Here is my code:
<%= DimensionVersion.where(:dimension_id => 1).select("name") %>
I expect to get a list of dimension version names where :dimension_id => 1. There are four in the database.
Instead I get this:
#<ActiveRecord::Relation:0x3d351c8>
EDIT:
I figured out how to return what I wanted (sort of) with this:
<%= DimensionVersion.select("name").where(:dimension_id => 1).all %>
Which returns:
[#<DimensionVersion name: "Default">, #<DimensionVersion name: "Test1">, #<DimensionVersion name: "Test2">, #<DimensionVersion name: "Test3">]
However, I don't want it returned with #<DimensionVersion Name: ... >. I tried removing = from the leading tag, but then nothing returned.
DimensionVersion.where(:dimension_id => 1).select("name")
I think you need the pluck method.
Rewrite the above as:
DimensionVersion.where(:dimension_id => 1).pluck(:name)
Similarly even a higher level construct like collect can be used as:
DimensionVersion.where(:dimension_id => 1).collect(&:name)
Hope this helps.
AR returns Relation so that you can chain conditions etc. If you want the actual results, call #all, #first, #each,... on it:
DimensionVersion.where(:dimension_id => 1).select("name").all
Querying with rails is such a pain in the butt I'm about to abandon the whole framework and go back to php.
You might want to read the guides: Active Record Query Interface.
I was able to get rid of the column names by using the collect method like so:
DimensionVersion.select("name").where(:dimension_id => 1).all.collect { |d| [d.name]}
Related
Using globalize gem to manage translations with autocomplete, there is a situation where a number of hooks need to be properly set. Note: this does not use hstore AFAIK. I have not managed to find a way to do so. The most productive set-up to date has
controller:
autocomplete :nation, :name, :full => true
Nation
translates :name
view
<%= autocomplete_field_tag 'nation_name', '', autocomplete_nation_name_itins_path, size: 35, :id_element => 'nation_id' %>
There is no inherent reference to nation_translations database table created by Globalize as of yet. As this image suggests, there is a problem:
Issue 1: The input remains binded to the base table's attribute value (I have not yet cleared them out as the Globalize gem suggests. Otherwise I'd be getting blanks). can is actually ready all values of canin master table... Typing in other locales, like cyrillic say Канада has naturally no effect as that value is not part of the Nation table.
What is interesting is that the drop-down values are being populated by Rails automatically, extracting the translation values of what is input.
Issue 2: I'd rather pass the parameter 'nation_id' which is naturally part of the nation_translations table with the form data. although I can append , :extra_data => [:nation_id] to the controller it is not being submitted (example in cyrillic where the input is given without any autocomplete)
{"utf8"=>"✓", "nation_name"=>"Канада", "commit"=>"..."}
Rails.logger.info :extra_data returns:
extra_data
Now the second issue can be overcome because a query like
Nation::Translation.where('name = ?', "Канада").pluck('nation_id')
returns a proper result. But that point is moot if the autocomplete is not playing ball with the user's input.
How can this be configured to have user input autocomplete with the current local translations?
this does get solved by creating an entirely new class with attributes nation_id, name, locale and can thus be called symbolically.
The query call is not that straightforward however. As the gem suggests, the method need to be tweaked
def autocomplete_nation_name
term = params[:term].downcase
locale = params[:locale]
nationtranslations = Nationtranslation.where('locale = ? AND name LIKE ?', locale, "%#{term}%").order(:name).all
render :json => nationtranslations.map { |nationtranslation| {:id => nationtranslation.id, :label => nationtranslation.name, :value => nationetranslation.name} }
end
intervening on the action method itself provides all the leeway desired...
I'm working on a legacy project that is using acts_as_taggable_on which expects tags to come in arrays. I have a select box allowing users to select a tag on a Course in a field called categories. The only way mass assignment create will work is if params looks like this params = {:course => {:categories => ['Presentation']}}. I've currently a view with this helper:
<%= f.select 'categories', ['Presentation' , 'Round Table' , 'Demo', 'Hands-on'] %>
Which will give me a parameter like params = {:course => {:categories => 'Presentation'}}. This doesn't work since Acts as tag gable apparently can't handle being passed anything other than a collection.
I've tried changing categories to categories[] but then I get this error:
undefined method `categories[]' for #<Course:0x007f9d95c5b810>
Does anyone know the correct way to format my select tag to return an array to the controller? I'm using Rails 3.2.3
I didn't work with acts_as_taggable_on, but maybe this simple hack will be suitable for you? You should put it before mass-assignment.
category = params[:course][:categories]
params[:course][:categories] = [category]
If you are only going to allow the selection of ONE tag, you could do:
<%= f.select 'categories', [['Presentation'] , ['Round Table'] , ['Demo'], ['Hands-on']] %>
Each one item array will have first for the display value, and last for the return value, which in this case will both return the same thing, as the first element of the array is the same as the last element when the array as one element.
Seems like select doesn't give you that option.
If I understand correctly, one option might be to use a select_tag instead and just be explicit about where you want the selection in the params:
<%= select_tag 'course[categories][]', options_for_select(['Presentation' , 'Round Table' , 'Demo', 'Hands-on']) %>
That ought to get your params the way you need them.
