I am continuing my journey in learning ruby and rails. I am currently working with the tmdb gem and trying to access and then return the results of my query.
In my MovieController, I have two methods: search_tmbd and lookup_tmdb. Here is what I have:
def search_tmdb
##movie = Tmdb::Movie.find(params[:search])
#movie = Tmdb::Movie.lookup_tmdb(params[:search])
end
def self.lookup_tmdb(title)
title = params[:search]
#movie = Tmdb::Movie.find(title)
The user inputs the query in :search. When I do the query, I get this error:
undefined method `lookup_tmdb' for Tmdb::Movie:Class.
I understand I may need to pass the values in an array, but how do I work this? This one below works for me in method search_tmdb and returns the title of the movie.
#movie = Tmdb::Movie.find(params[:search])
Change definition to this
def lookup_tmdb(title)
title = params[:search]
#movie = Tmdb::Movie.find(title)
end
and thn call from other function like this
#movie = lookup_tmdb(params[:search])
Related
I have a lab through school where I need to create a form that takes in basketball team attributes, team name, coach, point guard etc., and want to know if there is any way to dynamically create instance variables and symbols using an iterator of sorts instead of hard coding them?
Here is the hard-coded version of what I mean:
post "/team" do
#name = params["name"]
#coach = params["coach"]
#pg = params["pg"]
#sg = params["sg"]
#pf = params["pf"]
#sf = params["sf"]
#c = params["c"]
erb :team
end
I want to use something similar to this:
post '/team' do
params.each do |parameter|
#[parameter] = params["#{parameter}"]
end
erb :team
end
When I run the above code I receive a unexpected end-of-input syntax error.
Try to use instance_variable_set,
something like this:
post '/team' do
params.each do |key, value|
self.instance_variable_set("##{key}", value)
end
erb :team
end
I want to access multiple columns using Rails 3.But it gave me the following error.
Error:
ArgumentError (wrong number of arguments (2 for 1)):
app/controllers/payments_controller.rb:13:in `check_type'
Check my below code.
payment_controller.rb:
class PaymentsController < ApplicationController
def payment
#payment=Vendor.new
respond_to do |format|
format.html
format.js
end
end
def check_type
if params[:commit]=="submit"
#vendor_type=PaymentVendor.where(:v_name => params[:v_name]).pluck(:type ,:Receipt_No)
#vendor_type.each do |vendor|
end
else
#v_name=Vendor.where(:s_catagory => params[:payment][:s_catagory] ).pluck(:v_name)
end
end
end
Actually i want to retrive data like below format.
#vendor_type=["Receipt_no":"type","Receipt_no":"type",.....]
Once these data will appear,I need how to access row values according to Receipt_No.Please help me to resolve this error.
Thanks to ActiveRecord >= 4 . pluck accepts multiple arguments so in
Rails 4: Your query will work
#vendor_type=PaymentVendor.where(:v_name => params[:v_name]).pluck(:type ,:Receipt_No)
Now as you are using Rails 3 which doesn't support multiple arguments to pluck then we can extend ActiveRecord::Relation itself like this:
put your file under config/initializers
# pluck_all.rb
module ActiveRecord
class Relation
def pluck_all(*args)
args.map! do |column_name|
if column_name.is_a?(Symbol) && column_names.include?(column_name.to_s)
"#{connection.quote_table_name(table_name)}.#{connection.quote_column_name(column_name)}"
else
column_name.to_s
end
end
relation = clone
relation.select_values = args
klass.connection.select_all(relation.arel).map! do |attributes|
initialized_attributes = klass.initialize_attributes(attributes)
attributes.each do |key, attribute|
attributes[key] = klass.type_cast_attribute(key, initialized_attributes)
end
end
end
end
end
Now in your controller you can pass multiple arguments to pluck like this:
# payment_controller.rb:
#vendor_type=PaymentVendor.where(:v_name => params[:v_name]).pluck_all(:type ,:Receipt_No)
Now you can use pluck_all in whole app. Hope this helps ;)
EDIT:
Try below code if plcuk_all not worked:
#vendor_type = PaymentVendor.where(:v_name => params[:v_name]).map{|v|[v.type ,v.Receipt_No]}
Reference for more info: http://meltingice.net/2013/06/11/pluck-multiple-columns-rails/
Your pluck(:type ,:Receipt_No) looks wrong,
pluck have only one argument.
Also your type of data #vendor_type is wrong, Array don't have key, value pair.
Use map like this,
#vendor_type=PaymentVendor.where(:v_name => params[:v_name]).map { |i| [i.Receipt_No] }
In terms of making a rails 3 method that behaves the same as the Rails 4 pluck with multiple columns. This outputs a similar array (rather than a hashed key value collection). This should save a bit of pain if you ever come to upgrade and want to clean up the code.
