In my current Rails (Rails 2.3.5, Ruby 1.8.7) app, if I would like to be able to define a helper like:
def product_image_tag(product, size=nil)
html = ''
pi = product.product_images.first.filename
pi = "products/#{pi}"
pa = product.product_images.first.alt_text
if pi.nil? || pi.empty?
html = image_tag("http://placehold.it/200x200", :size => "200x200")
else
html = image_tag(pi, size)
end
html
end
...and then call it from a view with either:
<%= product_image_tag(p) %>
...or:
<%= product_image_tag(p, :size => 20x20) %>
In other words, I'd like to be able to have this helper method take an optional size parameter. What would be the best way to go about this?
You're on the right track. I would do this:
def product_image_tag(product, options = {})
options[:size] ||= "200x200"
if img = product.product_images.first
image_tag("products/#{img.filename}", :alt => img.alt_text, :size => options[:size])
else
image_tag("http://placehold.it/#{options[:size]}", :size => options[:size])
end
end
Explanations:
Setting the final parameter to an empty hash is a common Ruby idiom, since you can call a method like product_image_tag(product, :a => '1', :b => '2', :c => '3', ...) without explicitly making the remaining arguments a hash with {}.
options[:size] ||= "200x200" sets the :size parameter to 200x200 if one wasn't passed to the method.
if img = product.product_images.first - Ruby lets you do assignment inside a condition, which is awesome. In this case, if product.product_images.first returns nil (no image), you fall back to your placehold.it link, otherwise display the first image.
Related
I need to get the contents of an activerecord array into a variable.
<%= select_tag :operators,
options_for_select(#operator_list,
:selected => previous_operators(params[:id], action_name)),
),
{:multiple => true, :size => 11}
%>
previous_operators gets the contents of the operators column (an array)
def previous_operators(id, action)
if action_name != "new" && action_name != "create" # prevent error if a new bedsheet line.
#slitter_bedsheet = SlitterBedsheet.find(id) # grab the current bedsheet line
#previous_operators = Array.new
#previous_operators = #slitter_bedsheet.operators # get the keywords for the current bedsheet line
end
if #previous_operators.present?
operators = Array.new
operators = eval(#previous_operators)
else
# operators = ''
end
return operators
end
The content of operators will look something like
["", "[\"Chris Mendla\"]"]
To summarize, I am trying to get the contents of #slitter_bedsheet.operators into the selected line :selected => previous_operators(params[:id], action_name)).
So far, the selected option is not working in that no items are shown as already selected.
I solved this by using the eval function. I realize that this is a dangerous function but in this case it is an app that is inside our firewall and the input is coming from a select box. There might be another way of doing this but this will work for now.
:selected => eval(previous_operators(params[:id], action_name))
I'm a frontend + PHP dev, trying to fix [] in a project built in Rails.
[] = Fetch color, show a slightly darker color.
This row:
<%= f.text_field attribute %>
creates an input field with a value that can be translated into a color. I'm at loss as to where to look for how it adds that value. I'm trying to use the value that this input field generates.
this is code from the file select_a_color_input.html.erb inside the app/views/shared folder. Any ideas on where to continue my treasure hunt? :)
update: I found this!
def app_text_field(attribute, args = {})
render_field 'text_field', field_locals(attribute, args)
end
Does that help? ^__^
update:
The form builder
class AppFormBuilder < ActionView::Helpers::FormBuilder
def form_fields(partial = nil , options = {})
partial ||= 'form'
fields = ''
unless options.delete(:without_error_messages)
fields << #template.render('shared/error_messages', :target => Array(#object).last)
end
fields << #template.render(partial, options.merge(:f => self))
end
def app_text_field(attribute, args = {})
render_field 'text_field', field_locals(attribute, args)
end
def app_file_field(attribute, args = {})
render_field 'file_field', field_locals(attribute, args)
end
private
def render_field(name, locals)
#template.render field_path(name), locals
end
def field_locals(attribute, args = {})
help_options = args[:help_options] || {}
field_options = args[:field_options] || {}
html_options = args[:html_options] || {}
{ :f => self, :attribute => attribute, :help_options => help_options, :field_options => field_options, :html_options => html_options, :object => object }
end
def field_path(value)
"shared/app_form/#{value}"
end
end
update:
When I tried to add
<%= content_tag(:p, attribute) %>
It does not give me the values, but instead the id/name of the item, not the colour.
