這兩個有什麼不同?
<% ... %>
執行後印出內容，包括你原始碼的空白與換行。
<% ... -%>
除了印出內容外，會削掉多餘的換行。
拿個例子來解釋:
輸出的html結果是:
---
空一行
hello world
空一行
空一行
hello world
空一行
空一行
---
改成<% 2.times do -%>
結果是:
hello world
hello world
Well, I hate being bothered by these encoding issues!
I develop a ror website with my TextMate. And the problem is always client's favorite encoding characters: Big-5. Yes, I love Chinese characters. However, TextMate encode rhtml file with UTF-8. Though I could type well Chinese words on the file.
After browser's gestures, those letters are broken all the time! So, I must code with Textmate AND write rhtml with Dreamweaver. It make me confused sometimes. @@
Not only database collation is big-5 but also the file database.yml has to add line:
encoding:Big5
Due to my working project, I have to export some popular file format for the clients to download. Like PDF,Excel,Word ... , I made some surfing and I found:
ActionController has a key attribute:
"request"
which contains all http header attributes.
i.e:
def server_ip
location = request.env["SERVER_ADDR"]
render :text => "This server hosted at #{location}"
end
To get root host url, type: request.env["HTTP_HOST"]
more useful key attributes in ActionController:
Go Deprecations at rubyonrails.org
由於 Ruby on Rails 正在快速發展中，推陳出新之後，陳舊的語法就必須拋棄或改寫，除此之外，也要注意書本上的寫法，是不是已經過時了。
[reference: Programming Ruby 2nd]
Some languages feature keyword arguments—that is, instead of passing arguments in a given order and quantity, you pass the name of the argumentwith its value,in any order.
Ruby 1.8 does not have keyword arguments. In the meantime, people are
using hashes as a way of achieving the same effect.
class SongList
def create_search(name, params)
# ...
end
end
list.create_search("short jazz songs",
{
'genre' => "jazz",
'duration_less_than' => 270
})
The first parameter is the search name, and the second is a hash literal containing search parameters. The use of a hash means we can simulate keywords: look for songs with a genre of “jazz” and a duration less than 4 12 minutes. However, this approach is slightly clunky, and that set of braces could easily be mistaken for a block associated with the method. So,
Ruby has a shortcut. You can place key => value pairs in an argument list
, as long as they follow any normal arguments and precede any array and block arguments.
All these pairs will be collected into a single hash and passed as one argument to the method. No braces are needed.
list.create_search('short jazz songs',
'genre' => 'jazz',
'duration_less_than' => 270)
Finally, in idiomatic Ruby you’d probably use symbols rather than strings, as symbols
make it clearer that you’re referring to the name of something.
list.create_search('short jazz songs',
:genre => :jazz,
:duration_less_than => 270)
A well-written Ruby program will typically contain many methods, each quite small,
so it’s worth getting familiar with the options available when defining and using Ruby
methods.
安裝:(Ruby Gem )
$ gem install merb -y
建立專案:
$ merb -g myapp
Merb的檔案結構:
merb_app:
Rakefile
README
scripts
test
spec
unit
plugins
dist
app
controllers
models
views
conf
lib
public
plugins
schema
Well, It was a disaster before. Trying to type chineses characters quickly kills your processes. I have encountered this situration so many time. So I was very carefully writing codes.
But, someone came to solve it.
library/font
CJK-Input.tmplugin
Preference/font&color ,change the font to 'TextMateJ'