I am trying to restructure a named-JSON response to return a model object (some attributes only), and some associated arrays stored in local variables, however I am unsure what I'm doing incorrectly. The local variables are definitely being assigned with values, however they're not being returned in the response.
This is the structure of what I want returned...
{ name: "Dan", email: "email#email.com", id: "1", open_gifts: [ { objects }, { here }] }
Setup
#person = Person.find_by_id(params[:id])
gifts_created_open = Gift.created_gifts_open(#person)
return_object = [#person.name, #person.email, #person.id, gifts_created_open]
Now this, returns a JSON object with the details, but its wrapped in an array, and I'm trying to return just a named object, with the associated array inside it.
render :json => return_object
And this returns a named object, but its missing the array. What gives??
render :json => #person.to_json(:gifts_created_open, :only => [:name, :email, :id] )
Many thanks with this. I've already spent several hours :/
Try:
return_object = {name:#person.name, email:#person.email, id:#person.id, gifts:gifts_created_open}.to_json
Related
Introduction
Correcting a legacy code, there is an index of object LandingPage where most columns are supposed to be sortable, but aren't. This was mostly corrected, but few columns keep posing me trouble.
Theses columns are the one needing an aggregation, because based on a count of other documents. To simplify the explanation of the problem, I will speak only about one of them which is called Visit, as the rest of the code will just be duplication.
The code fetch sorted and paginate data, then modify each object using LandingPage methods before sending the json back. It was already like this and I can't modify it.
Because of that, I need to do an aggregation (to sort LandingPage by Visit counts), then get the object as LandingPage instance to let the legacy code work on them.
The problem is the incapacity to transform Mongoid::Document to a LandingPage instance
Here is the error I got:
Mongoid::Errors::UnknownAttribute:
Message:
unknown_attribute : message
Summary:
unknown_attribute : summary
Resolution:
unknown_attribute : resolution
Here is my code:
def controller_function
landing_pages = fetch_landing_page
landing_page_hash[:data] = landing_pages.map do |landing_page|
landing_page.do_something
# Do other things
end
render json: landing_page_hash
end
def fetch_landing_page
criteria = LandingPage.where(archived: false)
columns_name = params[:columns_name]
column_direction = params[:column_direction]
case order_column_name
when 'visit'
order_by_visits(criteria, column_direction)
else
criteria.order_by(columns_name => column_direction).paginate(
per_page: params[:length],
page: (params[:start].to_i / params[:length].to_i) + 1
)
end
def order_by_visit(criteria, order_direction)
def order_by_visits(landing_pages, column_direction)
LandingPage.collection.aggregate([
{ '$match': landing_pages.selector },
{ '$lookup': {
from: 'visits',
localField: '_id',
foreignField: 'landing_page_id',
as: 'visits'
}},
{ '$addFields': { 'visits_count': { '$size': '$visits' }}},
{ '$sort': { 'visits_count': column_direction == 'asc' ? 1 : -1 }},
{ '$unset': ['visits', 'visits_count'] },
{ '$skip': params[:start].to_i },
{ '$limit': params[:length].to_i }
]).map { |attrs| LandingPage.new(attrs) { |o| o.new_record = false } }
end
end
What I have tried
Copy and past the hash in console to LandingPage.new(attributes), and the instance was created and valid.
Change the attributes key from string to symbole, and it still didn't work.
Using is_a?(hash) on any element of the returned array returns true.
Put it to json and then back to a hash. Still got a Mongoid::Document.
How can I make the return of the Aggregate be a valid instance of LandingPage ?
Aggregation pipeline is implemented by the Ruby MongoDB driver, not by Mongoid, and as such does not return Mongoid model instances.
An example of how one might obtain Mongoid model instances is given in documentation.
I am creating an array of fields
def create_fields fields
fields_list = []
fields.each do |field|
# puts "adding_field to array: #{field}"
field_def = { field: field, data: { type: 'Text', description: '' } }
fields_list.push field_def
end
fields_list
end
The fields_list is being set to a jsonb field.
Lets say I pass in
create_fields ['Ford', 'BMW', 'Fiat']
Json result is an array:
{"field"=>"Ford", "data"=>{"type"=>"Text", "description"=>""}}
{"field"=>"BMW", "data"=>{"type"=>"Text", "description"=>""}}
{"field"=>"Fiat", "data"=>{"type"=>"Text", "description"=>""}}
How can I access the 'Ford' from the json array? Am i creating the array incorrectly? Is there a better way to create this array so I can access the field i want?
This assertion passes assert_equal(3, fields.count)
However i want to get 'Ford' and check it's properties, e.g. type = 'Text', type could equal 'Number' or whatever.
