I have written the following code in my Rails app to generate XML. I am using Aptana IDE to do Rails development and the IDE shows a warning that the code structure is identical in both the blocks. What changes can be done to the code to remove the duplicity in structure? Is there any other way to write the same?
xml.roles do
#rolesList.each do |r|
xml.role(:id => r["role_id"], :name => r["role_name"])
end
end
xml.levels do
#levelsList.each do |lvl|
xml.level(:id => lvl["level_id"], :name => lvl["level_name"])
end
end
I had the same issue with using the send method and getting tags that looked like <send:id>12</send:id>. To resolve, I used the "tag!" method. So I think your code would look like:
def build_xml(node_name, node_list)
xml.tag!(node_name.pluralize) do
node_list.each do |node|
id_str = node["#{node_name}_id"]
name_str = node["#{node_name}_name"]
xml.tag!(node_name, :id => id_str, :name => name_str)
end
end
end
I had a similar idea to #nathandva, but using send properly:
def list_to_xml(node_name, list)
xml.send(node_name.pluralize.to_sym) do
list.each do |item|
xml.send(node_name.to_sym, :id => r["#{node_name}_id"],
:name => r["#{node_name}_name"])
end
end
end
Since it adds visual complexity, this change may not be the best. The biggest question is: if you are likely to make a change to xml.roles structure, are you likely to change xml.levels as well? If so, definitely remove the duplication. It is also important to name the method something that will make sense to you upon reading it; add that point the complexity will be reduced not increased.
Something like this?
def build_xml(node_name, node_list)
xml.send(node_name.pluralize) do
node_list.each do |node|
id_str = node["#{node_name}_id"]
name_str = node["#{node_name}_name"]
xml.send(node_name, :id => id_str, :name => name_str)
end
end
end
build_xml("role", #roleslist)
build_xml("level", #levelslist)
I am trying to use send instead of eval [which i did not do to well: edited it to correct it --thanks to Kathy Van Stone].
Edit 26/12 because the xml builder will capture the send and use it as a xml branch there are two possible options, use the send method instead, like this
xml.__send__(node_name, :id => id_str, :name => name_str)
but i am not sure whether it will create a <__send__:roles> instead. You could always fall back to
eval("xml.#{node_name} :id => '#{id_str}', :name => '#{name_str}'")
which should definitely work (but eval should always be used a last resort).
Related
I would like to make editing form fields as user-friendly as possible. For example, for numeric values, I would like the field to be displayed with commas (like number_with_precision).
This is easy enough on the display side, but what about editing? Is there a good way to do this?
I am using the Rails FormBuilder. Upon investigation, I found that it uses InstanceTag, which gets the values for fields by using <attribute>_value_before_type_cast which means overriding <attribute> won't get called.
The best I have come up with so far is something like this:
<%= f.text_field :my_attribute, :value => number_with_precision(f.object.my_attribute) %>
Or my_attribute could return the formatted value, like this:
def my_attribute
ApplicationController.helpers.number_with_precision(read_attribute(:my_attribute))
end
But you still have to use :value
<%= f.text_field :my_attribute, :value => f.object.my_attribute %>
This seems like a lot of work.
I prefer your first answer, with the formatting being done in the view. However, if you want to perform the formatting in the model, you can use wrapper methods for the getter and setter, and avoid having to use the :value option entirely.
You'd end up with something like this.
def my_attribute_string
foo_formatter(myattribute)
end
def my_attribute_string=(s)
# Parse "s" or do whatever you need to with it, then set your real attribute.
end
<%= f.text_field :my_attribute_string %>
Railscasts covered this with a Time object in a text_field in episode #32. The really clever part of this is how they handle validation errors. It's worth watching the episode for that alone.
This is an old question, but in case anyone comes across this you could use the number_to_X helpers. They have all of the attributes you could ever want for displaying your edit value:
<%= f.text_field :my_number, :value => number_to_human(f.object.my_number, :separator => '', :unit => '', :delimiter => '', :precision => 0) %>
There are more attributes available too: http://api.rubyonrails.org/classes/ActionView/Helpers/NumberHelper.html
If you want a format to be created or maintained during editing, you will need to add Javascript to implement "masks." Here is a demo.
It was the first hit in these results.