<%= f.text_field attribute %>
This by itself is not very useful to help us gather context. What's the surrounding markup look like? attribute is a ruby variable in this instance. If it were f.text_field :attribute, then :attribute is now a symbol instead of a variable and this would indicate that it maps to the attribute method on X model. This all depends on what your form_for looks like though. I'll give an example:
<%= form_for #user do |f| %>
<%= f.text_field :attribute %>
In this case, we have a form for the User model, and our text_field maps to #user.attribute. The field itself looks something like this:
<input type='text' name='user[attribute]'>
And in the controller's #update or #create action (depending on if this is a new record or an existing record you're editing) the value would be accessible in this fashion:
params[:user][:attribute]
However, it's impossible to say what exactly the params will look like in your particular case. What action is being run? What's the name of the file that this is being loaded from? "app/views/users/new" would indicate the #new action handles this page, and the #create action will handle the form submission.
Things we need to know to fully solve your problem:
Name and relevant code of the controller that's handling this action.
Full view path that this is being rendered from
The rest of the markup starting at form_for and ending at this field attribute
What value does attribute hold? It's a variable, so it must be holding a symbol value or something that will indicate which field is being mapped to this input.
I want to create the following loop in rails:
If value<=5
display image1.gif value.times && display image2.gif (5-value).times
I was trying to add this to my View, but is there a way I can convert it into a method? How would I put the image tags if I where to make it a helper method?
Thanks in advance for any help.
def show_starts(value)
if value <= 5
image_tag("image1.gif")*value + image_tag("image2.gif")*(5-value)
end
end
This should work if I'm understanding what you're looking for.
Put this in a helper file:
def image_helper(value, image1, image2)
html = ''
if value <= 5
value.times { html += image_tag(image) }
(5 - value).times { html += image_tag(image2) }
end
html.html_safe
end
Then call it from your view like like:
image_helper(value, 'image1.gif', 'image2.gif')
(For star rating system)
Got it working like this:
def display_stars content_tag :span, :class => 'stars' do
current_admin_rating.times do
concat(image_tag("image1.gif";, :size => "30x30", :class => "gold"))
end
(5-current_admin_rating).times do
concat(image_tag("image2.gif";, :size => "30x30", :class => "gold"))
end
nil
end
I'm creating an application that'll display a random picture based upon a defined letter in a word.
Images are attached to a Pictures model (containing another "letter" field) using Paperclip, and will be iterated through in an each block.
How would I go about passing the letter back from the each block to the model for random selection.
This is what I've come up with so far, but it's throwing the following error.
undefined method `%' for {:letter=>"e"}:Hash
Model:
def self.random(letter)
if (c = count) != 0
find(:first, :conditions => [:letter => letter], :offset =>rand(c))
end
end
View:
<% #letters.each do |a| %>
<%= Picture.random(a).image(:thumb) %>
<% end %>
Thanks
One problem is your conditions has a syntax error. The hash notation is wrong:
:conditions => [:letter => letter]
should be
:conditions => {:letter => letter}
Also, it seems to me that your random scope will always exclude the first Picture if you don't allow an offset of 0. Besides that, do you really want to return nil if the random number was 0?
Picture.random(a).image(:thumb) would throw "undefined method 'image' for nil:NilClass" exception every time c==0. Can probably just use:
def self.random(letter)
find(:first, :conditions => {:letter => letter}, :offset =>rand(count))
end
EDIT: You'll either need to guarantee that your db has images for all letters, or tell the user no image exists for a given letter.
<% #letters.each do |a| %>
<% if pic = Picture.random(a).image(:thumb) %>
<%= pic.image(:thumb) %>
<% else %>
No image available for <%= a %>
<% end %>
<% end %>
Or the like...
