I've created a form with about 40 fields available to edit, I'm trying to save them to a database using the controller. I currently have this code:
c = Form.find(params[:id])
if c
params.each do |k,v|
c.k = params[:v]
end
Which doesn't work, I get this error: undefined method 'k='
if I was going to write them all out manually it would look like this:
c = Form.find(params[:id])
if c
c.title = params[:title]
c.reference = params[:reference]
....
etc.
Assuming that you're trying to update the attributes on your Form record based on what gets passed into params, try this as a basic outline:
c = Form.find_by_id(params[:id])
if c
params.each do |k, v|
c[k] = v
end
c.save!
end
Your original code's use of params[:v] was probably not doing what you were intending, and you really meant for it to be params[:k] instead. However there's actually no need to look up the value for that key inside the loop like that because you already have the value at hand in v.
Here's a quick rundown on the ways of interacting with ActiveRecord attributes: http://www.davidverhasselt.com/2011/06/28/5-ways-to-set-attributes-in-activerecord/
i dont know what you are trying todo but your code seems to be very odd. Solution is as follow
c.send "#{k}=", params[:v]
What about
c = Form.find(params[:id])
c.update_attributes(params[:form])
Note that I guessed the [:form] part in the second line, it depends on your form. check your html source, and see if your fields are something like this:
<input name="form[field_name]" ...
As you see, name contains an "array like" form. Check your HTML source and adapt (so if its name="foo[field_name]", you need to use c.update_attributes(params[:foo]))
Related
Is it possible to dynamically create key names of a hash? I'm passing the following hash parameters:
params[:store][:store_mon_open(5i)]
params[:store][:store_mon_closed(5i)]
params[:store][:store_tue_open(5i)]
params[:store][:store_tue_closed(5i)]
.
.
.
params[:store][:store_sun_open(5i)]
params[:store][:store_sun_closed(5i)]
To check if each parameter exists, I'm using two arrays:
days_of_week = [:mon, :tue, ..., :sun]
open_or_closed = [:open, :closed]
But, I can't seem to figure out how to dynamically create the params hash (the second key( with the array. Here's what I have so far:
days_of_week.each do |day_of_week|
open_or_closed.each do |store_status|
if !eval("params[:store][:store_#{day_of_week}_#{store_status}(5i)").nil
[DO SOMETHING]
end
end
end
I've tried a bunch of things including the eval method (as listed above) but rails seems to dislike the parentheses around the "5i". Any help is greatly appreciated!
You should be able to do
if params[:store]["store_#{day_of_week}_#{store_status}(5i)".to_sym]
Note that you were missing the ? on .nil? and that !object.nil? can be shortened to just object
Assuming this is a HashWithIndifferentAccess, you should be able to access it via string just as you could with a symbol. Thus:
days_of_week.each do |day_of_week|
open_or_closed.each do |store_status|
key = "store_#{day_of_week}_#{store_status}(5i)"
unless params[:store][key]
# DO SOMETHING
end
end
end
If it's not a HashWithIndifferentAccess then you should just be able to call key.to_sym to turn it into a symbol.
I have an array with model attributes (these model attributes are columns in DB table). I am trying to iterate through this array and automatically create a record which I would like to save to DB table, something like this:
columns.each_with_index do |c, i|
user.c = data[i]
puts user.c
end
user is model.
But if I try the snippet above, I get
undefined method `c=' for #<User:0x007f8164d1bb80>
I've tried also
columns.each_with_index do |c, i|
user."#{c}" = data[i]
puts user."#{c}"
end
But this doesn't work as well.
Data in columns array are taken from form that sends user, so I want to save only data that he send me, but I still cannot figure it out...
I would like to ask you for help... thank you in advance!
user.send("#{c}=".to_sym, data[i])
Also, you can access the attributes as a hash.
user.attributes[c] = data[i]
The best thing would probably be to build a hash and to use update_attributes:
mydata = {}
columns.each_with_index{|c, i| mydata[c] = data[i]}
user.update_attributes(mydata)
this way you retain the protections provided by attr_accessible.
