Migrations in Rails 2.1

Migrations in Rails 2.1
有跑過的migration, 會紀錄在schema_migrations 裡
強化了一些change column的功能
<br /># in a migration file<br />def self.up<br /> change_table :products do |t|<br /> t.rename :released_on, :released_at<br /> t.change :description, :text, :limit => nil, :null => true<br /> t.remove :price<br /> t.integer :stock_quantity<br /> end<br />end<br /><br />def self.down<br /> change_table :products do |t|<br /> t.rename :released_at, :released_on<br /> t.change :description, :string, :null => false<br /> t.decimal :price, :precision => 10, :scale => 2<br /> t.remove :stock_quantity<br /> end<br />end<br />

Non Active Record Model

Non Active Record Model
<br /><br /><br /># models/letter.rb<br />class Letter<br /> attr_reader :char<br /> <br /> def self.all<br /> ('A'..'Z').map { |c| new(c) }<br /> end<br /> <br /> def self.find(param)<br /> all.detect { |l| l.to_param == param } || raise(ActiveRecord::RecordNotFound)<br /> end<br /> <br /> def initialize(char)<br /> @char = char<br /> end<br /> <br /> def to_param<br /> @char.downcase<br /> end<br /> <br /> def products<br /> Product.find(:all, :conditions => ["name LIKE ?", @char + '%'], :order => "name")<br /> end<br />end<br /><br /># letters_controller.rb<br />def index<br /> @letters = Letter.all<br />end<br /><br />def show<br /> @letter = Letter.find(params[:id])<br />end<br /><br /><br /><br /><br /><!-- letters/index.html.erb --><br /><% title "Select a Letter" %><br /><br /><% for letter in @letters %><br /> <%= link_to letter.char, letter %><br /><% end %><br /><br /><!-- letters/show.html.erb --><br /><% title "Products for Letter #{@letter.char}" %><br /><br /><p><%= link_to "Select a Letter", letters_path %></p><br /><br /><%= render :partial => @letter.products %><br />

Going Back

<br /># cart_items_controller.rb<br />def create<br /> current_cart.cart_items.create!(params[:cart_item])<br /> flash[:notice] = "Product added to cart"<br /> redirect_to :back<br />end<br /><br /># or<br /><br />def create<br /> current_cart.cart_items.create!(params[:cart_item])<br /> flash[:notice] = "Product added to cart"<br /> session[:last_product_page] = request.env['HTTP_REFERER'] || products_url<br /> redirect_to current_cart_url<br />end<br /><br /><br /><!-- carts/show.html.erb --><br /><% if session[:last_product_page] %><br /> <%= link_to "Continue Shopping", session[:last_product_page] %> |<br /><% end %><br />

Helpers Outside Views

Helpers outside views
<br /># models/category.rb<br />def description<br /> "This category has #{helpers.pluralize(products.count, 'product')}."<br />end<br /><br />def helpers<br /> ActionController::Base.helpers<br />end<br /><br /># products_controller.rb<br />def create<br /> @product = Product.new(params[:product])<br /> if @product.save<br /> flash[:notice] = "Successfully created #{@template.link_to('product', @product)}."<br /> redirect_to products_url<br /> else<br /> render :action => 'new'<br /> end<br />end<br />

JSON

<br />>> ActiveSupport::JSON.decode("{\"name\":\"a\",\"id\":\"1\"}")<br />=> {"name"=>"a", "id"=>"1"}<br /><br />>> ActiveSupport::JSON.encode({"name"=>"a", "id"=>"1"})<br />=> "{\"name\": \"a\", \"id\": \"1\"}<br />這個encode, decode 是ruby 做的<br /><br />還有C的json encode, decode gem 可以裝<br />

javascript tips

<br /> <[ form name ="myform"]>.....<[/form]><br /> //可以直接指定 event trigger 的 function<br /> document.myform.onsubmit = validateform<br />

改變 iframe 的 source

http://twpug.net/modules/newbb/viewtopic.php?post_id=7602
http://www.javaworld.com.tw/jute/post/view?bid=34&id=161191&sty=3
<br /><[iframe width="100%" scrolling="no" height="0" frameborder="0" id="fTradeLink" src="http://www.google.com.tw"/]><br /><br />#可以直接用 id 去拿<br /><[script]><br /> fTradeLink.location.href = "http://yahoo.com.tw";<br /><[/script]><br />

javascript in browser tips

1. window 是最上層的object, document 是其中的一個屬性
2. window 指的是視窗, frame, iframe, document 代表HTML 文件
3. example: parent.frames[0].documnet.forms[0].elements[3].options[2].text
4. javascript 不能跨網域使用, 但是指的並不是該javascript 的來源source, 而是嵌入, 用該javascript的地方

cookies 設定

cookies api
# :value - The cookie‘s value or list of values (as an array).
# :path - The path for which this cookie applies. Defaults to the root of the application.
# :domain - The domain for which this cookie applies.
# :expires - The time at which this cookie expires, as a Time object.
# :secure - Whether this cookie is a only transmitted to HTTPS servers. Default is false.
# :http_only - Whether this cookie is accessible via scripting or only HTTP. Defaults to false.

cookies 的一些觀念
1.要在這個domain 跟 path之下的才能拿, 例如如果把domain設成
ilake.demo.com, demo.demo.com 這樣彼此是不能拿的, 可是設成 demo.com 便可以

2. cookies 誰都可以寫, 寫就是寫了, https 寫的 http 也可以拿, 但是可以設成只有 https 才可以拿, :secure 就是此選項, 而http_only 便是javascript 不能拿

3.不能把cookie domain 設成你現在server domain 以外的 domain

4.navigator.cookieEnabled 可以檢查cookie 功能是否開啟

5.cookie 不能包含分號 逗號 空白, 所以有時妳會需要用encodeURIComponent, 讀取時就要使用相對應的decodeURIComponent

6.刪除cookie, 就是把他直接設過去的時間即可

7.cookie 只能有4K, cookie 在妳request 其符合規則網頁時(same domain, path etc...)
就算妳沒用它, 它也會上傳到server

