How to use two different params hashes in one page (Rails) - ruby-on-rails

Hi
I want to use two params hashes in one page
The job of this page is straightforward, it's an edit page, and I want it to send out notifications to a server once the editing job is done.
def update
#description = Tempdescription.find(params[:id])
#description.update_attributes(params[:tempdescription])
sendnotification
end
def sendnotification
params[:to_ids]="xxxx"
sig = hash_params(params);
params[:sig] = sig
response = RestClient.post "http://api.xxxx.com/restserver.do", params, :content_type => :json, :accept => :json
render :text=>response
end
def hash_params(params)
params = Hash[*params.sort.flatten]
payload = ''
params.sort.each do |pair|
key, value = pair
payload = payload + "#{key}=#{value}"
end
return Digest::MD5.hexdigest(payload + API_SECRET)
end
Not surprisingly the params in sendnotification also includes params used for updating
and the server returns 104 error
Therefore,
I tried
new_params=Hash[]
and use new_params to replace the old params in sendnotification
But then rails complains
undefined method `<=>' for :session_key:Symbol
app/controllers/tempdescriptions_controller.rb:72:in `<=>'
app/controllers/tempdescriptions_controller.rb:72:in `sort'
app/controllers/tempdescriptions_controller.rb:72:in `hash_params'
app/controllers/tempdescriptions_controller.rb:45:in `sendnotification'
So I am thinking if there is any way I can create another params?
Thanks in advance

Ok, having complained about your formatting I suppose I should hazard an attempt at your problem.
This code:
def hash_params(params)
params = Hash[*params.sort.flatten]
payload = ''
params.sort.each do |pair|
key, value = pair
payload = payload + "#{key}=#{value}"
end
return Digest::MD5.hexdigest(payload + API_SECRET)
end
.. appears to accept a hash as its argument and then recreate it with the keys sorted. Presumably this code is targeted at ruby 1.9 otherwise that would be rather pointless. It then sorts again for no reason I can determine before joining the keys and values with = but without separating the pairs with &.
The error is a little mysterious though; I have no trouble sorting symbols with ruby 1.9. Perhaps you're running ruby 1.8?

Ok...after playing with rails console for a while I finally find a solution to this problem.
In sendnotification method I created a new hash
p=Hash[]
but simply putting this will not work, as I mentioned before.
Then I changed all
p[:key]
to
p["key"]
and it works.
Obviously Hash#sort doesn't work with hash[:key] if the hash is newly created but it works with params and that's what puzzled me and made me believe there is a difference between params and normal hash.
I am using Ruby 1.8.7 so I think it might just be a bug of this version.

Related

Rails: JSON attribute is handled as a method. No method error

I am having problems accessing the attributes of my JSON data. Instead of accessing the JSON data it thinks it is a function.
#response = HTTParty.get('http://localhost:4000/test')
#json = JSON.parse(#response.body)
#json.each do |pet|
MyModel.create(pet) ! WORKS
puts "my object #{pet}" ! WORKS
puts "my object attribute #{pet.myattribute}" ! DOES NOT WORK
end
With no MethodError myattribute.
Thank you for any help!
You may be used to JavaScript, where both object.some_key and object["some_key"] do the same thing. In Ruby, a hash is just a hash, so you have to access values via object["some_key"]. A Struct in Ruby is similar to a JavaScript object, in that you can access values both ways, but the keys have to be pre-defined.
#json = JSON.parse(#response.body) returns a hash, so you would need to do
puts "my object attributes #{pet['id']}, #{pet['title']}"
you might want to convert to HashWithIndifferentAccess so you can use symbols instead of quoted strings, i.e.
#json = JSON.parse(#response.body).with_indifferent_access
# ...
puts "my object attributes #{pet[:id]}, #{pet[:title]}"

Dynamically creating hash key name in Rails 4

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.