If this is actually in a controller, you can just make use of some basic rails conventions and build the User record like this:
#user = User.new(params[:user])
if #user.save
# do something
else
# render the form again
end
Although you can set the values using send, I agree with #DaveS that you probably want to protect yourself via attr_accessibles. If your planning to use Rails 4, here's a good overview.
I have this code that's working:
case index
when "Books"
#reading_img = res.items.first.get_hash('MediumImage')["URL"] # don't show an image
#reading_link = create_amz_url(search, asin)
tempy = #nowreading.content.match(/#nowreading.*/).to_s.gsub("#nowreading",'') # strips away the #nowreading tag
#nowreading.content = tempy.match(/#{search}.*/).to_s.gsub("#{search}", #reading_link)
# replaces the book title (passed in as variable 'search') with the URL'ed title
when "Music"
#listening_img = res.items.first.get_hash('MediumImage')["URL"] # don't show an image
#listening_link = create_amz_url(search, asin)
tempy = #nowlistening.content.match(/#nowlistening.*/).to_s.gsub("#nowlistening",'') # strips away the #nowreading tag
#nowlistening.content = tempy.match(/#{search}.*/).to_s.gsub("#{search}", #listening_link)
# replaces the song title (passed in as variable 'search') with the URL'ed title
end
I need to repeat this for many, many categories. I tried something like this to DRY the code but it didn't work:
def get_img_and_links(act, res, search, asin)
'#'+act+'ing_img' = res.items.first.get_hash('MediumImage')["URL"] # don't show an image
'#'+act+'ing_link' = create_amz_url(search, asin)
tempy = '#now'+act+'ing'.content.match(/#now"#{act}"ing.*/).to_s.gsub("#now#{act}ing",'') # strips away the #nowreading tag
'#now'+act+'ing'.content = tempy.match(/#{search}.*/).to_s.gsub("#{search}", '#'+act+'ing_link')
# replaces the book title (passed in as variable 'search') with the URL'ed title
end
Essentially, I was trying to create a function that took an "act" (e.g., "read", "listen", etc) and have the variables within that function be dynamic. Can this be accomplished? If so, how?
Look up instance_variable_set here: http://ruby-doc.org/core/classes/Object.html. It's what you need to dynamically create these variables.
instance_variable_set "##{act}ing_img".to_sym, res.items.first.get_hash('MediumImage')["URL"]
And so on...
Good looking out trying to dry up your code. I would definitely use some hashes there instead of instance variables. Then you can use the key as the action. Just a thought.
IMPO, I think you should use more generic variables. Although the creating variables are supported by ruby, it will make your code hard to read
my suggestion is having some generic names like
#img (instead of reading_img, listing_img etc..)
#link (instead of reading_link, listing_link etc..)
and something like #content, because as your login at a given time only one will be selected and this wouldn't be a problem
Again, this is what i understood from the code you posted and correct me if I'm wrong
cheers
sameera
you should do something like this:
def setup
#reading_img = get_img(whatever)
#reading_link = get_link(whatever)
#listening_img = get_img(whatever)
#listening_link = get_link(whatever)
end
def get_img(whatever)
...do stuff and return stuff...
end
def get_link(whatever)
...do stuff and return stuff...
end
I'm working on a rake task which imports from a JSON feed into an ActiveRecord called Person.
Person has quite a few attributes and rather than write lines of code for setting each attribute I'm trying different methods.
The closest I've got is shown below. This works nicely as far as outputing to screen but when I check the values have actually been set on the ActiveRecord itself it's always nil.
So it looks like I can't use .to_sym to solve my problem?
Any suggestions?