---

另外 rails cookies 裡有 subdomain_fu 在localhost 這種 domain 之下, 有點問題, 把他弄成demo.com 這樣正常的domain, 便可以正常拿到該domain 下的cookies

javascript在網頁頁面加載時的執行順序

javascript在網頁頁面加載時的執行順序

javascript在頁面的執行順序

1、頁面上的javascript代碼是HTML文檔的一部分，所以javascript在頁面裝載時執行的順序就是其引入標記<[script /]>的出現順序， <[script /]>標記裡面的或者通過src引入的外部JS，都是按照其語句出現的順序執行，而且執行過程是文檔裝載的一部分。


3、變量的調用，必須是前面已經聲明，否則獲取的變量值是undefined。
<br /><[script type="text/javscrpt"]>//(![CDATA[<br />alert(tmp); //輸出 undefined<br />var tmp = 1;<br />alert(tmp); //輸出 1<br />//]]><[/script]><br />
5、document.write()會把輸出寫入到腳本文檔所在的位置，瀏覽器解析完documemt.write()所在文檔內容後，繼續解析document.write()輸出的內容，然後在繼續解析HTML文檔。
<br /><[script type="text/javascript"]>//(![CDATA[<br /> document.write('<[script type="text/javascript" src="test.js"]><\/script>');<br /> document.write('<[script type="text/javascript"]>');<br /> document.write('alert(2);')<br /> document.write('alert("我是" + tmpStr);');<br /> document.write('<\/script>');<br /> //]]>(/script><br /> <[script type="text/javascript"]>//(![CDATA[<br /> alert(3);<br /> //]]><[/script]><br />
test.js的內容是：

var tmpStr = 1;
alert(tmpStr);

在Firefox和Opera中的彈出值的順序是：1、2、我是1、3

在IE中彈出值的順序是：2、1、3，同時瀏覽器報錯：tmpStr未定義

原因可能是IE在document.write時，並未等待加載SRC中的javascript代碼完畢後，才執行下一行，所以導致2先彈出，並且執行到 document.write(』document.write("我是" + tmpStr)』)調用tmpStr時，tmpStr並未定義，從而報錯。

解決這個問題，可以利用HTML解析是解析完一個HTML標籤，再執行下一個的原理，把代碼拆分來實現：
<br /><[script type="text/javascript"]>//(![CDATA[<br /> document.write('<[script type="text/javascript" src="test.js"]><\/script>');<br /> //]]><[/script]><br /> <[script type="text/javascript"]>//(![CDATA[<br /> document.write('<[script type="text/javascript"]>');<br /> document.write('alert(2);')<br /> document.write('alert("我是" + tmpStr);');<br /> document.write('<\/script>');<br /> //]]><[/script]><br /> <[script type="text/javascript"]>//(![CDATA[<br /> alert(3);<br /> //]]><[/script]><br />
這樣IE下和其他瀏覽器輸出值的順序都是一直的了：1、2、我是1、3。

三、如何改變javascript在頁面的執行順序

1、利用onload
<br />(script type="text/javascript">//(![CDATA[<br />window.onload = f;<br />function f(){alert(1);}<br />alert(2);<br />//]]><[/script]><br />
輸出值順序是 2、1。

需要注意的是，如果存在多個winodws.onload的話，只有最有一個生效，解決這個辦法是：

window.onload = function(){f();f1();f2();.....}

ruby gzip, stringio

string io api
gzip api
我們想要壓縮一下sting, 可以用
<br /> #因為GzipWriter should be used with an instance of IO, or IO-like, object.<br /> #所以我們弄個StringIO來玩<br /> output = StringIO.new<br /> gz = Zlib::GzipWriter.new(output)<br /><br /> gz.write 'blahblah'<br /> gz.close<br /><br /> output.string #便是我們要的壓縮過後的string<br /><br /><br /> output = StringIO.new<br /> gz = Zlib::GzipWriter.new(output)<br /> gz.write(t.to_json)<br /> gz.close<br /> render :text => output.string, :content_type => 'application/x-gzip' and return<br /><br />

iframe 之間的互動

在一層又一層的iframe 裡, 我們可以利用 top 屬性直接跳到最上層的視窗操縱其他我們想操縱的 iframe

example
[ 內部 iframe]
<br /> $('#click_test').click(function(){<br /> top.lala();<br /> });<br />
[ 外部 iframe]
<br /> function lala() {<br /> $('.account').click();<br /> }<br />
當然為了各個iframe之間的溝通, 或許會有 same-origin policy 的問題
所以各個iframe 都需有將iframe 設成相同的 code, 例如很多使用subdomain 的 domain name
便可以如此使用
<br /> var sub = document.domain.split('.');<br /> sub.shift();<br /> sub = sub.join('.');<br /> document.domain = sub;<br />

textarea 點選自動複製, copy

<br />(textarea onclick="javascript:document.blogform.URL.focus();document.blogform.URL.select();<br />CopyToClipboard();" cols="40" rows="3" id="URL" name="URL")blahblah(/textarea)<br />

parent document

javascript 在要parent 時的這個parent 必須是在相同的 protocol, 跟 domain 下

get,submit

<br /> $('#functionBar .delete').click(function(){<br /> $("form:has('.alert_list')").get(0).submit();<br /> return false;<br /> });<br />

activerecord, query cache

query cache

<br /> User.find(1)<br /> User.find(1)<br /> User.find(1)<br /> User Load (0.000203) SELECT * FROM `user` WHERE (`user`.`id` = 1) <br /> User Load (0.000140) SELECT * FROM `user` WHERE (`user`.`id` = 1)<br /> User Load (0.000150) SELECT * FROM `user` WHERE (`user`.`id` = 1) <br /><br /><br /><br />User.cache do<br /> User.find(1)<br /> User.find(1)<br /> User.find(1)<br />end<br /> User Load (0.000542) SELECT * FROM `user` WHERE (`user`.`id` = 1)<br /> CACHE (0.000000) SELECT * FROM `user` WHERE (`user`.`id` = 1) <br /> CACHE (0.000000) SELECT * FROM `user` WHERE (`user`.`id` = 1)<br /><br />