Vaccum hash from xml throws Null pointer in code, but renders fine in json

I am using vaccum to fetch product details from Amazon Product Advertising API.
req = Vacuum.new
req.configure(key: configatron.api.amazon.productAPI.key,
secret: configatron.api.amazon.productAPI.secret,
tag: 'biz-val')
regex = Regexp.new "http://([^/]+)/([\\w-]+/)?(dp|gp/product|exec/obidos/asin)/(\\w+/)?(\\w{10})"
productID=regex.match(#url).captures[4];
host=regex.match(#url).captures[0];
utype=regex.match(#url).captures[2];
#url="http://#{host}/#{utype}/#{productID}"
params = { 'Operation' => 'ItemLookup',
'ItemId' => productID,
'ResponseGroup'=>'Large'
}
res = req.get(:query => params)
hsh=Hash.from_xml(res.body)
#details=hsh
item=hsh[:ItemLookupResponse][:Items][:Item]#Throws an Undefined method [] for nilClass
You can ignore the regex parsing. I have checked it works fine.The hash that is generated from res.body is a valid hash, it shows up fine in the json rendered(#details), but throws a nilClass thing when I try to access it in the code.
I think thi might be becausehsh[:ItemLookupResponse] returns something other than a hash. I am not sure what it is returning though. How do I access :Items ?
If it says you are trying to call [] on a NilClass then it is highly likely that you are. On that particular line you call [] on these three
hsh
hsh[:ItemLookupResponse]
hsh[:ItemLookupResponse][:Items]
So one of them is, again highly likely, to be nil. You might want to use debugger/repl and put a breakpoint right before the erring line and examine hsh. I use pry, with which you woud first require 'pry' and then put binding.pry where you want the breakpoint.

Unwanted symbol to string conversion of hash key

When I assign in my controller
#my_hash = { :my_key => :my_value }
and test that controller by doing
get 'index'
assigns(:my_hash).should == { :my_key => :my_value }
then I get the following error message:
expected: {:my_key=>:my_value},
got: {"my_key"=>:my_value} (using ==)
Why does this automatic symbol to string conversion happen? Why does it affect the key of the hash?
It may end up as a HashWithIndifferentAccess if Rails somehow gets ahold of it, and that uses string keys internally. You might want to verify the class is the same:
assert_equal Hash, assigns(:my_hash).class
Parameters are always processed as the indifferent access kind of hash so you can retrieve using either string or symbol. If you're assigning this to your params hash on the get or post call, or you might be getting converted.
Another thing you can do is freeze it and see if anyone attempts to modify it because that should throw an exception:
#my_hash = { :my_key => :my_value }.freeze
You might try calling "stringify_keys":
assigns(:my_hash).should == { :my_key => :my_value }.stringify_keys
AHA! This is happening not because of Rails, per se, but because of Rspec.
I had the same problem testing the value of a Hashie::Mash in a controller spec (but it applies to anything that quacks like a Hash)
Specifically, in a controller spec, when you call assigns to access the instance variables set in the controller action, it's not returning exactly the instance variable you set, but rather, a copy of the variable that Rspec stores as a member of a HashWithIndifferentAccess (containing all the assigned instance variables). Unfortunately, when you stick a Hash (or anything that inherits from Hash) into a HashWithIndifferentAccess, it is automatically converted to an instance of that same, oh-so-convenient but not-quite-accurate class :)
The easiest work-around is to avoid the conversion by accessing the variable directly, before it's converted "for your convenience", using: controller.view_assigns['variable_name'] (note: the key here must be a string, not a symbol)
So the test in the original post should pass if it were changed to:
get 'index'
controller.view_assigns['my_hash'].should == { :my_key => :my_value }
(of course, .should is no longer supported in new versions of RSpec, but just for comparison I kept it the same)
See this article for further explanation:
http://ryanogles.by/rails/hashie/rspec/testing/2012/12/26/rails-controller-specs-dont-always-play-nice-with-hashie.html
I know this is old, but if you are upgrading from Rails-3 to 4, your controller tests may still have places where Hash with symbol keys was used but compared with the stringified version, just to prevent the wrong expectation.
Rails-4 has fixed this issue: https://github.com/rails/rails/pull/5082 .
I suggest updating your tests to have expectations against the actual keys.
In Rails-3 the assigns method converts your #my_hash to HashWithIndifferentAccess that stringifies all the keys -
def assigns(key = nil)
assigns = #controller.view_assigns.with_indifferent_access
key.nil? ? assigns : assigns[key]
end
https://github.com/rails/rails/blob/3-2-stable/actionpack/lib/action_dispatch/testing/test_process.rb#L7-L10
Rails-4 updated it to return the original keys -
def assigns(key = nil)
assigns = {}.with_indifferent_access
#controller.view_assigns.each { |k, v| assigns.regular_writer(k, v) }
key.nil? ? assigns : assigns[key]
end
https://github.com/rails/rails/blob/4-0-stable/actionpack/lib/action_dispatch/testing/test_process.rb#L7-L11
You can also pass your Hash object to the initializer of HashWithIndifferentAccess.
You can use HashWithIndifferentAccess.new as Hash init:
Thor::CoreExt::HashWithIndifferentAccess.new( to: 'mail#somehost.com', from: 'from#host.com')

Setting many key/value pairs

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

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