I should also mention that I'm just starting out with Ruby, have been doing quite a bit of Objective-c and now need to embrace the Interwebs :)
http = Net::HTTP.new(url.host, url.port)
http.read_timeout = 30
json = http.get(url.to_s).body
parsed = JSON.parse(json)
if parsed.has_key? 'code'
updatePerson = Person.find_or_initialize_by_code(parsed['code'])
puts updatePerson.code
parsed.each do |key, value|
puts "#{key} is #{value}"
symkey = key.to_sym
updatePerson[:symkey] = value.to_s
updatePerson.save
puts "#{key}....." # shows the current key
puts updatePerson[:symkey] # shows the correct value
puts updatePerson.first_name # a sample key, it's returning nil
end
You're probably looking for update_attributes():
if parsed.has_key?('code')
code = parsed.delete('code')
person = Person.find_or_initialize_by_code(code)
if person.update_attributes(parsed)
puts "#{person.first_name} successfully saved"
else
puts "Failed to save #{person.first_name}"
end
end
Your code can not assign any attribute, because you are always assigning to the single attribute named "symkey":
symkey = key.to_sym
updatePerson[:symkey] = value.to_s # assigns to attribute "symkey", not to the attribute with the name stored in variable symkey
If you want to make key into a symbol (which is probably not even necessary) and then use that as an index to access the attribute in updatePerson, you can write:
updatePerson[key.to_sym] = value.to_s
updatePerson.save
But this - more or less - is the same as
updatePerson.updateAttribute(key.to_sym, value.to_s) # update and save
except that no validation is triggered, so use with care.
And performancewise it might not be such a good idea to save the person after each assignment, so maybe you want to defer the .save() call until after you have assigned all attributes.
Nevertheless, updateAttributes(...) is something you might want to be looking into - if you do, do not forget to inform yourself on attr_protected or attr_accessible, as they protect attributes from "bulk assignment"
You can use write_attribute:
parsed.each do |key, value|
updatePerson.write_attribute(key, value)
end
updatePerson.save
I am trying to use a time_select to input a time into a model that will then perform some calculations.
the time_select helper prepares the params that is return so that it can be used in a multi-parameter assignment to an Active Record object.
Something like the following
Parameters: {"commit"=>"Calculate", "authenticity_token"=>"eQ/wixLHfrboPd/Ol5IkhQ4lENpt9vc4j0PcIw0Iy/M=", "calculator"=>{"time(2i)"=>"6", "time(3i)"=>"10", "time(4i)"=>"17", "time(5i)"=>"15", "time(1i)"=>"2009"}}
My question is, what is the best way to use this format in a non-active record model. Also on a side note. What is the meaning of the (5i), (4i) etc.? (Other than the obvious reason to distinguish the different time values, basically why it was named this way)
Thank you
You can create a method in the non active record model as follows
# This will return a Time object from provided hash
def parse_calculator_time(hash)
Time.parse("#{hash['time1i']}-#{hash['time2i']}-#{hash['time3i']} #{hash['time4i']}:#{hash['time5i']}")
end
You can then call the method from the controller action as follows
time_object = YourModel.parse_calculator_time(params[:calculator])
It may not be the best solution, but it is simple to use.
Cheers :)
The letter after the number stands for the type to which you wish it to be cast. In this case, integer. It could also be f for float or s for string.
I just did this myself and the easiest way that I could find was to basically copy/paste the Rails code into my base module (or abstract object).
I copied the following functions verbatim from ActiveRecord::Base
assign_multiparameter_attributes(pairs)
extract_callstack_for_multiparameter_attributes(pairs)
type_cast_attribute_value(multiparameter_name, value)
find_parameter_position(multiparameter_name)
I also have the following methods which call/use them:
def setup_parameters(params = {})
new_params = {}
multi_parameter_attributes = []
params.each do |k,v|
if k.to_s.include?("(")
multi_parameter_attributes << [ k.to_s, v ]
else
new_params[k.to_s] = v
end
end
new_params.merge(assign_multiparameter_attributes(multi_parameter_attributes))
end
# Very simplified version of the ActiveRecord::Base method that handles only dates/times
def execute_callstack_for_multiparameter_attributes(callstack)
attributes = {}
callstack.each do |name, values|
if values.empty?
send(name + '=', nil)
else
value = case values.size
when 2 then t = Time.new; Time.local(t.year, t.month, t.day, values[0], values[min], 0, 0)
when 5 then t = Time.time_with_datetime_fallback(:local, *values)
when 3 then Date.new(*values)
else nil
end
attributes[name.to_s] = value
end
end
attributes
end
If you find a better solution, please let me know :-)