You can use the number_format plugin. By specifying a number_format for an existing numeric attribute inside your model, the attribute will now appear as formatted to Rails in all forms and views. It will also be parsed back from that format (when assigned via forms) prior to insertion into the database. (The plugin also creates purely numeric unformatted_<attribute-name> accessors which can continue to be used for arithmetic, or for direct numerical assignment or retrieval by you for seamless integration.)
class MyModel < ActiveRecord::Base
# this model has the balance attribute, which we
# want to display using formatting in views,
# although it is stored as a numeric in the database
number_format :balance,
:precision => 2,
:delimiter => ',',
:strip_trailing_zeros => false
def increment_balance
unformatted_balance += 10
end
You can also combine the above with a Javascript solution, which can force the user to maintain the decimal point and thousands separators in place while editing, although this is really not necessary.
I have done something similar. We format times and lengths using a custom form builder. It makes use of the existing text_field, but wraps it so the value can be customized:
class SuperFormBuilder < ActionView::Helpers::FormBuilder
include ApplicationHelper
include FormHelper
include ActionView::Helpers::TagHelper
include ActionView::Helpers::FormTagHelper
def length_field(label,*args)
scale = 'medium'
args.each do |v|
if v.has_key?(:scale)
scale = v[:scale]
v.delete(:scale)
end
end
value = length_conversion(#object.send(label.to_sym),scale)
options = (args.length > 0) ? args.pop : {}
return has_error(label, text_field_tag(field_name(label),value,*args) + ' ' + length_unit(scale))
end
private
def field_name(label)
return #object_name + "[#{label}]"
end
def has_error(label, output)
return "<div class='fieldWithErrors'>#{output}</div>" if #object.errors[label]
return output
end
And it is used like this:
<%= form_for( #section, {:action => 'save', :id => #section.id}, :builder => SuperFormBuilder) do |sf| %>
<%= sf.length_field :feed_size_min_w, :size => 3, :scale => 'small' %>
<% end %>
The end result is a value in the appropriate unit based off their choice on system (Metric, Imperial) and scale IE small = inches or millimeters.
I basically copied the text_field method from the existing form builder, which uses the text_field_tag itself.
There are two gotchas: 1) Knowing the name of the object field and how to access the object to get the value which you want to format. 2) Getting the name right so when the form is submitted it is part of the correct params hash.
The form builder is given a class variable #object. You can get the value of the field using the .send method. In my case I send the label :feed_size_min_w to the #object and get its length back. I then convert it to my desired format, and give it to the text_field_tag.
The name of the field is key to having it end up in the params hash, in my instance the params[:sections] one. I made a little helper function called field_name that takes care of this.
Finally the has_error wraps the field in an error div if there are errors on that label.
I needed "nicer" format on some specified text fields, resolved it by adding this to my initializers. Seems to work nicely on Rails ~= 5.2 and it should be easy to customize.
class ActionView::Helpers::Tags::TextField
private
def value_before_type_cast # override method in ActionView::Helpers::Tags::Base
v = super
# format as you like, when you like
if #options.delete(:nice_decimal)
v = v.to_s.gsub('.', ',') if v.is_a?(BigDecimal)
end
v
end
end
Usage in form f
<%= f.text_field :foo, nice_decimal: true %>
Please, can you suggest me a better way to accomplish this:
#infos = #activity.infos
#infos.each do |info|
#activity.name = info.title if info.language_id == 1
end
EDIT
In my Rails app contents can be inserted in many languages, but are displayed only in one of them. Other languages are used only as XML output.
However the main cause i'm using this approach is that without a "name" attribute i wouldn't be able to create a collection like this:
<%= collection_select(:event, :activity_id, #activities, :id, :name) %>
Can you suggest me how to accomplish this without a "name" attribute in my Activity?
Thanks!
You can do something like this.
info = #activity.infos.select{|info| info.language_id == 1}.last
#activity.name = info.title
Same as the others but using the ARrel syntax that's available in rails 3.
#activity.name = #activity.infos.where(:language_id => 1).first.title
As the others mentioned ... you might want rethink your design. If you provide more detail on why you are trying to do this we may be able to help with the underlying design that lead to this.
Well, you could lose the iteration...
#activity.name = #activity.infos.find(:first, :conditions => { :language_id => 1 }).title
but that doesn't guarantee you'll get a result (in the real world). So:
info = #activity.infos.find(:first, :conditions => { :language_id => 1 })
#activity.name = info.title unless info.nil?
But as mentioned in the comments this is a strange approach - seems like there's something structurally wrong with your app/data if you're trying to assign a value this way.
