CarrierWave, an alternative to PaperClip for Uploading Files in Rails or Ruby Applications

I recently switched to CarrierWave: "Classier solution for file uploads in Ruby for Rack, Rails, Merb and Sinatra". Why? Here's three reasons:

1. Uploading logic/handling is extracted into a separate class. Hence the tag "Classier solution". It addresses my sensibility for Single Responsibility and separation of concerns.
2. It maintains a cache across redisplays. Meaning the user does not need to upload a file again, if other fields are invalid on the model.
3. Dead easy upload from a remote URL.

Definitley give it a try. Anything I have missed? Let me know in the comments.

Redmine Estimated Time Summary Plugin

Redmine doesn't provide any summaries/totals for time estimated on issues out-of-the-box. If this is what you need, I highly recommend redmine_estimated_summary plugin.

Rail's ActiveRecord: include vs join

Confused when to use the :include vs. :join option? Remember these points:

• join does not load the association into association
• include does, it loads each association into memory
• include is not compatible with select option
• use include when the association is referenced
• example use with join, doing a dynamic count on an association
• or when the association is not referenced

ActiveRecord::Base#becomes

An ActiveRecord method I did not existed: becomes.

Returns an instance of the specified klass with the attributes of the current record. This is mostly useful in relation to single-table inheritance structures where you want a subclass to appear as the superclass. This can be used along with record identification in Action Pack to allow, say, Client < Company to do something like render :partial => @client.becomes(Company) to render that instance using the companies/company partial instead of clients/client. Note: The new instance will share a link to the same attributes as the original class. So any change to the attributes in either instance will affect the other.

Web Integrator Application Hand-off Checklist

One scenario in developing applications, is the application is built and then handed off to a Web Integrator to implement the CSS. The other is templates are created and these are integrated by the web developer. This checklist is primary for the first scenario, but is probably applicable to the second. Here is a list of checks you should make before handing off for integration:

• Demo data: Can the web integrator easily add demo data to the application. This should be done via a script.
• Translation: If your application is multi-lingual, ensure all strings are in a locale file and the Web Integrator knows how to edit these. Spend some time teaching the Web Integrator on how it works.
• Test translations: Before an application is translated, run the application in the secondary language to make sure that all "strings" for that language are missing. Check especially for emails static pages and built-in error messages, labels and attributes.
• Language Switcher: Ensure a language switcher exists and is working.
• Emails: If your application sends emails, ensure the developer can send and preview these easily. This can be done with the a script to send emails and a preview option via http. Rather than your application send emails, use a email service provider.
• Minimize custom helpers: Helpers can be a roadblock for a Web Integrator not familiar with Rails. If you do use helpers, have the helper render a partial which can be easily customized.
• Test accounts: Most applications are not standalone these days. If your application connects with external services such as Twitter and Youtube, ensure test accounts have been setup and can easily be used. You want to encourage the Web Integrator to use these integrations as much as possible. It's a great way to catch bugs!
• Overlay option: Seen a web site without an overlay these days? Allow your Web Integrator to render a page without the entire layout easily. Passing a parameter along the URI is great way to do this.

Any thing I have missed? Please let me know in the comments.

Rails UJS using jQuery results in Unknown File Type/Prompted to save file with IE

I'm developing a Rails 2.3 project with the UJS file for Rails 3. Instead of the remote_form_fortags, I'm adding the data-remote attribute. This was running great on Safari and Firefox, but testing a form post on IE would result in the browser trying to save the file. There are a lot of posts regarding this issue, but none of them worked for me.

The fix ended up being very simple. Upgrade jQuery. The application was using 1.4.2. I upgraded to 1.4.3 and everything worked as it should under IE.

Related posts

• Rails UJS rendering js.erb template in IE
• Internet Explorer blocked file download; file of “Unknown File Type”
• IE throws “File Download Security Warning” on form submit
• Rails’ respond_to method

Unix History Commands

!! : to run the previous command 
^P : move up through history list, one command at a time. (Up arrow key) 
^N : move down (or Down arrow key). 
!n : run nth command in history list. where n is a number from your history list. 
!n:p : only preview command number n (will not execute the command). 
!string : Run most recent command starting with characters in st

Source