Proper syntax for text_field

rubyonrails-talk
1

Sorry for this basic noob question:

I have an "Item" class in my models which corresponds to a SQL table, and a "Cart" class and a "CartItem" class which do not. The Item class does not have an amount object, which is transitory, so I've put this amount object in my CartItem class:

class CartItem

  attr_reader :item, :amount

  def initialize( item )     @item = item   end

  def set_amount( amount )    This.amount = amount   end

end

I have a list of items in a viewer form, and I'd like to pass associated amount to my CartItem when the user hits the "Add to Cart" button. I've tried many variations of text_field and text_field_tag in:

  <% @items.each do |item| %> ...     <%= text_field( :amount , :action => 'set_amount( :amount )', :id => item )%>     <%= button_to "Add to Cart" , :action => 'add_to_cart', :id => item %> ...   <% end %>

I know the text_field up there is severely mangled and won't work--but it's an example of the 2000th try, the last several hundred out of pure desperation. Can anyone help with the proper syntax for the text_field in the .html.emb file?

The add_to_cart call with the button is working:

def add_to_cart     item = Item.find( params[ :id ] )     @cart = find_cart     @cart.add_item( item ) end

Many TIA, Craig

2

Text fields don't take actions, they're just text fields with some optional aesthetics. put :amount in there, and if item.amount exists, it will be filled in.

http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#M001607

Also, ruby doesn't use This, it's "self."

There may be other problems in find_cart and add_item.

3

Sorry for this basic noob question:

I have an “Item” class in my models which corresponds to a SQL table,

and a “Cart” class and a “CartItem” class which do not. The Item

class does not have an amount object, which is transitory, so I’ve put

this amount object in my CartItem class:

class CartItem

attr_reader :item, :amount

def initialize( item )

@item = item

end

def set_amount( amount )

This.amount = amount

end

end

I have a list of items in a viewer form, and I’d like to pass

associated amount to my CartItem when the user hits the “Add to Cart”

button. I’ve tried many variations of text_field and text_field_tag

in:

    <% @items.each do |item| %>

…

            <%= text_field( :amount , :action => 'set_amount( :amount )', :id =>

item )%>

            <%= button_to "Add to Cart" , :action => 'add_to_cart', :id => item

%>

…

    <% end %>

I know the text_field up there is severely mangled and won’t work–but

it’s an example of the 2000th try, the last several hundred out of

pure desperation. Can anyone help with the proper syntax for the

text_field in the .html.emb file?

The add_to_cart call with the button is working:

def add_to_cart

item = Item.find( params[ :id ] )

@cart = find_cart

@cart.add_item( item )

end

Many TIA,

Craig

The text_field view helper generates an HTML input tag. Thus, there’s no attribute on the input tag called ‘action’ in the X/HTML spec.

Next, when to use text_field and text_field_tag?

text_field: if you’re creating or updating a model.

text_field_tag: if you’re NOT creating or updating a model.

Thus, I’m guessing that you’re simply updating a session variable when you’re performing the

@cart.add_item( item )

If this is the case, then you should use text_field_tag within a form_tag. You can see

example usage of ‘form_tag’ and ‘text_field_tag’ here:

http://api.rubyonrails.org/classes/ActionView/Helpers/FormTagHelper.html#M001729

If you are in fact creating or updating a model, then you should use test_field within a form_for.

You can see examples usage of ‘form_for’ and ‘text_field’ here:

http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#M001607

Finally, I would recommend getting access to a copy of “Agile Web Development with Rails 3rd ed”

and/or obtaining the really great screencasts on the subject, “Mastering Rails Form”,

http://www.pragprog.com/screencasts/v-rbforms/mastering-rails-forms

Good luck,

-Conrad

4

Thanks, Eric. What I'm struggling with is how to set a variable, rather than get one. What would be the proper form for setting SomeObject.amount?

Thanks for the correction on "This". Old habits die hard :slight_smile:

5

Thanks, Eric. What I’m struggling with is how to set a variable,

rather than get one. What would be the proper form for setting

SomeObject.amount?

Thanks for the correction on “This”. Old habits die hard :slight_smile:

Text fields don’t take actions, they’re just text fields with some

optional aesthetics. put :amount in there, and if item.amount exists,

it will be filled in.

http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html.…

Also, ruby doesn’t use This, it’s “self.”

There may be other problems in find_cart and add_item.

Sorry for this basic noob question:

I have an “Item” class in my models which corresponds to a SQL table,

and a “Cart” class and a “CartItem” class which do not. The Item

class does not have an amount object, which is transitory, so I’ve put

this amount object in my CartItem class:

class CartItem

attr_reader :item, :amount

def initialize( item )

@item = item

end

def set_amount( amount )

This.amount = amount

end

end

I have a list of items in a viewer form, and I’d like to pass

associated amount to my CartItem when the user hits the “Add to Cart”

button. I’ve tried many variations of text_field and text_field_tag

in:

    <% @items.each do |item| %>

…

            <%= text_field( :amount , :action => 'set_amount( :amount )', :id =>

item )%>

            <%= button_to "Add to Cart" , :action => 'add_to_cart', :id => item

%>

…

    <% end %>

I know the text_field up there is severely mangled and won’t work–but

it’s an example of the 2000th try, the last several hundred out of

pure desperation. Can anyone help with the proper syntax for the

text_field in the .html.emb file?

The add_to_cart call with the button is working:

def add_to_cart

item = Item.find( params[ :id ] )

@cart = find_cart

@cart.add_item( item )

end

Many TIA,

Craig

<%= text_field( :amount, :value => some_value, :id => item ) %>

-Conrad

6

I don't understand the question here. Are you trying to set the content of the text field when it is displayed or set a variable in your controller? If the latter then the value the user enters gets passed to the controller in the params hash.

Colin

7

Thanks, Conrad. I did the "depot" tutorial in the Agile Rails book 3rd ed, and the whole pod/screencast on learningrails.com. Both are light on forms. I just downloaded the 3 Mastering Rails Form screencasts, and am going through the first--it's *excellent*. Just knowing about debug params is worth its weight in gold :slight_smile: I'll go through the first one, try my code again, then if I'm still having trouble, repost. Thanks, Colin & Eric for your patience with this noob :slight_smile: