http://railsblog.ainakatani.com

Because I use layout ‘application‘, by default, all of the pages’ title, keywords, and description were same as specified in layouts/application.html.erb

I wanted to show a baby name on the browser tab (title) so that when the multiple pages are open on tabs, the users will know which page is on which tab. Bookmarking would also be easier.

I found this article by SEO on Rails very useful: Getting your meta tags on track

Now each of the name pages has a unique title.  Also, when you click on a flag, the new page title also contains the region name.

<%= objects.map(&:attribute).join(‘, ‘) %>

For example, if I want to output a string consisting some objects(say babynames)’ names, I write:

<%= babynames.map(&:name).join(‘, ‘) %>

The output will be something like:

Andrew, Chris, Oliver, Anna

This is nice because you don’t have to write a loop and check whether to add a comma (or period or whatever) after each name.

(If you want to see the example, please visit the entry form here and type a name ‘Ai’ which already exists in the database)

I read this article at SciWerks.com and changed the code here and there so that a newbie like me can understand it easily.

I have a model called babyname, and it has name as an attribute.

Here is what I did:

In my babyname  ‘new’ view file, I had the following code inside the entry form:

<%= text_field_with_auto_complete :babyname, :name %>

<div id=‘name_error‘></div>

And in my controller, I put the following code:

def auto_complete_for_babyname_name

@babyname = Babyname.find_by_name(params[:babyname][:name])
if @babyname

render :update do |page|

page.replace_html ‘name_error’, link_to(‘Name is already registered. Click here to view the details.‘, @babyname)

end

else

render :update do |page|

page.replace_html ‘name_error‘, “”

end

end

end

That’s it. As the user types a character, it checks whether the string matches any name in the babynames table. If the name is found, then it shows (insert) the error message (at <div></div> tags) as a link to that name page. If not, it shows an empty string (that is, no error message).

If you don’t want to have a link and want to show only the error message, you can replace one line of code with this:

page.replace_html ‘name_error‘, “Name is already registered“

You can also use this technique to ensure the uniqueness of user ID, email address, etc. like I did on this page.

What if you don’t want any subdomains? What if you want your Rails project to run on the main domain itself (for instance, http://www.mixedbabyname.com)?

I asked HostMonster support and got the following answer (they were nice enough to do it themselves and let me know what they did!)

I renamed public_html to public_html-old.  I then ran this command:

> username@domain.com [~]# ln -s ~/rails/project_name/public public_html

This created a symlink for your main domain to the public folder of the project_name rails app.  Now, when visiting http://mixedbabyname.com , it pulls up your rails app automatically.

These guys are so nice

Then I signed up for my HostMonster account, got the domain and transferred all of my data, and BOOM! All of my Japanese character strings in the database became a bunch of random characters.

By default, the character set for HostMonster’s MySQL database is latin1. Try this command to see the settings:

> show variables like ‘character_set%’;

I tried to change them, but I couldn’t. I was stupid enough to ask  HostMonster support to change the settings and got the following response: “Those variables will not be modified on the root because other clients on this shared server are dependent on these settings being constant.”

However, we can change the settings for our own database (HostMonster’s Response):

You can set the collation of the table to use a specific Character Set.  Log into the cPanel and click the phpMyAdmin.  Right column, select the database’s name and then the table name where this data is stored.  Click the Operations tab along top and find the drop-down list to select the desired collation for the language you use. Alternatively, you may run the SQL command such as

> ALTER DATABASE databasename CHARACTER SET utf8 COLLATE utf8_general_ci;

One thing to note is that you MUST change the character set of the database before making any tables and columns.

The tables and columns settings (yes, each table and column has its own character settings) depend on the database settings at the time of the creation.

So, if you already made tables and columns and wish to change the entire settings, I propose that you drop all of the tables, change the database settings, and then re-create tables and transfer all of the data.

I speak Japanese, so most of my websites need to show Japanese characters.

Before making a Japanese website, you have to create the following environment:

• Operating System – Your computer should be able to show and type Japanese characters  (I use Windows XP’s English version, so I had to install Asian characters on my computer in order to read and write Japanese. Go to Control Panel )

• Development software – Your text editing software or any software you use to create website must have Japanese character sets. These days most of the software  do.  Back in old days, I could count the number of text editing software that was made in English yet could read/write Japanese!
• Server – Make sure your database’s character set is UTF8 or some other character set that can properly store the language you are intending to use.

I forgot to set “cascade delete” to my tables.  So, when I deleted an entry, the dependents’ records associated with that entry remained in the database.  In other words, these records became orphans. They have a foreign key which no longer exists. This can throw an error when I access the children table and try to use this foreign key to get the deleted parent’s information.

Say, we have two tables: parents and children.  The children table belongs to the parents table, so the children table has a column called parent_id, which is associated with the unique id in the parents table.

This command looks for orphans’ deceased parents’ ids.

> select parent_id from children where parent_id NOT IN(select id from parents);

If this returns an empty set,  there is no orphen.

Alternatively, you can also do this to simply  look for the orphans’ ids.

> select id from children where parent_id NOT IN(select id from parents);

>ruby script/console

To check if it’s working,  just type something like:
>Tablename.find(:all)

This should show all of the entries in that table.