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.
Related
i'm trying (and actually succeded, but i don't understand how it works) to write a custom method for a hash in my model (I'm working on Ruby on Rails 6).
My hash looks like this
my_hash = {
[['name_1', 'slug_1']=>value_1],
[['name_2', 'slug_2']=>value_2],
[['name_1', 'slug_1']=>value_3],
[['name_2', 'slug_2']=>value_4]
}
So basically a hash of arrays. You notice that the 'keys' are arrays that repeat themselves many times, but with different values. What i want to achieve is to write a custom method that "joins" all the keys in only one key, which will have an array of values assigned, so basically i should be able to get:
my_hash = {
['name_1', 'slug_1']=>"values": [value_1, value_3],
['name_2', 'slug_2']=>"values": [value_2, value_4]
}
For that, I have this piece of code, which i use many times:
my_hash.inject({}) do |hash, record|
# each record has the following format => [["unit_name", "axis.slug"]=>average_value(float)]
keys, value = record
# now keys has ["unit_name", "axis.slug"] and values equals average_value
hash[keys.first] ||= {}
hash[keys.first][keys.last] = value.to_f
hash
end
Since I use this many times, i wanted to write a custom method, so i did:
def format_hash_data my_hash
my_hash.inject({}) do |hash, record|
# each record has the following format => [["unit_name", "axis.slug"]=>average_value(float)]
keys, value = record
# now keys has ["unit_name", "axis.slug"] and values equals average_value
hash[keys.first] ||= {}
hash[keys.first][keys.last] = value.to_f
hash
end
end
And used it like: my_hash = format_hash_data(my_hash) with no success(it threw an error saying that 'format_hash_data' was not a valid method for the class).
So I fiddled around and added 'self' to the name of the method, leaving:
def self.format_hash_data my_hash
my_hash.inject({}) do |hash, record|
# each record has the following format => [["unit_name", "axis.slug"]=>average_value(float)]
keys, value = record
# now keys has ["unit_name", "axis.slug"] and values equals average_value
hash[keys.first] ||= {}
hash[keys.first][keys.last] = value.to_f
hash
end
end
Which, to my surprise, worked flawlessly when using my_hash = format_hash_data(my_hash)
I don't really understand why adding 'self' makes my code works, maybe anyone can shed some light? I tried using things like send() or instance_eval first, to just send the piece of code to the actual hash as a method (something like my_hash.instance_eval(my_method)) but I couldn't get it working.
I'm sorry about the long explanation, I hope i was clear enough so any of you who had this same dilemma can understand. Thanks in advance.
Prepending self. to the method name makes it a class method instead of an instance method. If you are not sure of the difference, you should look it up as it is fundamental to properly defining and using classes and methods.
As a class method, you would use it as:
my_hash = MyHash.format_hash_data(my_hash)
Or if you're in scope of the class, simply my_hash = format_hash_data(my_hash), which is why it worked in your case with the self. prepended (class method definition).
If you want to define it as an instance method (a method that is defined for the instance), you would use it like so:
my_hash = my_hash.format_hash_data
And the definition would use the implicit self of the instance:
def format_hash_data
self.inject({}) do |hash, record|
# each record has the following format => [["unit_name", "axis.slug"]=>average_value(float)]
keys, value = record
# now keys has ["unit_name", "axis.slug"] and values equals average_value
hash[keys.first] ||= {}
hash[keys.first][keys.last] = value.to_f
hash
end
end
I have an array of parameters and i want to replace all parameters by looping over array in ruby on rails.
I am using before_action in controller as
before_action :cost_format
This is an array of parameters. The format of the parameter is string, i want to run a function on each parameter and convert it into float. So i am looping an array and calling function on each element.
def cost_format
x = [params[:cost_1], params[:cost_2], params[:cost_3]]
x.each do |i|
convert_cost(i)
end
end
I have a function convert_cost as following
def convert_cost(x)
x.gsub(',', '.').to_f
end
How do i loop an array so that my parameters get replaced.? Parameters are not being replaced by above code. Any hint would be appreciated.
Thanks
I think you'll want something like this:
def cost_format
%i(cost_1 cost_2 cost_3).each do |key|
params[key] = convert_cost(params[key])
end
end
def convert_cost(val)
val.gsub(',', '.').to_f
end
This grabs each key from your params and replaces the value with it passed through the convert_cost method.
Edit: you might be able to ignore this section about convert_cost due if it works with the format you're getting your numbers in. Please excuse my ethnocentrism :)
I've not updated your convert_cost method, though I'm a little wary about whether it will work at the moment. If you've got, for example "1,234,567" and you call your gsub you get "1.234.567". Calling to_f on that gives you 1.234, which I wouldn't think you'd want?