The result of your create_fields method with the specified parameters is the following:
[
{:field=>"Ford", :data=>{:type=>"Text", :description=>""}},
{:field=>"BMW", :data=>{:type=>"Text", :description=>""}},
{:field=>"Fiat", :data=>{:type=>"Text", :description=>""}}
]
It means that if you want to access the line belonging to "Ford", you need to search for it like:
2.3.1 :019 > arr.select{|e| e[:field] == "Ford" }
=> [{:field=>"Ford", :data=>{:type=>"Text", :description=>""}}]
2.3.1 :020 > arr.select{|e| e[:field] == "Ford" }[0][:data][:type]
=> "Text"
This is not optimal, because you need to search an array O(n) instead of using the pros of a hash. If there are e.g.: 2 "Ford" lines, you'll get an array which contains 2 elements, harder to handle collisions in field value.
It would be better if you created the array like:
def create_fields fields
fields_list = []
fields.each do |field|
# puts "adding_field to array: #{field}"
field_def = [field, { type: 'Text', description: '' } ]
fields_list.push field_def
end
Hash[fields_list]
end
If you choose this version, you can access the members like:
2.3.1 :072 > arr = create_fields ['Ford', 'BMW', 'Fiat']
=> {"Ford"=>{:type=>"Text", :description=>""}, "BMW"=>{:type=>"Text", :description=>""}, "Fiat"=>{:type=>"Text", :description=>""}}
2.3.1 :073 > arr["Ford"]
=> {:type=>"Text", :description=>""}
2.3.1 :074 > arr["Ford"][:type]
=> "Text"
Both of the above examples are Ruby dictionaries / Hashes.
If you want to create a JSON from this, you will need to convert it:
2.3.1 :077 > require 'json'
=> true
2.3.1 :078 > arr.to_json
=> "{\"Ford\":{\"type\":\"Text\",\"description\":\"\"},\"BMW\":{\"type\":\"Text\",\"description\":\"\"},\"Fiat\":{\"type\":\"Text\",\"description\":\"\"}}"
This is a structure that makes more sense to me for accessing values based on known keys:
def create_fields fields
fields_hash = {}
fields.each do |field|
fields_hash[field] = {type: 'Text', description: ''}
end
fields_hash
end
# The hash for fields_hash will look something like this:
{
Ford: {
type: "Text",
description: ""
},
BMW: {...},
Fiat: {...}
}
This will allow you to access the values like so: fields[:Ford][:type] in ruby and fields.Ford.type in JSON. Sounds like it would be easier to return an Object rather than an Array. You can access the values based on the keys more easily this way, and still have the option of looping through the object if you want.
Obviously, there are several ways of creating or accessing your data, but I'd always lean towards the developer picking a data structure best suited for your application.
In your case currently, in order to access the Ford hash, you could use the Ruby Array#detect method as such:
ford = fields_list.detect{|field_hash| field_hash['field'] == 'Ford' }
ford['data'] # => {"type"=>"Text", "description"=>""}
ford['data']['type'] # => 'Text'
So, you have result of your method:
result =
[
{"field"=>"Ford", "data"=>{"type"=>"Text", "description"=>""}},
{"field"=>"BMW", "data"=>{"type"=>"Text", "description"=>""}},
{"field"=>"Fiat", "data"=>{"type"=>"Text", "description"=>""}}
]
to get 'Ford' from it you can use simple method detect
result.detect { |obj| obj['field'] == 'Ford' }
#=> { "field"=>"Ford", "data"=>{"type"=>"Text", "description"=>""}
Also I recommend you to edit your method to make it more readable:
def create_fields(fields)
fields.map do |field|
{
field: field,
data: {
type: 'Text',
description: ''
}
}
end
end
I need to build a json object inside a loop using params.
My params look like this...
params[:answers]
returns => {"1"=>"answer1", "2"=>"answer2"}
The keys in this json object are the id's of the survey question.
So I planed to loop through the keys to build the json object like this...
def build_answersheet_json(params[:answers], params[:survey_id])
params[:answers].keys.each do |question_id|
current_question = question_id
current_answer = params[:answers][question_id]
end
end
Since im using "t.json" in my migration to save json to postgres, I wanted to use the extracted question_id and answer to build a json object that looks something like this...
{
survey_id: '1',
answers: {
question: [{
question_id: 1,
answer: 'answer1'
}, {
question_id: 2,
answer: 'answer2'
}]
}
}
Ive been trying to do this using a method that looks somthing like this...
build_answersheet_json(params[:answers], params[:survey_id])
Ive tried JSON.parse() and Ive tried to just logically work through it but I cant seem to figure this out.