Here's what I'm using for one of my projects:
<% options = { include_blank: true } %>
<% html_options = { required: true, name: "#{f.object_name}[#{resource.id}][days][]" } %>
<%= f.select :days, DAYS, options, html_options %>
Without html_options[:name], Rails handles the name of the select tag and spits out something like
service[service_add_ons_attributes][11][days]
but I need
service[service_add_ons_attributes][11][days][]
So I override it.
Hope that helps.
I'm searching a gem for Rails for alphabetical pagination. I wish I could have a list of first letters found in the result (I mean, if there is no row beginning with 'a', I don't want the 'a' to be display on the pagination links). Is this kind of gem already exists?
Thanks in advance!
This wouldn't be too hard to create at all, for example if you had a find, maybe like:
#all_words = Word.select("words.word")
…which returned a result a result set such as a list of words like this:
["alphabet", "boy", "day", "donkey", "ruby", "rails", "iPad"]
…the you could do this:
#all_words.collect {|word| word[0,1]}.uniq.sort
which would return:
["a", "b", "d", "r", "i"]
The .collect {|word| word[0,1]} stores the first letter of each word into a new array whilst uniq filters out the unique letters and sort sorts these alphabetically.
Simply assign this to a variable and you can use it in your view like so:
<ul>
<% #first_letters.each do |letter| %>
<%= content_tag :li, link_to(letter, words_pagination_url(letter), :title => "Pagination by letter: #{letter}") %>
<% end %>
</ul>
Your controller action could then decide what to do with the param from the pagination if one is passed in:
def index
if params[:letter]
#words = Word.by_letter(params[:letter])
else
#words = Word.all
end
end
And then the scope in your model would look something like:
scope :by_letter,
lambda { |letter| {
:conditions => ["words.word LIKE ?", "#{letter}%"]
}}
Your routes require something like:
match "words(/:letter)" => "words#index", :as => words_pagination
I haven't tested this all the way through but it should set you on the right path.
To get a dynamic select from the appropriate table, you can use a dynamic SQL finder.
In this example, we select from a table named 'albums', and fabricate a column 'name' to hold the values. These will be returned in the 'Album' model object. Change any of these names to suit your needs.
Album.find_by_sql("SELECT DISTINCT SUBSTR(name,1,1) AS 'name' FROM albums ORDER BY 1")
Note that you can't use the Album model objects for anything except querying the 'name' field. This is because we've given this object a lobotomy by only populating the 'name' field - there's not even a valid 'id' field associated!
I've created an alphabetical pagination gem here:
https://github.com/lingz/alphabetical_paginate
For anyone still having issues in this domain.
I want to perform an if condition where, if linkedpub.LPU_ID is found in an array of values(#associated_linked_pub), do some action.
I tried the following but the syntax is not correct.
Any suggestion is most welcomed..Thanks a lot
<% for linkedpub in Linkedpub.find(:all) %>
<% if linkedpub.LPU_ID IN #associated_linked_pub %>
# do action
<%end%>
<%end%>
You can use Array#include?
So...
if #associated_linked_pub.include? linkedpub.LPU_ID
...
Edit:
If #associated_linked_pub is a list of ActiveRecord objects then try this instead:
if #associated_linked_pub.map{|a| a.id}.include? linkedpub.LPU_ID
...
Edit:
Looking at your question in more detail, it looks like what you are doing is VERY inefficient and unscalable. Instead you could do...
For Rails 3.0:
Linkedpub.where(:id => #associated_linked_pub)
For Rails 2.x:
LinkedPub.find(:all, :conditions => { :id => #associated_linked_pub })
Rails will automatically create a SQL IN query such as:
SELECT * FROM linkedpubs WHERE id IN (34, 6, 2, 67, 8)
linkedpub.LPU_ID.in?(#associated_linked_pub.collect(&:id))
Using in? in these cases has always felt more natural to me.
if #associated_linked_pub is an array, try
if #associated_linked_pub.include?(linkedpub.LPU_ID)
#associated_linked_pub.collect(&:id).include?(linkedpub.LPU_ID)
I am using simple_form and have a following sample tag:
<%= f.input :medical_conditions, :label=>false, :collection => medical_conditons, :as => :check_boxes%>
The collection holds about 100 checkboxes. However, when user only selects 1 or 2, everything is still getting saved to the database like this:
---
- ""
- ""
- ""
medical_conditions is a simple array in my application_helper
def medical_conditons
t = [
"Allergies/Hay Fever",
"Diabetes",
"Heart Surgery"]
return t
end
the medical_conditions field is a :string field.
What do I need to do so that only values that are selected are saved in comma separated manner.
It is not simple_form behavior. It is from Rails. See this: http://d.pr/6O2S
Try something like this in your controller (guessing at how you wrote your create/update methods)...
params[:medical_conditions].delete('') #this will remove the empty strings
#instance.update_attribute(:medical_conditions, params[:medical_conditions].join(','))
#or however you want to save the input, but the key is the .join(',') which will
#create a comma-separated string of only the selected values, which is exactly
#what you're looking for me thinks :-)
If that does the trick for you, I'd consider making a private helper method that formats the params for you so that you can use it in #create, #update, or wherever else you need it. This should keep things a little cleaner and more "rails way-ish" in your crud actions.