Instead of that, you could use:
def convert_cost(val)
val.gsub(',', '').to_f
end
E.G.
convert_cost("1,234,567")
# => 1234567.0
Combining all that, the following would be converted like so:
params = { cost_1: "1,234,567", cost_2: "123", cost_3: "456.5", cost_4: "I won't be touched" }
# after `cost_format` before_action runs:
# => {:cost_1=>1234567.0, :cost_2=>123.0, :cost_3=>456.5, :cost_4=>"I won't be touched"}
Let me know how you get on or if you have any question - hope this helps.
Could you try something like
x.map{|param| param.gsub(',', '.').to_f}
directly on your array.
So your cost_format method will look like:
def cost_format
x = [params[:cost_1], params[:cost_2], params[:cost_3]]
result = x.map{|param| param.gsub(',', '.').to_f}
# do stuff with result
end
I think the reason it's not working because, each method returns its receiver, but map returns a new array.
Submitting the following parameters
Parameters: {[...] "physicalinventario"=>{[...] "physicalinventarioitems_attributes"=>{"0"=>{"quantity"=>",85"}}}, "commit"
The goal is to intercept the quantity parameter at the physicalinventarioitem controller create action, and sanitize it for possible comma as decimal value being input
if params[:physicalinventario][:physicalinventarioitems_attributes][:quantity].include? ","
params[:physicalinventarioitem][:quantity] = params[:physicalinventario][:physicalinventarioitems_attributes][:quantity].tr!(',', '.').to_d
end
However, the syntax is wrong as no value after the comma is being handled.
#Alex answer is fine if you have only one quantity.
but what if you have multiple quantites,
eg: {"0"=>{"quantity"=>",85"},"1"=>{"quantity"=>",90"}}
So, here is the answer which also achieves that requirement for multiple nested attributes.
hash = {"physicalinventario"=>{"physicalinventarioitems_attributes"=>{"0"=>{"quantity"=>",85"},"1"=>{"quantity"=>",90"}}}}
The code that you require,
hash["physicalinventario"]["physicalinventarioitems_attributes"].each do |key, value|
if value["quantity"].include? ","
value["quantity"] = value["quantity"].tr!(',', '.').to_f
end
end
Here is the resultant hash,
`{"physicalinventario"=>{"physicalinventarioitems_attributes"=>{"0"=>{"quantity"=>0.85}, "1"=>{"quantity"=>0.9}}}}`
Looks like you've missed ["0"] in the chain to get :quantity.
Should be
params[:physicalinventario][:physicalinventarioitems_attribu‌tes]["0"][:quantity]
Most convenient Rails way to sanitize(normalize) data in a model.
To don't create duplicates, more here How best to sanitize fields in ruby on rails
I'm trying to loop through all the columns of a model and (1) set the value to lowercase and (2) trim it but I can't seem to get the syntax right. This is what i have so far:
#response.attributes.each do |attr_name, attr_value|
#response."#{attr_name}".downcase.strip!
end
I've searched around and can't seem to find an example of actually setting the value of the model column. All the examples I find deal with displaying the value or field name of each column. In other languages there is an evaluate or eval function to do this but I can't seem to find the equivalent in Ruby.
You can use the write_attribute method to alter an ActiveRecord attribute by name
#response.attributes.each do |attr_name, attr_value|
#response.write_attribute( attr_name, attr_value.downcase.strip )
end
Outside of ActiveRecord framework it is common to use the send method to call a bunch of accessors by name. That would work here, too:
#response.attributes.each do |attr_name, attr_value|
setter = "#{attr_name}="
#response.send( setter, attr_value.downcase.strip )
end
However, the authors of ActiveRecord have foreseen this need, and the write_attribute syntax would be my recommendation here.
You should try this code:
#response.attributes.each do |attr_name, attr_value|
#response[attr_name.to_sym] = attr_value.to_s.downcase.strip
end
Then check #response. It will assign all the values with downcase and stripped in #response variable.
I have a hash of hashes like so:
Parameters: {"order"=>{"items_attributes"=>{"0"=>{"product_name"=>"FOOBAR"}}}}
Given that the depth and names of the keys may change, I need to be able to extract the value of 'product_name' (in this example "FOOBAR") with some sort of search or select method, but I cannot seem to figure it out.
An added complication is that Params is (I think) a HashWithIndifferentAccess
Thanks for your help.
Is this what you mean?
if params.has_key?("order") and params["order"].has_key?("items_attributes") then
o = params["order"]["items_attributes"]
o.each do |k, v|
# k is the key of this inner hash, ie "0" in your example
if v.has_key?("product_name") then
# Obviously you'll want to stuff this in an array or something, not print it
print v["product_name"]
end
end
end