Rails Strong Parameters - Allow parameter to be an Array or String - ruby-on-rails

Using Strong Parameters in my Rails Controller, how can I state that a permitted parameter can be a String or an Array?
My strong params:
class SiteSearchController < ApplicationController
[...abbreviated for brevity...]
private
def search_params
params.fetch(:search, {}).permit(:strings)
end
end
I'm wanting to POST string(s) to search as a String or as an Array:
To search for 1 thing:
{
"strings": "search for this"
}
OR, to search for multiple things:
{
"strings": [
"search for this",
"and for this",
"and search for this string too"
]
}
Update:
Purpose: I'm creating an API where my users can "batch" requests (getting responses via web-hooks), or make a one-off request (getting an immediate response) all on the same endpoint. This question is only 1 small part of my requirement.
The next piece will be doing this same logic, where I'll allow the search to happen on multiple pages, i.e.:
[
{
"page": "/section/look-at-this-page",
"strings": "search for this"
},
{
"page": "/this-page",
"strings": [
"search for this",
"and for this",
"and search for this string too"
]
}
]
OR on a single page:
{
"page": "/section/look-at-this-page",
"strings": "search for this"
}
(which will make me need to have Strong Params allow an Object or an Array to be sent.
This seems like a basic thing, but I'm not seeing anything out there.
I know that I could just make the strings param an array, and then require searching for 1 thing to just have 1 value in the array... but I want to have this parameter be more robust than that.

You can just permit the parameter twice - once for an array and once for a scalar value.
def search_params
params.fetch(:search, {}).permit(:strings, strings: [])
end

You could check if params[:strings] is an array and work from there
def strong_params
if params[:string].is_a? Array
params.fetch(:search, {}).permit(strings: [])
else
params.fetch(:search, {}).permit(:strings)
end
end

Related

How can remove some special character from string of array

def valid_sheet_names
Company.find(#company_id).asset_types.pluck(:name).reject(&:nil?).map(&:downcase)
end
["hardware", "computer", "network", "mobile devices"]
this function return an array.i want to remove space, dot and underscore from string. but i don'y know how can i do this
I would filter nil values within the database query and avoid loading them into memory first. Then I would sanitize the names with one tr call:
def valid_sheet_names
Company.find(#company_id).asset_types.where.not(name: nil).pluck(:name)
names.map { |name| name.downcase.tr(' ._', '') }
end
Building off of #Sumak's #spickermann's answers
["hardware", "computer", "network", "mobile devices"].map do |asset_type|
asset_type.gsub(/[._\s]/, '')
end
Which would piece into your code like this
def valid_sheet_names
Company.find(#company_id).asset_types.pluck(:name).reject(&:nil?).map { |name| name.downcase.gsub(/[._\s]/, '') }
end
gsub is preferred here to take advantage of the metacharacter \s which grabs any type of whitespace.
The same way you map over the collection, you can iterate it using a block:
["hardware", "computer", "network", "mobile devices"].map do |asset_type|
asset_type.delete(' ')
.delete('_')
.delete('.')
end
Your function could look something like:
def valid_sheet_names
asset_types = Company.find(#company_id).asset_types.pluck(:name).reject(&:nil?)
# I'd personally extract normalization to a specific function or module
asset_types.map do |asset_type|
asset_type.downcase
.delete(' ')
.delete('.')
.delete('_')
end
end
You can also use gsub (which supports regular expressions). Though I found delete more explicit when we want to... delete

Requiring properties in array of hash without looping in Rails

In Rails 4.2, I'd like to validate that every hash of an array passed as a parameter to my action has certain attributes.
For now I could only find how to filter out unwanted attributes, such as:
ActionController::Parameters.new(
points: [{lat: 42, foo: 0}, {lng: 43, bar: 100}]
).permit(
points: [:lat, :lng]
)
# => {"points"=>[{"lat"=>42}, {"lng"=>43}]}
What I'd like to do is making sure every member of points has both lat and lng without having to loop over it. Is this possible using permit or a similar method?
There is a method called require that has the same signature as permit:
params.require(:lat, :lng)
Note that you can chain this with permit
Also, you can use select or reject on the params hash, secure params is mostly sugar for this anyway.
def my_params
required_attrs = %w{lat lng}
missing_params = required_attrs.select do |key|
params.has_key?(key)
end
missing_params.empty? ? params : raise(RuntimeError, "missing params: #{missing_params.join(",")}")
end