CSRF (Cross-Site Request Forgery) & InvalidAuthenticityToken & protect_from_forgery

protect_from_forger api

http://www.g0574.com/thread-221-1-1.html

CSRF (Cross-Site Request Forgery) & InvalidAuthenticityToken & protect_from_forgery

protect_from_forger api

http://www.g0574.com/thread-221-1-1.html

some tips, add_to_base, save_with_validation, verify

<br />save_with_validation(perform_validation = true) <br /><br />The validation process on save can be skipped by passing false. The regular Base#save method is replaced with this when the validations module is mixed in, which it is by default<br /><br />errors.add_to_base<br />http://groups.google.com/group/rubyonrails-talk/browse_thread/thread/e045ec1dead1ff06<br /><br />The "save" and "valid?" methods call errors.clear<br />before running, which was dumping the errors I had added.<br /><br />Should have thought to put it in the model anyway, it is business<br />logic after all. This works:<br /><br />def validate<br /> if items.empty?<br /> errors.add_to_base("Must select at least one item.")<br /> end<br />end <br /><br /><br />http://api.rubyonrails.org/classes/ActionController/Verification/ClassMethods.html#M000353<br /> verify :params => "post", :session => "post", "flash" => "note",<br /> :only => :update_post,<br /> :add_flash => { "alert" => "Failed to create your message" },<br /> :redirect_to => :category_url<br />

some tips, add_to_base, save_with_validation, verify

<br />save_with_validation(perform_validation = true) <br /><br />The validation process on save can be skipped by passing false. The regular Base#save method is replaced with this when the validations module is mixed in, which it is by default<br /><br />errors.add_to_base<br />http://groups.google.com/group/rubyonrails-talk/browse_thread/thread/e045ec1dead1ff06<br /><br />The "save" and "valid?" methods call errors.clear<br />before running, which was dumping the errors I had added.<br /><br />Should have thought to put it in the model anyway, it is business<br />logic after all. This works:<br /><br />def validate<br /> if items.empty?<br /> errors.add_to_base("Must select at least one item.")<br /> end<br />end <br /><br /><br />http://api.rubyonrails.org/classes/ActionController/Verification/ClassMethods.html#M000353<br /> verify :params => "post", :session => "post", "flash" => "note",<br /> :only => :update_post,<br /> :add_flash => { "alert" => "Failed to create your message" },<br /> :redirect_to => :category_url<br />

Some cgi memo

cgi api

CGI 這個 class 提供了一些好用的 method, 一些 url, html 的 encode ,decode
<br />scape(string)<br />#URL-encode a string.<br /> url_encoded_string = CGI::escape("'Stop!' said Fred")<br /> # => "%27Stop%21%27+said+Fred"<br /><br /><br />escapeElement(string, *elements) <br /><br />指定妳想encode 的tag, Escape only the tags of certain HTML elements in string<br /> print CGI::escapeElement('<BR><A HREF="url"></A>', "A", "IMG")<br /> # "<BR><A HREF="url"></A>"<br /><br /> print CGI::escapeElement('<BR><A HREF="url"></A>', ["A", "IMG"])<br /> # "<BR><A HREF="url"></A>"<br /><br /><br /> escapeHTML(string) <br />Escape special characters in HTML, namely &\"<><br /><br /> CGI::escapeHTML('Usage: foo "bar" <baz>')<br /> # => "Usage: foo "bar" <baz>"<br /><br /><br /> parse(query) <br />Parse an HTTP query string into a hash of key=>value pairs.<br /><br />>> CGI::parse("a=b,5&c=d")<br />=> {"a"=>["b,5"], "c"=>["d"]}<br />

Some cgi memo

cgi api

CGI 這個 class 提供了一些好用的 method, 一些 url, html 的 encode ,decode
<br />scape(string)<br />#URL-encode a string.<br /> url_encoded_string = CGI::escape("'Stop!' said Fred")<br /> # => "%27Stop%21%27+said+Fred"<br /><br /><br />escapeElement(string, *elements) <br /><br />指定妳想encode 的tag, Escape only the tags of certain HTML elements in string<br /> print CGI::escapeElement('<BR><A HREF="url"></A>', "A", "IMG")<br /> # "<BR><A HREF="url"></A>"<br /><br /> print CGI::escapeElement('<BR><A HREF="url"></A>', ["A", "IMG"])<br /> # "<BR><A HREF="url"></A>"<br /><br /><br /> escapeHTML(string) <br />Escape special characters in HTML, namely &\"<><br /><br /> CGI::escapeHTML('Usage: foo "bar" <baz>')<br /> # => "Usage: foo "bar" <baz>"<br /><br /><br /> parse(query) <br />Parse an HTTP query string into a hash of key=>value pairs.<br /><br />>> CGI::parse("a=b,5&c=d")<br />=> {"a"=>["b,5"], "c"=>["d"]}<br />

javascript escape html

在rails, 要利用javscript 生成 html 內容要escape 一下, 這時就是用 escape_javascript
<br /> def prepare_js(html)<br /> html.gsub!(/\r|\n/, "")<br /> html = Iconv.conv('big5//TRANSLIT','utf8',html)<br /> html = escape_javascript(html)<br /> html = "document.write('#{html}');"<br /> end<br />

javascript escape html

在rails, 要利用javscript 生成 html 內容要escape 一下, 這時就是用 escape_javascript
<br /> def prepare_js(html)<br /> html.gsub!(/\r|\n/, "")<br /> html = Iconv.conv('big5//TRANSLIT','utf8',html)<br /> html = escape_javascript(html)<br /> html = "document.write('#{html}');"<br /> end<br />

ruby & javascript url encode

api
<br /> var redirect_url = "http://<%= QUOTE_SUBDOMAIN%>.<%=TOP_LEVEL_DOMAIN%><%= PORT.blank? ? '': ":#{PORT}"%>";<br /> redirect_url += '/show/' + cur_target.target_id;<br /> <br /> var url = $(this).attr('href') + encodeURIComponent(redirect_url);<br /> window.open(url); <br /> return false;<br />
而ruby 相對應的 methhod 就是 escape 啦
<br />CGI::escape("http://iwakela.com")<br />

