doesn’t work very well with the blue background.

For changing git global configuration of modified and untracked files you need to run these commands. Let’s change the color from dark red to cyan and also modify the colors for changes to more shiny ones.

git config --global color.status.changed "cyan normal bold" 
git config --global color.status.untracked "cyan normal bold"
git config --global color.diff.old "red normal bold"
git config --global color.diff.new "green normal bold"

Posh-git is a great tool but the information about modified, untracked and removed files aren’t readable. We’ll change it to much better colors. You have to edit your Powershell profile that is located in your documents folder and you can run $profile to see where exactly it is. Add the following lines to the end of the file and it changes the output from dark red to yellow.

$global:GitPromptSettings.WorkingForegroundColor = [ConsoleColor]::Yellow 
$global:GitPromptSettings.UntrackedForegroundColor = [ConsoleColor]::Yellow

Now the output in the Powershell window is much more readable. Take a look at the screenshot and compare it with the previous one.

This looks much better than the previous one, don’t you think?

Usage

The most simple usage is to run the command without any parameters.

git diff

It displays all the differences in all your modified files from previously committed work. Old lines are prefixed with the - sign and the new lines with the + sign. There is many more information in the output and I recommend to take a look at stackoverflow for their representation. Just be aware that some of them are not available in the msysgit implementation on Windows.

For displaying the difference in just one file you have to add the file relative location and the file name.

git diff location\filename

Difftool

If you are not satisfied with the simple text diff you need to use a custom tool. For this purpose git provides a command difftool. It allows you to register comparison tool of your choice and to integrate it with git.

Setup

The tool of my choice is p4merge. It is a free, fast and it is capable of performing the most challenging merging and comparing tasks.

There is a lot of different tools you can use and each setup would be a little different. Next steps show you how to setup p4merge as git difftool.

git config --global diff.tool p4merge
git config --global difftool.p4merge.cmd 'p4merge.exe $LOCAL $REMOTE'
git config --global difftool.prompt false

P4merge must be added to your system path. Otherwise you have to provide the full path to the exe file in the difftool.p4merge.cmd line.

That’s it. From now on p4merge is ready to compare your files. Let’s try it with comparing the working file against the revision in repository. The usage is similar to the git diff from above.

# Starts git difftool for all modified files
git difftool

# Compare only specific file
git difftool location\filename

The first command runs the difftool for all modified files and the second one compares only the specified file.

Advanced Usage

The first thing we want to do is to compare file against specific revision. You can list file revisions with the git log command.

git log filename

From the output you can copy the commit identifier and run the difftool with the path to the version you want to compare with. Just like this.

git difftool 8d53363981a35c07f2bee7cae71f8e8bd95be625 -- filename

You can also compare between two different commits with the following syntax.

# git difftool [start commit]..[end commit] filename
git difftool 6cde26245763dd43f9505c7578a1f7be44b7fad1..8d53363981a35c07f2bee7cae71f8e8bd95be625 filename

You can specify the path of the revision to the branch, relatively to the number of history commits and in more other ways you can ever dream about. Also don’t forget that you can use graphical tools for displaying the history of the file like gitk and others.

Conclusion

Your git should be set up to use diff tool p4merge. With the changed colors you receive much better experience from your command line output.

After reading this article comparison of two different files and looking for changes between different revisions and branches should be no mystery for you. If you have any suggestions to make this experience even more pleasant, please leave a comment.

Weekly Digest 11

2013-04-29T00:00:00Z

Previously on chodounsky.net

Nanoc Project Structure

The best links from community

Immutable Data and Memoization in C#, Part 1 - Jérôme Laban
Producing permutations, part three - Eric Lippert
Better Testers - Phil Haack
Exposed: A Blog Comment Spammer’s Source Template - Scott Hanselman
More on Immutable Collections in .NET - Jonathan Allen
Inside Portable Class Libraries - Simon Cooper
Ten reasons not to use a statically typed functional programming language - scottw
Introducing: Code Digger, an extension for VS2012 - Nikolai Tillmann
Legacy Code Preservation: Are There Quirks? - Steven Lott
Understanding IntelliTrace Part I - zainmab
Are you coding for change or stability - the followup post - Marcus Hammarberg
Immutable Data and Memoization in C#, Part 2 - Jérôme Laban
Stop Your Console App The Nice Way - Mike Hadlow
Sleep: Everything You Need To Know - Maroun Najjar
Functors, Applicatives, And Monads In Pictures - Aditya Bhargava
Permutations, part four - Eric Lippert

Interesting projects are

Garmoshka - CSS3 responsive design project
Dynamic Lambda Expression Compiler - Fernando Callejon

And finally more great link collections

Dew Drop - Alvin Ashcraft’s Morning Dew,
The Morning Brew - Chris Alcock,
The Daily Sixpack - Dirk Strauss,
Interesting Finds - Jason Haley.

Nanoc Project Structure

2013-04-23T00:00:00Z

In the previous part of the series we created a simple hello world application and fixed problems with the encoding. This part guides you through the nanoc project structure and gives you better understanding how the web site is linked together.

There are multiple files and folders in the project structure.

|- content/
|- layouts/
|- lib/
|- output/
|- tmp/
|- nanoc.yaml (config.yaml)
|- crash.log
|- Rules

content/: contains uncompiled data for your web site
layouts/: all your templates are placed here
lib/: helper functions, extensions and all your custom ruby code
output/: compiled web site prepared for deploying to server
tmp/: temporary files used for speeding up the compilation
nanoc.yaml: site configuration, in the older versions this file is called config.yaml
crash.log: if your compilation fails the error is logged in this file
Rules: contains a set of rules how to treat your content files

Let’s take a closer look to the important items in the hierarchy.