Editing params nested hash

Assume we have a rails params hash full of nested hashes and arrays. Is there a way to alter every string value (whether in nested hashes or arrays) which matches a certain criteria (e.g. regex) and still keep the output as a params hash (still containing nested hashes arrays?
I want to do some sort of string manipulation on some attributes before even assigning them to a model. Is there any better way to achieve this?
[UPDATE]
Let's say we want to select the strings that have an h in the beginning and replace it with a 'b'. so we have:
before:
{ a: "h343", b: { c: ["h2", "s21"] } }
after:
{ a: "b343", b: { c: ["b2", "s21"] } }
For some reasons I can't do this with model callbacks and stuff, so it should have be done before assigning to the respective attributes.
still keep the output as a params hash (still containing nested hashes arrays
Sure.
You'll have to manipulate the params hash, which is done in the controller.
Whilst I don't have lots of experience with this I just spent a bunch of time testing -- you can use a blend of the ActionController::Parameters class and then using gsub! -- like this:
#app/controllers/your_controller.rb
class YourController < ApplicationController
before_action :set_params, only: :create
def create
# Params are passed from the browser request
#model = Model.new params_hash
end
private
def params_hash
params.require(:x).permit(:y).each do |k,v|
v.gsub!(/[regex]/, 'string')
end
end
end
I tested this on one of our test apps, and it worked perfectly:
--
There are several important points.
Firstly, when you call a strong_params hash, params.permit creates a new hash out of the passed params. This means you can't just modify the passed params with params[:description] = etc. You have to do it to the permitted params.
Secondly, I could only get the .each block working with a bang-operator (gsub!), as this changes the value directly. I'd have to spend more time to work out how to do more elaborate changes.
--
Update
If you wanted to include nested hashes, you'd have to call another loop:
def params_hash
params.require(:x).permit(:y).each do |k,v|
if /_attributes/ ~= k
k.each do |deep_k, deep_v|
deep_v.gsub!(/[regex]/, 'string'
end
else
v.gsub!(/[regex]/, 'string')
end
end
end
In general you should not alter the original params hash. When you use strong parameters to whitelist the params you are actually creating a copy of the params - which can be modified if you really need to.
def whitelist_params
params.require(:foo).permit(:bar, :baz)
end
But if mapping the input to a model is too complex or you don't want to do it on the model layer you should consider using a service object.
Assuming you have a hash like this:
hash = { "hello" => { "hello" => "hello", "world" => { "hello" => "world", "world" => { "hello" => "world" } } }, "world" => "hello" }
Then add a function that transforms the "ello" part of all keys and values into "i" (meaning that "hello" and "yellow" will become "hi" and "yiw")
def transform_hash(hash, &block)
hash.inject({}){ |result, (key,value)|
value = value.is_a?(Hash) ? transform_hash(value, &block) : value.gsub(/ello/, 'i')
block.call(result, key.gsub(/ello/, 'i'), value)
result
}
end
Use the function like:
new_hash = transform_hash(hash) {|hash, key, value| hash[key] = value }
This will transform your hash and it's values regardless of the nesting level. However, the values should be strings (or another Hash) otherwise you'll get an error. to solve this problem just change the value.is_a?(Hash) conditional a bit.
NOTE that I strongly recommend you NOT to change the keys of the hash!