ruby & javascript url encode

api
<br /> var redirect_url = "http://<%= QUOTE_SUBDOMAIN%>.<%=TOP_LEVEL_DOMAIN%><%= PORT.blank? ? '': ":#{PORT}"%>";<br /> redirect_url += '/show/' + cur_target.target_id;<br /> <br /> var url = $(this).attr('href') + encodeURIComponent(redirect_url);<br /> window.open(url); <br /> return false;<br />
而ruby 相對應的 methhod 就是 escape 啦
<br />CGI::escape("http://iwakela.com")<br />

rails 辨識brower

可以用這樣來辨識brower
<br />@opera = /[oO][pP][eE][rR][aA]/.match(request.env["HTTP_USER_AGENT"]) ? true : false<br />

rails 辨識brower

可以用這樣來辨識brower
<br />@opera = /[oO][pP][eE][rR][aA]/.match(request.env["HTTP_USER_AGENT"]) ? true : false<br />

Some good tips

http://errtheblog.com/posts/42-rails-rubyisms-advent
<br />>> { 'days' => 25, 'spirit' => 'giving', 'wallet' => 'empty' }.symbolize_keys<br />=> {:wallet=>"empty", :spirit=>"giving", :days=>25}<br />>> { 'system' => 'wii', :valid_ages => 5..90 }.stringify_keys<br />=> {"valid_ages"=>5..90, "system"=>"wii"}<br /><br />>> colors = { :foreground => 'red', :background => 'black' } <br />=> {:background=>"black", :foreground=>"red"}<br />>> colors.merge(:background => 'green')<br />=> {:background=>"green", :foreground=>"red"}<br /><br /># doesn't override our set colors but would add in :background<br /># if we didn't already have it:<br />>> colors.reverse_merge(:background => 'green')<br />=> {:background=>"black", :foreground=>"red"}<br /><br />>> name = { :first => 'Chris', :last => 'Wanstrath', :middle => 'Jebediah' }<br />=> {:first=>"Chris", :last=>"Wanstrath", :middle=>"Jebediah"}<br />>> name.diff(:first => 'Chris', :last => 'Wanstrath', :middle => 'Jonesy')<br />=> {:middle=>"Jebediah"}<br />>> name.diff(:first => 'Chris', :last => 'Wanstrath')<br />=> {:middle=>"Jebediah"} <br />
<br />>> Hash.from_xml '<posts><post><id>1</id></post></posts>'<br />=> {"posts"=>{"post"=>{"id"=>"1"}}} <br />>> Hash.from_xml '<posts><post><id>1</id></post><post><id>2</id></post></posts>'<br />=> {"posts"=>{"post"=>[{"id"=>"1"}, {"id"=>"2"}]}}<br />
<br /><br />>> 2.even?<br />=> true<br />>> 2.odd?<br />=> false<br />>> 99.multiple_of? 60<br />=> false<br />>> 25.multiple_of? 5<br />=> true<br />
<br /> magical_people = [ { :name => "Santa Claus", :color => "Red" }, <br /> { :name => "Mrs Claus", :color => "Red" }, <br /> { :name => "Twinkle the Elf", :color => "Green "} ]<br />=> [{:name=>"Santa Claus", :color=>"Red"}, {:name=>"Mrs Claus", :color=>"Red"}, {:name=>"Twinkle the Elf", :color=>"green "}]<br />>> magical_people.group_by { |person| person[:color] }<br />=> {"Green "=>[{:name=>"Twinkle the Elf", :color=>"green "}],<br /> "Red"=>[{:name=>"Santa Claus", :color=>"Red"}, {:name=>"Mrs Claus", :color=>"Red"}]} <br />
<br />>> beatles = [{ :first => 'John', :last => 'Lennon' }, <br /> { :first => 'Paul', :last => 'McCartney' }, <br /> { :first => 'Evan', :last => 'Weaver' }, <br /> { :first => 'Ringo', :last => 'Starr' }]<br />=> [{:first=>"John", :last=>"Lennon"}, {:first=>"Paul", :last=>"McCartney"}, {:first=>"Evan", :last=>"Weaver"}, {:first=>"Ringo", :last=>"Starr"}]<br />>> beatles.index_by { |beatle| beatle[:first] }<br />=> {"Evan"=>{:first=>"Evan", :last=>"Weaver"}, <br /> "Paul"=>{:first=>"Paul", :last=>"McCartney"}, <br /> "John"=>{:first=>"John", :last=>"Lennon"}, <br /> "Ringo"=>{:first=>"Ringo", :last=>"Starr"}}<br />
<br />>> [1,2,3,4,5].sum<br />=> 15<br />>> Recipe.find(:all).sum { |recipe| recipe.total_time.to_i }<br />=> 1777<br />
<br />class User < ActiveRecord::Base<br /> alias_attribute :user_id, :id<br />end<br /><br />>> user = User.find(:first)<br />=> #<User:0x12622fc ... ><br />>> user.id<br />=> 1<br />>> user.user_id<br />=> 1<br />>> user.user_id?<br />=> true<br />
<br />>> (7.days.ago..1.day.ago).to_s(:db)<br />=> "BETWEEN '2006-12-11 02:06:50' AND '2006-12-17 02:06:50'" <br />