Rules

This file is the most essential file in the nanoc generator. Rules are used for two different important purposes - compilation and routing. To be technically precise there is a preprocessing before compilation. It can be used for advanced techniques like pagination but we are going to skip this process to keep it simple.

Compilation

Compilation determines how specified files should be treated when compiled by nanoc. You can set filters and assign layouts.

Filters are used for content transformation. You can chain multiple filters together. Typical example is to compile your pages written in markdown with the kramdown filter.

compile 'posts/*' do
    filter :kramdown
end

In this example all the files in the posts directory are compiled with the kramdown filter.

You can use advanced code in the compile body. For example you can compile your files based on extension.

compile '*' do
    if item.binary?
        # don’t filter binary items
    else
        case item[:extension]
            when 'md'
                filter :kramdown
                layout 'default'
            when 'erb'
                filter :erb
                layout 'default'
        end
    end
end

No filter is set for binary items. Items with *.md extension are compiled with kramdown filter and items with *.erb extension are treated as erb files.

The layout property is used for choosing proper template. Templates are stored in the layout folder and this is how they are assigned to items from the content folder. You can use special template for all your blog posts and default template for normal pages. Next example shows you how to do it.

compile 'posts/*'
    layout: 'post'
end

compile '*'
    if item.binary?
        # don’t filter binary items
    else
        layout: 'default'
    end
end

Keep in mind that you should start with the most specific rules. Rules ordering matters. If you put general rule for ‘*’ to the top of your file all other rules are skipped.

compile '*' do 
    ...
end

compile 'post/**' do 
    // this rule won't be applied because it is 
    // placed in this file after more general one
end

Filters can be also very useful for binary files and your resources. Imagine that you can create thumbnails from your images for your custom gallery. Or you want to write your CSS with LESS and then use minification. All these things are possible with nanoc.

Routing

The second important part of the Rules file is routing. These rules are used to determine the physical representation of the output of compiled content. In other words it says where the file would be placed on your web server.

As with the compilation rules routing ordering also matters so you should keep the general ones at the bottom.

Routing can be used for ignoring output from specific folders. Let’s say we have a draft folder. If you don’t set the route body the output is ignored.

route 'posts/drafts/*' do 
end

Another usage of routing is the way to create cleaner URLs for non binary items.

route '*' do
    if item.binary?
        # Write item with identifier /foo/ to /foo.ext
        item.identifier.chop + '.' + item[:extension]
    else
        # Write item with identifier /foo/ to /foo/index.html
        item.identifier + 'index.html'
    end
end

Layout

We already discussed how the layout files are assigned with Rules file. The file with the assigned name (without extension) must exist in the layout folder. Layout file is a HTML template with special tag <%= yield =>. After compilation the tag is replaced by current content.

<html>
<head>
    <title>Hello World</title>
</head>
<body>
    <%= yield =>
</body>
</html>

You can create partial views. They can be nested together. This feature is very useful especially when you have a global view and few special nested views like gallery, post or project view.

<% render "default" do %>
    <h2>Other view</h2>
    <div>
        <%= yield =>
    </div>        
<% end %>

In the example above the view is placed in the file called default.erb instead of the yield and current compiled content is placed instead of the yield in this partial view.

Configuration

The global configuration of your web site is located in the nanoc.yaml or config.yaml in older version of nanoc. In our default hello world application it contains information about supported text extensions, automatic watcher and some other global settings.

You can change output directory of your site by modifying the output_dir: output to another value.

It is not necessary to change those settings for creating basic applications but you can add your own.

title: 'chodounsky.net - Jakub Chodounsky'
author_name: 'Jakub Chodounsky'
author_uri: 'http://www.chodounsky.net'
base_url: 'http://chodounsky.net'

Helpers and Custom Functions

Helpers are pieces of ruby code that you can use in your layouts and items. Location for your custom helpers is in the lib folder.

By default there is a file called default.rb. Nanoc comes with a set of integrated helpers but they need to be activated before using. This can be done very easily.

include Nanoc3::Helpers::Blogging
include Nanoc3::Helpers::Tagging
include Nanoc3::Helpers::Rendering
include Nanoc3::Helpers::LinkTo

If you want to write custom code you can do it in the default.rb or you can create new files and link modules together in the default.rb.

Conclusion

After reading this article you don’t have to search anymore where to put your content and where to modify necessary files. Now you should have a good starting point for creating custom web site with nanoc.

In the next article we will focus on the blogging features and how nanoc can be an effective tool that won’t stand in your way.

Weekly Digest 10

2013-04-22T00:00:00Z

The best links from community

Date and Time Data Types and Functions - Shemeer NS
Installing Helvetica Neue Fonts with Google Chrome on Windows considered harmful - Scott Hanselman
Are you coding for change or for stability? - Marcus Hammarberg
Producing permutations, part one - Eric Lippert
Producing permutations, part two - Eric Lippert
Why Do People Hate Their Jobs? - James Altucher
You should blog even if you have no readers - Nathan Marz

And finally more great link collections

Dew Drop - Alvin Ashcraft’s Morning Dew,
The Morning Brew - Chris Alcock,
The Daily Sixpack - Dirk Strauss,
Interesting Finds - Jason Haley.