Technology Insights

Setting up BackgrounDrb

I decided to use BackgrounDrb 0.2.1 to launch a periodic task that would run every 15 seconds.Warning: After going through the hassle of setting up BackgrounDrb, I found out that it isn’t even supported in Windows (my dev environment)! See step 8. So, these instructions haven’t been fully tested yet on a *.nix environment. Good…

Technology Insights

Ruby on Rails File Upload Plug-ins

Basically, I dug up 5 plug-ins (plugins) that can do the job 1. acts as attachment 2. attachment_fu (extension of act_as_attachment) I used Khamsouk’s tutorial (but without the AJAX) and had to change the following line from :max_size => 1.megabytes to :size => 0.megabyte..1.megabytes Mike Clark also has a good tutorial, but he doesn’t use…

Technology Insights

What Exactly Does the Scaffold_Resource Generator give you?

The regular scaffold generator (e.g. ruby script/generate scaffold model controller) requires you to create your model and controller first. The scaffold_resource generator, on the other hand, generates the (RESTful) model and controller for you. For example: ruby script/generate scaffold_resource Caregiver first_name:string last_name:string In Rails 2.0, use resource instead: ruby script/generate resource Caregiver first_name:string last_name:string Here’s…

Technology Errors

“Multiple Default Values” Migration Error with PostgreSQL 8.2.5

PostgreSQL 8.2.5 error == CreateHeartrates: migrating ================================================ — create_table(:heartrates) NOTICE: CREATE TABLE will create implicit sequence “heartrates_id_seq” for serial column “heartrates.id” rake aborted! PGError: ERROR: multiple default values specified for column “id” of table “heartrates” : CREATE TABLE heartrates (“id” serial primary key DEFAULT NULL, “user_id” integer DEFAULT NULL, “timestamp” timestamp with time zone DEFAULT…

Technology Insights

View for Version Numbers, Hostnames, IPs, Etc.

Here’s some code (and rendered view) for various version numbers, host names, IPs for Ruby, Rails, PostgreSQL, SMTP. <b>Network</b><br> UNIX hostname: <code><%= `hostname` %></code><br> SERVER_ADDR: <code><%= request.env[“SERVER_ADDR”].to_s %></code> <br> HOST_NAME : <code><%= request.host %></code> <br> REMOTE_ADDR: <code><%= request.env[“REMOTE_ADDR”].to_s %></code> <br> <br> <b>Software</b><br> Database: <code><%= ActiveRecord::Base.connection.select_value(“SELECT  VERSION()”) %></code><br> Email delivery method: <code><%= ActionMailer::Base.delivery_method %></code><br> SMTP server:…

Technology Insights

User Profiles with Restful Authentication

  Error when updating the user from a form ActiveRecord::RecordInvalid (Validation failed: Password confirmation can’t be blank, Password is too short (minimum is 4 characters), Password can’t be blank):       Suggestion It’s probably because of the restrictions on the User model (attr_accessible or attr_protected, in particular). But allowing users access to any part…