diff options
Diffstat (limited to 'railties/guides/source/form_helpers.textile')
-rw-r--r-- | railties/guides/source/form_helpers.textile | 48 |
1 files changed, 26 insertions, 22 deletions
diff --git a/railties/guides/source/form_helpers.textile b/railties/guides/source/form_helpers.textile index ce0f66b2c1..e178a60307 100644 --- a/railties/guides/source/form_helpers.textile +++ b/railties/guides/source/form_helpers.textile @@ -59,15 +59,15 @@ To create this form you will use +form_tag+, +label_tag+, +text_field_tag+, and A basic search form -<html> +<erb> <%= form_tag(search_path, :method => "get") do %> <%= label_tag(:q, "Search for:") %> <%= text_field_tag(:q) %> <%= submit_tag("Search") %> <% end %> -</html> +</erb> -TIP: +search_path+ can be a named route specified in "routes.rb": <br /><tt>map.search "search", :controller => "search"</tt> +TIP: +search_path+ can be a named route specified in "routes.rb" as: <br /><code>match "search" => "search"</code> This declares that path "/search" will be handled by action "search" belonging to controller "search". The above view code will result in the following markup: @@ -107,7 +107,7 @@ WARNING: Do not delimit the second hash without doing so with the first hash, ot h4. Helpers for Generating Form Elements -Rails provides a series of helpers for generating form elements such as checkboxes, text fields, radio buttons, and so on. These basic helpers, with names ending in <notextile>_tag</notextile> such as +text_field_tag+, +check_box_tag+, etc., generate just a single +<input>+ element. The first parameter to these is always the name of the input. In the controller this name will be the key in the +params+ hash used to get the value entered by the user. For example, if the form contains +Rails provides a series of helpers for generating form elements such as checkboxes, text fields and radio buttons. These basic helpers, with names ending in <notextile>_tag</notextile> such as +text_field_tag+ and +check_box_tag+ generate just a single +<input>+ element. The first parameter to these is always the name of the input. In the controller this name will be the key in the +params+ hash used to get the value entered by the user. For example, if the form contains <erb> <%= text_field_tag(:query) %> @@ -127,17 +127,19 @@ Checkboxes are form controls that give the user a set of options they can enable <erb> <%= check_box_tag(:pet_dog) %> - <%= label_tag(:pet_dog, "I own a dog") %> +<%= label_tag(:pet_dog, "I own a dog") %> <%= check_box_tag(:pet_cat) %> - <%= label_tag(:pet_cat, "I own a cat") %> +<%= label_tag(:pet_cat, "I own a cat") %> +</erb> output: +<html> <input id="pet_dog" name="pet_dog" type="checkbox" value="1" /> - <label for="pet_dog">I own a dog</label> +<label for="pet_dog">I own a dog</label> <input id="pet_cat" name="pet_cat" type="checkbox" value="1" /> - <label for="pet_cat">I own a cat</label> -</erb> +<label for="pet_cat">I own a cat</label> +</html> The second parameter to +check_box_tag+ is the value of the input. This is the value that will be submitted by the browser if the checkbox is ticked (i.e. the value that will be present in the +params+ hash). With the above form you would check the value of +params[:pet_dog]+ and +params[:pet_cat]+ to see which pets the user owns. @@ -147,17 +149,19 @@ Radio buttons, while similar to checkboxes, are controls that specify a set of o <erb> <%= radio_button_tag(:age, "child") %> - <%= label_tag(:age_child, "I am younger than 21") %> +<%= label_tag(:age_child, "I am younger than 21") %> <%= radio_button_tag(:age, "adult") %> - <%= label_tag(:age_adult, "I'm over 21") %> +<%= label_tag(:age_adult, "I'm over 21") %> +</erb> output: +<html> <input id="age_child" name="age" type="radio" value="child" /> - <label for="age_child">I am younger than 21</label> +<label for="age_child">I am younger than 21</label> <input id="age_adult" name="age" type="radio" value="adult" /> - <label for="age_adult">I'm over 21</label> -</erb> +<label for="age_adult">I'm over 21</label> +</html> As with +check_box_tag+ the second parameter to +radio_button_tag+ is the value of the input. Because these two radio buttons share the same name (age) the user will only be able to select one and +params[:age]+ will contain either "child" or "adult". @@ -171,13 +175,15 @@ Other form controls worth mentioning are the text area, password input and hidde <%= text_area_tag(:message, "Hi, nice site", :size => "24x6") %> <%= password_field_tag(:password) %> <%= hidden_field_tag(:parent_id, "5") %> +</erb> output: +<html> <textarea id="message" name="message" cols="24" rows="6">Hi, nice site</textarea> <input id="password" name="password" type="password" /> <input id="parent_id" name="parent_id" type="hidden" value="5" /> -</erb> +</html> Hidden inputs are not shown to the user, but they hold data like any textual input. Values inside them can be changed with JavaScript. @@ -226,13 +232,13 @@ The corresponding view +app/views/articles/new.html.erb+ using +form_for+ looks <%= form_for @article, :url => { :action => "create" }, :html => {:class => "nifty_form"} do |f| %> <%= f.text_field :title %> <%= f.text_area :body, :size => "60x12" %> - <%= submit_tag "Create" %> + <%= f.submit "Create" %> <% end %> </erb> There are a few things to note here: -# +:article+ is the name of the model and +@article+ is the actual object being edited. +# +@article+ is the actual object being edited. # There is a single hash of options. Routing options are passed in the +:url+ hash, HTML options are passed in the +:html+ hash. # The +form_for+ method yields a *form builder* object (the +f+ variable). # Methods to create form controls are called *on* the form builder object +f+ @@ -278,7 +284,7 @@ h4. Relying on Record Identification The Article model is directly available to users of the application, so -- following the best practices for developing with Rails -- you should declare it *a resource*: <ruby> -map.resources :articles +resources :articles </ruby> TIP: Declaring a resource has a number of side-affects. See "Rails Routing From the Outside In":routing.html#resource-routing-the-rails-default for more information on setting up and using resources. @@ -288,13 +294,13 @@ When dealing with RESTful resources, calls to +form_for+ can get significantly e <ruby> ## Creating a new article # long-style: -form_for(:article, @article, :url => articles_path) +form_for(@article, :url => articles_path) # same thing, short-style (record identification gets used): form_for(@article) ## Editing an existing article # long-style: -form_for(:article, @article, :url => article_path(@article), :html => { :method => "put" }) +form_for(@article, :url => article_path(@article), :html => { :method => "put" }) # short-style: form_for(@article) </ruby> @@ -770,8 +776,6 @@ Many apps grow beyond simple forms editing a single object. For example when cre h3. Changelog -"Lighthouse ticket":http://rails.lighthouseapp.com/projects/16213-rails-guides/tickets/1 - * April 6, 2010: Fixed document to validate XHTML 1.0 Strict. "Jaime Iniesta":http://jaimeiniesta.com h3. Authors |