I'm trying to use the scriptaculous helper method sortable_element to implement a drag-and-drop sortable list in my Rails application. While the code for the view looks pretty simple, I'm really not quite sure what to write in the controller to update the "position" column.
Here's what I've got in my view, "_show_related_pgs.erb":
<ul id = "interest_<%=#related_interest.id.to_s%>_siblings_list">
<%= render :partial => "/interests/peer_group_map", :collection => #maps, :as => :related_pg %>
</ul>
<%= sortable_element("interest_"+#related_interest.id.to_s+"_siblings_list", :url => {:action => :resort_related_pgs}, :handle => "drag" ) %>
<br/>
And here's the relevant line from the partial, "interests/peer_group_map.erb"
<li class = "interest_<%=#related_interest.id.to_s%>_siblings_list"
id = "interest_<%=related_pg.interest_id.to_s%>_siblings_list_<%=related_pg.id.to_s%>">
The Scriptaculous UI magic works fine with these, but I am unsure as to how to change the "position" column in the db to reflect this. Should I be passing the collection #maps back to the controller and tell it to iterate through that and increment/decrement the attribute "position" in each? If so, how can I tell which item was moved up, and which down? I couldn't find anything specific using Chrome dev-tools in the generated html.
After each reordering, I also need to re-render the collection #maps since the position is being printed out next to the name of each interest (I'm using it as the "handle" specified in my call to sortable_element() above) - though this should be trivial.
Any thoughts?
Thanks,
-e
I typically create a sort action in my controller that looks like this:
def sort
order = params[:my_ordered_set]
MyModel.order(order)
render :nothing => true
end
Don't forget to add a route:
map.resources :my_model, :collection => { :sort => :put }
Now, on MyModel I add a class method that updates all of the sorted records with one query (this only works in mysql, I think..):
def self.order(ids)
update_all(
['ordinal = FIND_IN_SET(id, ?)', ids.join(',')],
{ :id => ids }
)
end
The single query method comes from Henrik Nyh.
Say I have the following model:
class Information < ActiveRecord::Base
...
validates_length_of :name, :minimum=>3, :message=>"should be longer than 3 characters!"
...
What I want to have as an error is:
Information should be longer than 3 characters! (or similar)
and NOT "Information name should be longer than 3 characters!".
Two possible workarounds I've looked at:
human_attribute_name method (mentioned here): doesn't work with my Rails 2.3.2. :-(
directly do a information.errors.add "","..." if information.name.length < 3: however, this removes many useful properties triggered by the validated_length_of method like the special class-tags (for coloring the stuff red).
Any ideas? Thank you for your time.
I suppose that you display errors through full_messages method, which is meant for console, not for web application use. You should use error_message_on or error_messages_for helpers instead (see documentation for more info), which allow you to customize error messages.
Example:
<%= error_message_on "information", "name", :prepend_text => 'Information ' %>
don't use the rails helper to make the errors, normally i have inline errors so something like:
def inline_error_block(obj, meth, prepend="", append="", klass="error error-form", &block)
content = capture(&block)
obj = (obj.respond_to?(:errors) ? obj : instance_variable_get("##{obj}"))
if obj
errors = obj.errors.on(meth.to_s)
if errors
output = content_tag(:div, :class => klass) do
content_tag(:p, "#{prepend}#{errors.is_a?(Array) ? errors.first : errors}#{append}", :class => "error-msg clearfix") + content
end
return concat(output)
end
end
concat(content_tag(:div, content, :class => "no-error"))
end
tends to do the trick, but, it only shows one error per form field, am sure you could rearrange it to show them all, should you need to! (errors.first to errors.each).
To get the full name, just write the message with the field name as you want it displayed:
validates_length_of :name, :minimum=>3, :message=>"Information should be longer than 3 characters!"
You could always set your :message to an empty string in the model then set the :prepend_text in the view to whatever you like.
I would like to make editing form fields as user-friendly as possible. For example, for numeric values, I would like the field to be displayed with commas (like number_with_precision).
This is easy enough on the display side, but what about editing? Is there a good way to do this?
I am using the Rails FormBuilder. Upon investigation, I found that it uses InstanceTag, which gets the values for fields by using <attribute>_value_before_type_cast which means overriding <attribute> won't get called.
The best I have come up with so far is something like this:
<%= f.text_field :my_attribute, :value => number_with_precision(f.object.my_attribute) %>
Or my_attribute could return the formatted value, like this:
def my_attribute
ApplicationController.helpers.number_with_precision(read_attribute(:my_attribute))
end
But you still have to use :value
<%= f.text_field :my_attribute, :value => f.object.my_attribute %>
This seems like a lot of work.