Some good tips

http://errtheblog.com/posts/42-rails-rubyisms-advent
<br />>> { 'days' => 25, 'spirit' => 'giving', 'wallet' => 'empty' }.symbolize_keys<br />=> {:wallet=>"empty", :spirit=>"giving", :days=>25}<br />>> { 'system' => 'wii', :valid_ages => 5..90 }.stringify_keys<br />=> {"valid_ages"=>5..90, "system"=>"wii"}<br /><br />>> colors = { :foreground => 'red', :background => 'black' } <br />=> {:background=>"black", :foreground=>"red"}<br />>> colors.merge(:background => 'green')<br />=> {:background=>"green", :foreground=>"red"}<br /><br /># doesn't override our set colors but would add in :background<br /># if we didn't already have it:<br />>> colors.reverse_merge(:background => 'green')<br />=> {:background=>"black", :foreground=>"red"}<br /><br />>> name = { :first => 'Chris', :last => 'Wanstrath', :middle => 'Jebediah' }<br />=> {:first=>"Chris", :last=>"Wanstrath", :middle=>"Jebediah"}<br />>> name.diff(:first => 'Chris', :last => 'Wanstrath', :middle => 'Jonesy')<br />=> {:middle=>"Jebediah"}<br />>> name.diff(:first => 'Chris', :last => 'Wanstrath')<br />=> {:middle=>"Jebediah"} <br />
<br />>> Hash.from_xml '<posts><post><id>1</id></post></posts>'<br />=> {"posts"=>{"post"=>{"id"=>"1"}}} <br />>> Hash.from_xml '<posts><post><id>1</id></post><post><id>2</id></post></posts>'<br />=> {"posts"=>{"post"=>[{"id"=>"1"}, {"id"=>"2"}]}}<br />
<br /><br />>> 2.even?<br />=> true<br />>> 2.odd?<br />=> false<br />>> 99.multiple_of? 60<br />=> false<br />>> 25.multiple_of? 5<br />=> true<br />
<br /> magical_people = [ { :name => "Santa Claus", :color => "Red" }, <br /> { :name => "Mrs Claus", :color => "Red" }, <br /> { :name => "Twinkle the Elf", :color => "Green "} ]<br />=> [{:name=>"Santa Claus", :color=>"Red"}, {:name=>"Mrs Claus", :color=>"Red"}, {:name=>"Twinkle the Elf", :color=>"green "}]<br />>> magical_people.group_by { |person| person[:color] }<br />=> {"Green "=>[{:name=>"Twinkle the Elf", :color=>"green "}],<br /> "Red"=>[{:name=>"Santa Claus", :color=>"Red"}, {:name=>"Mrs Claus", :color=>"Red"}]} <br />
<br />>> beatles = [{ :first => 'John', :last => 'Lennon' }, <br /> { :first => 'Paul', :last => 'McCartney' }, <br /> { :first => 'Evan', :last => 'Weaver' }, <br /> { :first => 'Ringo', :last => 'Starr' }]<br />=> [{:first=>"John", :last=>"Lennon"}, {:first=>"Paul", :last=>"McCartney"}, {:first=>"Evan", :last=>"Weaver"}, {:first=>"Ringo", :last=>"Starr"}]<br />>> beatles.index_by { |beatle| beatle[:first] }<br />=> {"Evan"=>{:first=>"Evan", :last=>"Weaver"}, <br /> "Paul"=>{:first=>"Paul", :last=>"McCartney"}, <br /> "John"=>{:first=>"John", :last=>"Lennon"}, <br /> "Ringo"=>{:first=>"Ringo", :last=>"Starr"}}<br />
<br />>> [1,2,3,4,5].sum<br />=> 15<br />>> Recipe.find(:all).sum { |recipe| recipe.total_time.to_i }<br />=> 1777<br />
<br />class User < ActiveRecord::Base<br /> alias_attribute :user_id, :id<br />end<br /><br />>> user = User.find(:first)<br />=> #<User:0x12622fc ... ><br />>> user.id<br />=> 1<br />>> user.user_id<br />=> 1<br />>> user.user_id?<br />=> true<br />
<br />>> (7.days.ago..1.day.ago).to_s(:db)<br />=> "BETWEEN '2006-12-11 02:06:50' AND '2006-12-17 02:06:50'" <br />

字串 String 一些好用的 function, scan, split, match, gsub, sub, grep

Scan
<br />=begin<br /> a = "cruel world"<br /> a.scan(/\w+/) #=> ["cruel", "world"]<br /> a.scan(/.../) #=> ["cru", "el ", "wor"]<br /> a.scan(/(...)/) #=> [["cru"], ["el "], ["wor"]]<br /> a.scan(/(..)(..)/) #=> [["cr", "ue"], ["l ", "wo"]]<br /><br /> $` before match string<br /> $' after match string<br /> $& entire match string<br />=end<br /><br /><br /><br />>> "111111222222333".scan(/....../).push($')<br />=> ["111111", "222222", "333"]<br />
<br /> def wbr_by_6(long_word)<br /> if long_word.chars.size > 6<br /> long_word.scan(/....../).push($').map{|m| CGI.escapeHTML(m)}.join('<wbr>')<br /> else<br /> CGI.escapeHTML(long_word)<br /> end <br /> end <br /> <br /> def format_content(content)<br /> <br /> def sub_url(text) <br /> if text =~ URI.regexp && $&[0,4] == 'http'<br /> "#{$`}<a href='#{$&}'>#{wbr_by_6($&)}</a>#{sub_url($')}"<br /> else<br /> #content = CGI.escapeHTML(content)<br /> wbr_by_6(text)<br /> end<br /> end<br /><br /> sub_url(content)<br /> end<br />
Split
<br />" now's the time".split #=> ["now's", "the", "time"]<br /> " now's the time".split(' ') #=> ["now's", "the", "time"]<br /> " now's the time".split(/ /) #=> ["", "now's", "", "the", "time"]<br /> "1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"]<br /> "hello".split(//) #=> ["h", "e", "l", "l", "o"]<br /> "hello".split(//, 3) #=> ["h", "e", "llo"]<br /> "hi mom".split(%r{\s*}) #=> ["h", "i", "m", "o", "m"]<br /><br /> "mellow yellow".split("ello") #=> ["m", "w y", "w"]<br /> "1,2,,3,4,,".split(',') #=> ["1", "2", "", "3", "4"]<br /> "1,2,,3,4,,".split(',', 4) #=> ["1", "2", "", "3,4,,"]<br /> "1,2,,3,4,,".split(',', -4) #=> ["1", "2", "", "3", "4", "", ""]<br /><br />>> %w[Tom Jerry and Mickey and Pluto].split('and')<br />=> [["Tom", "Jerry"], ["Mickey"], ["Pluto"]] <br />>> %w[Chris Mark Adam Tommy Martin Oliver].split { |name| name.first == 'M' }<br />=> [["Chris"], ["Adam", "Tommy"], ["Oliver"]]<br /><br />
Match and Scan 感受一下啥時要用啥吧
<br />MESSAGE_REGEX = /^([@#&?$\/>])\s*([^\s]+)\s*(\w*)/<br /><br />>> MESSAGE_REGEX.match("@lake lalaa ").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br /><br />array 傳回的第一個是整個match 的部份, 後面是()的部份<br /><br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a.push($')<br />=> ["@lake lalaa", "@", "lake", "lalaa", " 123"]<br /><br />跟scan 很像吧, 玩玩有啥不同<br /><br />>> "@lake lalaa 123".scan(MESSAGE_REGEX)<br />=> [["@", "lake", "lalaa"]]<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> [["@", "lake", "lalaa"], " 123"]<br /><br />外面又包了一層 Array<br /><br />把regexp 的()拿掉<br />>> MESSAGE_REGEX = /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />(irb):57: warning: already initialized constant MESSAGE_REGEX<br />=> /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> ["@lake lalaa", " 123"]<br /><br />
gsub and sub 就是 replace 只是一個全部, 一個只有第一個
<br /> "hello".gsub(/[aeiou]/, '*') #=> "h*ll*"<br /> "hello".gsub(/([aeiou])/, '<\1>') #=> "h<e>ll<o>"<br /> "hello".gsub(/./) {|s| s[0].to_s + ' '} #=> "104 101 108 108 111 "<br />

<br />至少要是string, 3 連string 都不是<br />>> ["1","2",3].grep(/\d/)<br />=> ["1", "2"]<br />

字串 String 一些好用的 function, scan, split, match, gsub, sub, grep

Scan
<br />=begin<br /> a = "cruel world"<br /> a.scan(/\w+/) #=> ["cruel", "world"]<br /> a.scan(/.../) #=> ["cru", "el ", "wor"]<br /> a.scan(/(...)/) #=> [["cru"], ["el "], ["wor"]]<br /> a.scan(/(..)(..)/) #=> [["cr", "ue"], ["l ", "wo"]]<br /><br /> $` before match string<br /> $' after match string<br /> $& entire match string<br />=end<br /><br /><br /><br />>> "111111222222333".scan(/....../).push($')<br />=> ["111111", "222222", "333"]<br />
<br /> def wbr_by_6(long_word)<br /> if long_word.chars.size > 6<br /> long_word.scan(/....../).push($').map{|m| CGI.escapeHTML(m)}.join('<wbr>')<br /> else<br /> CGI.escapeHTML(long_word)<br /> end <br /> end <br /> <br /> def format_content(content)<br /> <br /> def sub_url(text) <br /> if text =~ URI.regexp && $&[0,4] == 'http'<br /> "#{$`}<a href='#{$&}'>#{wbr_by_6($&)}</a>#{sub_url($')}"<br /> else<br /> #content = CGI.escapeHTML(content)<br /> wbr_by_6(text)<br /> end<br /> end<br /><br /> sub_url(content)<br /> end<br />
Split
<br />" now's the time".split #=> ["now's", "the", "time"]<br /> " now's the time".split(' ') #=> ["now's", "the", "time"]<br /> " now's the time".split(/ /) #=> ["", "now's", "", "the", "time"]<br /> "1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"]<br /> "hello".split(//) #=> ["h", "e", "l", "l", "o"]<br /> "hello".split(//, 3) #=> ["h", "e", "llo"]<br /> "hi mom".split(%r{\s*}) #=> ["h", "i", "m", "o", "m"]<br /><br /> "mellow yellow".split("ello") #=> ["m", "w y", "w"]<br /> "1,2,,3,4,,".split(',') #=> ["1", "2", "", "3", "4"]<br /> "1,2,,3,4,,".split(',', 4) #=> ["1", "2", "", "3,4,,"]<br /> "1,2,,3,4,,".split(',', -4) #=> ["1", "2", "", "3", "4", "", ""]<br /><br />>> %w[Tom Jerry and Mickey and Pluto].split('and')<br />=> [["Tom", "Jerry"], ["Mickey"], ["Pluto"]] <br />>> %w[Chris Mark Adam Tommy Martin Oliver].split { |name| name.first == 'M' }<br />=> [["Chris"], ["Adam", "Tommy"], ["Oliver"]]<br /><br />
Match and Scan 感受一下啥時要用啥吧
<br />MESSAGE_REGEX = /^([@#&?$\/>])\s*([^\s]+)\s*(\w*)/<br /><br />>> MESSAGE_REGEX.match("@lake lalaa ").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br /><br />array 傳回的第一個是整個match 的部份, 後面是()的部份<br /><br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a.push($')<br />=> ["@lake lalaa", "@", "lake", "lalaa", " 123"]<br /><br />跟scan 很像吧, 玩玩有啥不同<br /><br />>> "@lake lalaa 123".scan(MESSAGE_REGEX)<br />=> [["@", "lake", "lalaa"]]<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> [["@", "lake", "lalaa"], " 123"]<br /><br />外面又包了一層 Array<br /><br />把regexp 的()拿掉<br />>> MESSAGE_REGEX = /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />(irb):57: warning: already initialized constant MESSAGE_REGEX<br />=> /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> ["@lake lalaa", " 123"]<br /><br />
gsub and sub 就是 replace 只是一個全部, 一個只有第一個
<br /> "hello".gsub(/[aeiou]/, '*') #=> "h*ll*"<br /> "hello".gsub(/([aeiou])/, '<\1>') #=> "h<e>ll<o>"<br /> "hello".gsub(/./) {|s| s[0].to_s + ' '} #=> "104 101 108 108 111 "<br />

<br />至少要是string, 3 連string 都不是<br />>> ["1","2",3].grep(/\d/)<br />=> ["1", "2"]<br />