Any help is appreciated.
Maybe you can try something like that:
/* fake params (to test) */
params = {
survey_id: '1',
answers: {
"1"=>"answer1",
"2"=>"answer2",
"3"=>"answer3",
"4"=>"answer4"
}
}
def build_answersheet_json(answers, survey_id)
{
survey_id: survey_id,
answers: answers.map { |k,v| { question_id: k.to_i, answer: v } }
}
end
survey = build_answersheet_json(params[:answers], params[:survey_id])
puts survey.class
#Hash
puts survey.to_json
# formated JSON string:
# {
# "survey_id":"1",
# "answers":[
# {"question_id":1,"answer":"answer1"},
# {"question_id":2,"answer":"answer2"},
# {"question_id":3,"answer":"answer3"},
# {"question_id":4,"answer":"answer4"}
# ]
# }
In order to save to a t.json postgress column type, just pass the Hash survey object, like that:
YourModel.create(survey: survey)
Source: http://edgeguides.rubyonrails.org/active_record_postgresql.html
Try
{
survey: ¯\_༼◉ل͟◉༽_/¯,
}
Json may not be parsed if json have construction like this:
survey = {
}
Json may not contain = and assignment
Check real variables values with puts varname.inspect near at code lines where you meet unexpected behaviour.
I have a SQL query returns some data, here is some sample output:
[
{
"AccountCode": "111123456",
"AccountID": 123456,
"BalanceCurrent": "-8.0",
"Phone": "123456888",
}
]
This is a Hash with an array. There are times when there will be multiple hashes within the array. Just one in this example though.
As stated, this data comes directly from the database.
I have a lookup_phone method in my Customer model that runs the SQL query and then executed in the customer_controller.rb file like so:
customer_phone = Customer.lookup_phone(params[:Phone])
Now, I need to append some extra data to these hash(es) that do not come from the database, like so:
data = [
:match_found => true,
:transfer_flag => false,
:confirm_id => 2
]
This data variable needs to be WITHIN each hash object, not a separate hash object on its own.
Using a simple array concat or + always makes the data a separate hash object. I've come across some good posts saying to use reduce along with merge, but those are Hash methods, not Array methods.
If I try to set data as a Hash instead of an array, I get
no implicit conversion of Hash into Array when I try to do
customer_phone.reduce({}, :merge)
after running customer_phone += data
What is the proper way to append data to an existing Hash object?
maybe combine each and merge
base = [
{
"AccountCode": "111123456",
"AccountID": 123456,
"BalanceCurrent": "-8.0",
"Phone": "123456888",
}
]
data = {:match_found=>true, :transfer_flag=>false, :confirm_id=>2}
base.each { |el| el.merge!(data) }
#=> [{:AccountCode=>"111123456", :AccountID=>123456, :BalanceCurrent=>"-8.0", :Phone=>"123456888", :match_found=>true, :transfer_flag=>false, :confirm_id=>2}]
You can add attr_accessor to your Customer model like this
class Customer
attr_accessor :data
end
With your data array:
data_array = [
:match_found => true,
:transfer_flag => false,
:confirm_id => 2
]
Then, you can execute the query combined with each function:
customer_phone = Customer.lookup_phone(params[:Phone]).each {|e| e.data = data_array}
Access it:
customer_phone.first.data
To render json:
render json: customer_phone, methods: [:data]
I have a UUID with three unique properties for each UUID. I want to store all these. I know I need a hash inside a hash, but I am having trouble doing this.
It's creating them inside a loop, and for each iteration I need to append/add it to the hash, so I'm not sure how to do that either.
19ee480015a2012f0aeb64ce8f2f69f4:
status: complete
name: SaveComment
pct_complete: 100
083732301597012f0aea64ce8f2f69f4:
status: working
name: SaveComment
pct_complete: 35
bf40ca301596012f0ae864ce8f2f69f4:
status: complete
name: SaveComment
pct_complete: 100
This is the code it's going into:
get '/percentcomplete' do
progress = {}
Resque::Status.status_ids.each do |uuid|
active_status = Resque::Status.get(uuid)
#update hash each loop here with name, status, pct_complete, and uuid
end
end
Assuming we can get name, status, pct_complete from active_status object,
get '/percentcomplete' do
progress = {}
Resque::Status.status_ids.each do |uuid|
active_status = Resque::Status.get(uuid)
#update hash each loop here with name, status, pct_complete, and uuid
progress[uuid.to_s] = {:name => active_status.name,
:status => active_status.status,
:ptc_complete => active_status.ptc_complete}
end
end