I prefer your first answer, with the formatting being done in the view. However, if you want to perform the formatting in the model, you can use wrapper methods for the getter and setter, and avoid having to use the :value option entirely.
You'd end up with something like this.
def my_attribute_string
foo_formatter(myattribute)
end
def my_attribute_string=(s)
# Parse "s" or do whatever you need to with it, then set your real attribute.
end
<%= f.text_field :my_attribute_string %>
Railscasts covered this with a Time object in a text_field in episode #32. The really clever part of this is how they handle validation errors. It's worth watching the episode for that alone.
This is an old question, but in case anyone comes across this you could use the number_to_X helpers. They have all of the attributes you could ever want for displaying your edit value:
<%= f.text_field :my_number, :value => number_to_human(f.object.my_number, :separator => '', :unit => '', :delimiter => '', :precision => 0) %>
There are more attributes available too: http://api.rubyonrails.org/classes/ActionView/Helpers/NumberHelper.html
If you want a format to be created or maintained during editing, you will need to add Javascript to implement "masks." Here is a demo.
It was the first hit in these results.
You can use the number_format plugin. By specifying a number_format for an existing numeric attribute inside your model, the attribute will now appear as formatted to Rails in all forms and views. It will also be parsed back from that format (when assigned via forms) prior to insertion into the database. (The plugin also creates purely numeric unformatted_<attribute-name> accessors which can continue to be used for arithmetic, or for direct numerical assignment or retrieval by you for seamless integration.)
class MyModel < ActiveRecord::Base
# this model has the balance attribute, which we
# want to display using formatting in views,
# although it is stored as a numeric in the database
number_format :balance,
:precision => 2,
:delimiter => ',',
:strip_trailing_zeros => false
def increment_balance
unformatted_balance += 10
end
You can also combine the above with a Javascript solution, which can force the user to maintain the decimal point and thousands separators in place while editing, although this is really not necessary.
I have done something similar. We format times and lengths using a custom form builder. It makes use of the existing text_field, but wraps it so the value can be customized:
class SuperFormBuilder < ActionView::Helpers::FormBuilder
include ApplicationHelper
include FormHelper
include ActionView::Helpers::TagHelper
include ActionView::Helpers::FormTagHelper
def length_field(label,*args)
scale = 'medium'
args.each do |v|
if v.has_key?(:scale)
scale = v[:scale]
v.delete(:scale)
end
end
value = length_conversion(#object.send(label.to_sym),scale)
options = (args.length > 0) ? args.pop : {}
return has_error(label, text_field_tag(field_name(label),value,*args) + ' ' + length_unit(scale))
end
private
def field_name(label)
return #object_name + "[#{label}]"
end
def has_error(label, output)
return "<div class='fieldWithErrors'>#{output}</div>" if #object.errors[label]
return output
end
And it is used like this:
<%= form_for( #section, {:action => 'save', :id => #section.id}, :builder => SuperFormBuilder) do |sf| %>
<%= sf.length_field :feed_size_min_w, :size => 3, :scale => 'small' %>
<% end %>
The end result is a value in the appropriate unit based off their choice on system (Metric, Imperial) and scale IE small = inches or millimeters.
I basically copied the text_field method from the existing form builder, which uses the text_field_tag itself.
There are two gotchas: 1) Knowing the name of the object field and how to access the object to get the value which you want to format. 2) Getting the name right so when the form is submitted it is part of the correct params hash.
The form builder is given a class variable #object. You can get the value of the field using the .send method. In my case I send the label :feed_size_min_w to the #object and get its length back. I then convert it to my desired format, and give it to the text_field_tag.
The name of the field is key to having it end up in the params hash, in my instance the params[:sections] one. I made a little helper function called field_name that takes care of this.
Finally the has_error wraps the field in an error div if there are errors on that label.
I needed "nicer" format on some specified text fields, resolved it by adding this to my initializers. Seems to work nicely on Rails ~= 5.2 and it should be easy to customize.
class ActionView::Helpers::Tags::TextField
private
def value_before_type_cast # override method in ActionView::Helpers::Tags::Base
v = super
# format as you like, when you like
if #options.delete(:nice_decimal)
v = v.to_s.gsub('.', ',') if v.is_a?(BigDecimal)
end
v
end
end
Usage in form f
<%= f.text_field :foo, nice_decimal: true %>