字串 String 一些好用的 function, scan, split, match, gsub, sub

Scan
<br />=begin<br /> a = "cruel world"<br /> a.scan(/\w+/) #=> ["cruel", "world"]<br /> a.scan(/.../) #=> ["cru", "el ", "wor"]<br /> a.scan(/(...)/) #=> [["cru"], ["el "], ["wor"]]<br /> a.scan(/(..)(..)/) #=> [["cr", "ue"], ["l ", "wo"]]<br /><br /> $` before match string<br /> $' after match string<br /> $& entire match string<br />=end<br /><br /><br /><br />>> "111111222222333".scan(/....../).push($')<br />=> ["111111", "222222", "333"]<br />
<br /> def wbr_by_6(long_word)<br /> if long_word.chars.size > 6<br /> long_word.scan(/....../).push($').map{|m| CGI.escapeHTML(m)}.join('<wbr>')<br /> else<br /> CGI.escapeHTML(long_word)<br /> end <br /> end <br /> <br /> def format_content(content)<br /> <br /> def sub_url(text) <br /> if text =~ URI.regexp && $&[0,4] == 'http'<br /> "#{$`}<a href='#{$&}'>#{wbr_by_6($&)}</a>#{sub_url($')}"<br /> else<br /> #content = CGI.escapeHTML(content)<br /> wbr_by_6(text)<br /> end<br /> end<br /><br /> sub_url(content)<br /> end<br />
Split
<br />" now's the time".split #=> ["now's", "the", "time"]<br /> " now's the time".split(' ') #=> ["now's", "the", "time"]<br /> " now's the time".split(/ /) #=> ["", "now's", "", "the", "time"]<br /> "1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"]<br /> "hello".split(//) #=> ["h", "e", "l", "l", "o"]<br /> "hello".split(//, 3) #=> ["h", "e", "llo"]<br /> "hi mom".split(%r{\s*}) #=> ["h", "i", "m", "o", "m"]<br /><br /> "mellow yellow".split("ello") #=> ["m", "w y", "w"]<br /> "1,2,,3,4,,".split(',') #=> ["1", "2", "", "3", "4"]<br /> "1,2,,3,4,,".split(',', 4) #=> ["1", "2", "", "3,4,,"]<br /> "1,2,,3,4,,".split(',', -4) #=> ["1", "2", "", "3", "4", "", ""]<br />
Match and Scan 感受一下啥時要用啥吧
<br />MESSAGE_REGEX = /^([@#&?$\/>])\s*([^\s]+)\s*(\w*)/<br /><br />>> MESSAGE_REGEX.match("@lake lalaa ").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br /><br />array 傳回的第一個是整個match 的部份, 後面是()的部份<br /><br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a.push($')<br />=> ["@lake lalaa", "@", "lake", "lalaa", " 123"]<br /><br />跟scan 很像吧, 玩玩有啥不同<br /><br />>> "@lake lalaa 123".scan(MESSAGE_REGEX)<br />=> [["@", "lake", "lalaa"]]<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> [["@", "lake", "lalaa"], " 123"]<br /><br />外面又包了一層 Array<br /><br />把regexp 的()拿掉<br />>> MESSAGE_REGEX = /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />(irb):57: warning: already initialized constant MESSAGE_REGEX<br />=> /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> ["@lake lalaa", " 123"]<br /><br />
gsub and sub 就是 replace 只是一個全部, 一個只有第一個
<br /> "hello".gsub(/[aeiou]/, '*') #=> "h*ll*"<br /> "hello".gsub(/([aeiou])/, '<\1>') #=> "h<e>ll<o>"<br /> "hello".gsub(/./) {|s| s[0].to_s + ' '} #=> "104 101 108 108 111 "<br />

字串 String 一些好用的 function, scan, split, match, gsub, sub

Scan
<br />=begin<br /> a = "cruel world"<br /> a.scan(/\w+/) #=> ["cruel", "world"]<br /> a.scan(/.../) #=> ["cru", "el ", "wor"]<br /> a.scan(/(...)/) #=> [["cru"], ["el "], ["wor"]]<br /> a.scan(/(..)(..)/) #=> [["cr", "ue"], ["l ", "wo"]]<br /><br /> $` before match string<br /> $' after match string<br /> $& entire match string<br />=end<br /><br /><br /><br />>> "111111222222333".scan(/....../).push($')<br />=> ["111111", "222222", "333"]<br />
<br /> def wbr_by_6(long_word)<br /> if long_word.chars.size > 6<br /> long_word.scan(/....../).push($').map{|m| CGI.escapeHTML(m)}.join('<wbr>')<br /> else<br /> CGI.escapeHTML(long_word)<br /> end <br /> end <br /> <br /> def format_content(content)<br /> <br /> def sub_url(text) <br /> if text =~ URI.regexp && $&[0,4] == 'http'<br /> "#{$`}<a href='#{$&}'>#{wbr_by_6($&)}</a>#{sub_url($')}"<br /> else<br /> #content = CGI.escapeHTML(content)<br /> wbr_by_6(text)<br /> end<br /> end<br /><br /> sub_url(content)<br /> end<br />
Split
<br />" now's the time".split #=> ["now's", "the", "time"]<br /> " now's the time".split(' ') #=> ["now's", "the", "time"]<br /> " now's the time".split(/ /) #=> ["", "now's", "", "the", "time"]<br /> "1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"]<br /> "hello".split(//) #=> ["h", "e", "l", "l", "o"]<br /> "hello".split(//, 3) #=> ["h", "e", "llo"]<br /> "hi mom".split(%r{\s*}) #=> ["h", "i", "m", "o", "m"]<br /><br /> "mellow yellow".split("ello") #=> ["m", "w y", "w"]<br /> "1,2,,3,4,,".split(',') #=> ["1", "2", "", "3", "4"]<br /> "1,2,,3,4,,".split(',', 4) #=> ["1", "2", "", "3,4,,"]<br /> "1,2,,3,4,,".split(',', -4) #=> ["1", "2", "", "3", "4", "", ""]<br />
Match and Scan 感受一下啥時要用啥吧
<br />MESSAGE_REGEX = /^([@#&?$\/>])\s*([^\s]+)\s*(\w*)/<br /><br />>> MESSAGE_REGEX.match("@lake lalaa ").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a<br />=> ["@lake lalaa", "@", "lake", "lalaa"]<br /><br />array 傳回的第一個是整個match 的部份, 後面是()的部份<br /><br />>> MESSAGE_REGEX.match("@lake lalaa 123").to_a.push($')<br />=> ["@lake lalaa", "@", "lake", "lalaa", " 123"]<br /><br />跟scan 很像吧, 玩玩有啥不同<br /><br />>> "@lake lalaa 123".scan(MESSAGE_REGEX)<br />=> [["@", "lake", "lalaa"]]<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> [["@", "lake", "lalaa"], " 123"]<br /><br />外面又包了一層 Array<br /><br />把regexp 的()拿掉<br />>> MESSAGE_REGEX = /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />(irb):57: warning: already initialized constant MESSAGE_REGEX<br />=> /^[@#&?$\/>]\s*[^\s]+\s*\w*/<br />>> "@lake lalaa 123".scan(MESSAGE_REGEX).push($')<br />=> ["@lake lalaa", " 123"]<br /><br />
gsub and sub 就是 replace 只是一個全部, 一個只有第一個
<br /> "hello".gsub(/[aeiou]/, '*') #=> "h*ll*"<br /> "hello".gsub(/([aeiou])/, '<\1>') #=> "h<e>ll<o>"<br /> "hello".gsub(/./) {|s| s[0].to_s + ' '} #=> "104 101 108 108 111 "<br />