Constructing a nested JSON request with Jbuilder

Currently my JSON request is returning the below, where each person/lender has many inventories.
#output of /test.json
[
{"id":13, "email":"johndoe#example.com", "inventories":
[
{"id":10,"name":"2-Person Tent","category":"Camping"},
{"id":11,"name":"Sleeping bag","category":"Camping"},
{"id":27,"name":"6-Person Tent","category":"Camping"}
]
},
{"id":14, "email":"janedoe#example.com", "inventories":
[
{"id":30,"name":"Electric drill","category":"Tools"},
{"id":1,"name":"Hammer","category":"Tools"},
{"id":37,"name":"Plane","category":"Tools"}
]
}
]
I need to nest in one more thing and am having trouble doing so. For context, each inventory item is referenced via it's id as a foreign key in a borrow record. Each borrow record belongs to a request parent that stores returndate and pickupdate. What I need now, is for each inventory item, to nest an array of all the request records, with information on pickupdate and returndate. In other words, desired output:
[
{"id":13, "email":"johndoe#example.com", "inventories":
[
{"id":10,"name":"2-Person Tent","category":"Camping", "requests":
[
{"id":1, "pickupdate":"2014-07-07","returndate":"2014-07-10"},
{"id":2, "pickupdate":"2014-06-02","returndate":"2014-06-05"},
{"id":3, "pickupdate":"2014-08-14","returndate":"2014-08-20"}
]
},
{"id":11,"name":"Sleeping bag","category":"Camping", "requests":
[
{"id":4, "pickupdate":"2014-05-27","returndate":"2014-05-30"},
{"id":5, "pickupdate":"2014-04-22","returndate":"2014-04-25"}
]
},
{"id":27,"name":"6-Person Tent","category":"Camping", "requests":
[
{"id":6, "pickupdate":"2014-07-10","returndate":"2014-07-12"}
]
}
]
},
{"id":14, "email":"janedoe#example.com", "inventories":
...
I have written the following code:
json.array!(#lenders) do |json, lender|
json.(lender, :id, :email)
json.inventories lender.inventories do |json, inventory|
json.id inventory.id
json.name Itemlist.find_by_id(inventory.itemlist_id).name
#code below says, json.requests should equal all the Requests where there is a Borrows within that Request that is using the Inventory in question
json.requests Request.select { |r| r.borrows.select { |b| b.inventory_id == inventory.id }.present? } do |json, request|
json.pickupdate request.pickupdate
json.returndate request.returndate
end
end
end
When I refresh the page, I get wrong number of arguments (0 for 2..5)
I feel like the issue is that the Request.select... is returning an Array which isn't what needs to go here... but in the earlier nested function lender.inventories is an Inventory::ActiveRecord_Associations_CollectionProxy though I'm not sure how to correct for this.
NOTE: Someone said the problem could be that unlike with the nesting between inventories and lender, there's not an explicit association between inventory and request, but then again the line json.name Itemlist.find_by_id(inventory.itemlist_id).name worked so I'm not sure this is right. (Also if this is the case, I'm not sure how to bypass this limitation... I currently don't want to create a relationship between the two.)
Thanks!
ARG. Ok so this code is perfectly right. The issue was that I"m using the Gon gem in conjunction with Jbuilder, and Request is a predefined class in Gon.
So just changed code to
#requestrecords.select....
And in the controller:
#requestrecords = Request.all
-__-

Ruby on Rails: reverse lookup of array list of values

i have a model with a user selectable option that is set up in an array on the model.
def Pie < ActiveRecored::Base
def self.sel_options
[ [ "Apple Blueberry", "AB" ],
[ "Cranberry Date", "CD" ] ]
end
end
while the short string is retrieved from elsewhere and stored in the database, i would like to display the longer string when showing the object. e.g. in the view use:
Pie.display_customeor_choice[#pie_flavor]
i don't want to hard code the reverse hash, but if i create a display_options method that converts the array to a hash with reverse mapping will it run the conversion every time display_options is called? this could be resource intensive with large arrays that are converted a lot, is there a way to create the reverse hash once when the app is started and never again? (using rails 3 and ruby 1.9.2)
You are looking for Array#rassoc
Pie.display_customeor_choice.rassoc("#pie_flavor")
Here's how you could do it:
def Pie < ActiveRecored::Base
def self.sel_options
[ [ "Apple Blueberry", "AB" ],
[ "Cranberry Date", "CD" ] ]
end
def self.display_customeor_choice
unless #options
#options = {}
sel_options.each { |items| #options[items.last] = items.first }
end
#options
end
end
This guarantees it's going to be loaded only once on production (or other environments where cache_classes is set to true) but always reloads on development mode, making it simpler for you to change and see the changes.

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