EDIT: Actually I don't think your offset strategy will work. One other approach would be to return the set of images available for the given letter and randomly select from that collection, something like:
def self.random(letter)
pics = find(:all, :conditions => {:letter => letter})
pics[rand(pics.size)] if !pics.blank?
end
I am trying to pass some filters in my params through a form like so:
hidden_field_tag "filters", params[:filters]
For some reason the params get changed in the next page. For example, if params[:filters] used to be...
"filters"=>{"name_like_any"=>["apple"]} [1]
...it gets changed to...
"filters"=>"{\"name_like_any\"=>[\"apple\"]}" [2]
note the extra quotations and backslashes in [2] when compared to [1].
Any ideas? I'm attempting to use this with searchlogic for some filtering, but I need it to persist when I change change objects in forms. I would prefer not to have to store it in session.
My solution was just to re-create each of param with key-value pair:
<% params[:filters].each do |key,value| %>
<%= hidden_field_tag "filters[#{key}]",value %>
<% end %>
You actually want/need to 'serialize' a hash using hidden fields.
Add this to your ApplicationHelper :
def flatten_hash(hash = params, ancestor_names = [])
flat_hash = {}
hash.each do |k, v|
names = Array.new(ancestor_names)
names << k
if v.is_a?(Hash)
flat_hash.merge!(flatten_hash(v, names))
else
key = flat_hash_key(names)
key += "[]" if v.is_a?(Array)
flat_hash[key] = v
end
end
flat_hash
end
def flat_hash_key(names)
names = Array.new(names)
name = names.shift.to_s.dup
names.each do |n|
name << "[#{n}]"
end
name
end
def hash_as_hidden_fields(hash = params)
hidden_fields = []
flatten_hash(hash).each do |name, value|
value = [value] if !value.is_a?(Array)
value.each do |v|
hidden_fields << hidden_field_tag(name, v.to_s, :id => nil)
end
end
hidden_fields.join("\n")
end
Then, in view:
<%= hash_as_hidden_fields(:filter => params[:filter]) %>
This should do the trick, even if you have a multilevel hash/array in your filters.
Solution taken http://marklunds.com/articles/one/314
I just wrote a gem to do this called HashToHiddenFields.
The core of the gem is this code:
def hash_to_hidden_fields(hash)
query_string = Rack::Utils.build_nested_query(hash)
pairs = query_string.split(Rack::Utils::DEFAULT_SEP)
tags = pairs.map do |pair|
key, value = pair.split('=', 2).map { |str| Rack::Utils.unescape(str) }
hidden_field_tag(key, value)
end
tags.join("\n").html_safe
end
Here's how I managed to pass a parameter value through my view - that is, from View A through View B and on to the controller:
In View A (index):
<%= link_to 'LinkName', {:action => "run_script", :id => object.id} %>
In View B (run_script):
<%= form_tag :action => 'index', :id => #object %>
<%= hidden_field_tag(:param_name, params[:id]) %>
In the controller:
Just reference params[:param_name] to make use of the value.
The key transition that wasn't documented anywhere I could find is where {... :id => object.id} from View A is passed on to View B as <%... :id => #object %>, which View B then passes on to the controller as (:param_name, params[:id]) through the hidden_field_tag construct.
I didn't see this documented anywhere but after perusing several posts across several sites including this post (whose syntax provided the key inspiration), the solution finally gelled. I've seen the caveats on hidden fields pertaining to security but have found no other way to do this given my current design, such as it is.
it's because when you convert in HTML with your hidden_field_tag, the backquote is add. After when you received it like a string not a Hash.
The Hash type can't exist in HTML. You have only string. So if you want pass your hash (not recommend by me), you need eval it when you received it. But can be a big security issue on your application.
As a caveat to Vlad's answer, I had to use raw:
<%= raw hash_as_hidden_fields(:filter => params[:filter]) %>
to get it to work in Rails 3.1.1. Essentially, the text being output was being escaped, eg., "<" becoming "<".
Assuming the hash is strings, symbols, numbers, and arrays, you can call eval to convert the params string of the hash from the hidden_fields form back into a hash in the controller. Then the backslash escape characters for the quotes added are no longer an issue:
hash = eval(params["hash_string"].to_s)
Credit to the following article for helping identify this simple solution for my case:
How do I convert a String object into a Hash object?
Keep in mind the contents of the params should be cleaned with .require and .permit.