CSS Tools: Reset CSS

CSS Tools: Reset CSS

The goal of a reset stylesheet is to reduce browser inconsistencies in things like default line heights, margins and font sizes of headings, and so on.

為了減少個瀏覽器間一些 default tag 的差異, 所以有了這些css, 像Blueprint就是css的 framework 讓你省去css development 時間

CSS Tools: Reset CSS

CSS Tools: Reset CSS

The goal of a reset stylesheet is to reduce browser inconsistencies in things like default line heights, margins and font sizes of headings, and so on.

為了減少個瀏覽器間一些 default tag 的差異, 所以有了這些css, 像Blueprint就是css的 framework 讓你省去css development 時間

Top 10 Ruby on Rails performance tips

Top 10 Ruby on Rails performance tips

1. 最佳化你的ruby code
1.1 如果內建就有, 就別自己幹
1.2 能用regular expression 就別用loop
1.3 用 Libxml 別用 REXML 如果妳要parse xml
1.4 define_method, yield 動態生function 很方便, 可是也要好好評量一下
1.5 儘量別用loop,
1.6 if/unless 可以儘量簡單或別用, 別忘了 ||=
1.7 Hash 很貴, 如果妳有需要常用的話, 把他存在local variable裡


2. Cache is good
2.1 model : cached_model gem
2.2 page : extended_fragment_cache

3. finders are great but be careful
3.1 select , 只拿妳需要的
3.2 別忘了 include
3.3 MyModel.find_by_* 會痛 別用
3.4 想快 就用 find_by_sql

4. Group operations in a transaction:
!! 用transaction 包起來這樣比較快, 如果妳有需要不停的insert or update record 的話
<br />Insead of:<br /><br /> my_collection.each do |q|<br /> Quote.create({:phrase => q})<br /> end<br /><br />Use:<br /><br />Quote.transaction do<br /> my_collection.each do |q|<br /> Quote.create({:phrase => q})<br /> end<br />end<br /><br />or for rolling back the whole transaction if any insert fails, use:<br /><br />Quote.transaction do<br /> my_collection.each do |q|<br /> quote = Quote.new({:phrase => q})<br /> quote.save!<br /> end<br />end<br />

5. Control your controllers
5.1 filter 很貴, 別用太多, instance variable 也是

6. Use HTML for your views:
6.1 helper 別用太爽

7. Logging
7.1 logging 也很貴, 別啥都記

8. Profile 是好物

Top 10 Ruby on Rails performance tips

Top 10 Ruby on Rails performance tips

1. 最佳化你的ruby code
1.1 如果內建就有, 就別自己幹
1.2 能用regular expression 就別用loop
1.3 用 Libxml 別用 REXML 如果妳要parse xml
1.4 define_method, yield 動態生function 很方便, 可是也要好好評量一下
1.5 儘量別用loop,
1.6 if/unless 可以儘量簡單或別用, 別忘了 ||=
1.7 Hash 很貴, 如果妳有需要常用的話, 把他存在local variable裡


2. Cache is good
2.1 model : cached_model gem
2.2 page : extended_fragment_cache

3. finders are great but be careful
3.1 select , 只拿妳需要的
3.2 別忘了 include
3.3 MyModel.find_by_* 會痛 別用
3.4 想快 就用 find_by_sql

4. Group operations in a transaction:
!! 用transaction 包起來這樣比較快, 如果妳有需要不停的insert or update record 的話
<br />Insead of:<br /><br /> my_collection.each do |q|<br /> Quote.create({:phrase => q})<br /> end<br /><br />Use:<br /><br />Quote.transaction do<br /> my_collection.each do |q|<br /> Quote.create({:phrase => q})<br /> end<br />end<br /><br />or for rolling back the whole transaction if any insert fails, use:<br /><br />Quote.transaction do<br /> my_collection.each do |q|<br /> quote = Quote.new({:phrase => q})<br /> quote.save!<br /> end<br />end<br />

5. Control your controllers
5.1 filter 很貴, 別用太多, instance variable 也是

6. Use HTML for your views:
6.1 helper 別用太爽

7. Logging
7.1 logging 也很貴, 別啥都記

8. Profile 是好物

[HTML] IE 表單 Enter 的 Bug

[HTML] IE 表單 Enter 的 Bug

ie 只有一個input box 不給submit 那就在補它一個hide 起來的input box

[HTML] IE 表單 Enter 的 Bug

[HTML] IE 表單 Enter 的 Bug

ie 只有一個input box 不給submit 那就在補它一個hide 起來的input box