See this tutorial which outlines a similar method that outputs a hash.
config/initializers/pluck_all.rb
module ActiveRecord
class Relation
def pluck_all(*args)
args.map! do |column_name|
if column_name.is_a?(Symbol) && column_names.include?(column_name.to_s)
"#{connection.quote_table_name(table_name)}.#{connection.quote_column_name(column_name)}"
else
column_name.to_s
end
end
relation = clone
relation.select_values = args
klass.connection.select_all(relation.arel).map! do |attributes|
initialized_attributes = klass.initialize_attributes(attributes)
attributes.map do |key, attribute|
klass.type_cast_attribute(key, initialized_attributes)
end
end
end
end
end
Standing on the shoulders of giants and all
I'm trying to make a simple rss generator. My initialize method works fine and the update method runs without an error too but the new item in the update method never get added to the rss feed. I think it has something to do with how i'm accessing the variable 'maker' but i'm not sure.
require "rss"
class RSS_Engine
def initialize
#rss = RSS::Maker.make("atom") do |maker|
maker.channel.author = "Jamie"
maker.channel.updated = Time.now.to_s
maker.channel.about = "http://www.ruby-lang.org/en/feeds/news.rss"
maker.channel.title = "Example Feed"
#maker = maker
end
end
def update
#maker.items.new_item do |item|
item.title = "Test"
item.updated = Time.now.to_s
end
end
def print_rss
puts #rss
end
end
rss = RSS_Engine.new
rss.update
rss.print_rss
I got the original code from this example:
rss = RSS::Maker.make("atom") do |maker|
maker.channel.author = "matz"
maker.channel.updated = Time.now.to_s
maker.channel.about = "http://www.ruby-lang.org/en/feeds/news.rss"
maker.channel.title = "Example Feed"
maker.items.new_item do |item|
item.link = "http://www.ruby-lang.org/en/news/2010/12/25/ruby-1-9-2-p136-is-released/"
item.title = "Ruby 1.9.2-p136 is released"
item.updated = Time.now.to_s
end
This code works fine but i want to be able to add new posts to the rss feed over time so i'm trying to put the 'new.item' bit into it's own method.
The problem is not #maker variable, you have to invoke to_feed method to regenerate the feed after you modify it out of the code block.
So you need to add #rss = #maker.to_feed at the end of your update method.
One more thing about creating a new feed entry, link or id attribute need to be set.
Below code will work for you:
def update
#maker.items.new_item do |item|
item.link = "http://test.com"
item.title = "Test"
item.updated = Time.now.to_s
end
#rss = #maker.to_feed
end
If you are interested about why, you can take a look ruby rss source code. And below code(under rss/maker/base.rb) is the root cause why you need to invoke to_feed method if you modify feed out of the block:
def make(*args, &block)
new(*args).make(&block)
end
def make
yield(self)
to_feed
end
I know I'm being an idiot here, but I can't think of how this is done. I am creating an app with certain interests and am using a a Wikipedia scrape set up using Nokogiri. I have two inputs: Title and Wikipedia, but want to fill Summary and Content in the data model using the scrape. I want to use the Wikipedia attribute as a variable in a url within a method, but keep getting the error dynamic constant assignment PAGE_URL = "http://en.wikipedia.org/w/i....
I thought that the methods should go in the model, with reference to them in the Create definition under the controller, but this doesn't seem to work.
EDIT
I've just tried taking the constants out of the methods as suggested, but I am still getting a dynamic constant assignment error. My model currently looks like this:
PAGE_URL1 = "http://en.wikipedia.org/w/index.php?title="
PAGE_URL2 = "&printable=yes"
def get_PAGE_URL
PAGE_URL = PAGE_URL1 + self.wikipedia + PAGE_URL2
end
def get_page
page = Nokogiri::HTML(open(PAGE_URL))
end
def get_summary
get_PAGE_URL
self.summary = page.css("p")[0].text
end
def get_full_page
get_PAGE_URL
puts page.css('div#content.mw-body div#bodyContent div#mw-content-text.mw-content-ltr p').each do |p|
self.content = puts p.text
end
end
Constants can't go inside of methods, they must be defined inside of the class' direct scope.
Edit:
For example:
class WikiScraper
PAGE_URL = "http://www.wikipedia.org/"
def scrape
page_num = '5'
my_url = PAGE_URL + page_num
end
end
I'm trying out Rubymotion and can't seem to do figure how to accomplish what seems like a simple task.
I've set up a UITableView for a directory of people. I've created a rails back end that returns json.
Person model has a get_people class method defined:
def self.get_people
BubbleWrap::HTTP.get("http://myapp.com/api.json") do |response|
#people = BW::JSON.parse(response.body.to_str)
# p #people prints [{"id"=>10, "name"=>"Sam"}, {etc}] to the console
end
end
In the directory_controller I just want to set an instance variable for #data to the array that my endpoint returns such that I can populate the table view.
I am trying to do #data = Person.get_people in viewDidLoad, but am getting an error message that indicates the BW response object is being passed instead: undefined methodcount' for #BubbleWrap::HTTP::Query:0x8d04650 ...> (NoMethodError)`
So if I hard code my array into the get_people method after the BW response block everything works fine. But I find that I am also unable to persist an instance variable through the close of the BW respond block.
def self.get_people
BubbleWrap::HTTP.get("http://myapp.com/api.json") do |response|
#people = BW::JSON.parse(response.body.to_str)
end
p #people #prints nil to the console
# hard coding [{"id"=>10, "name"=>"Sam"}, {etc}] here puts my data in the table view correctly
end
What am I missing here? How do I get this data out of bubblewrap's response object and in to a usable form to pass to my controllers?
As explained in the BW documentation "BW::HTTP wraps NSURLRequest, NSURLConnection and friends to provide Ruby developers with a more familiar and easier to use API. The API uses async calls and blocks to stay as simple as possible."
Due to async nature of the call, in your 2nd snippet you are printing #people before you actually update it. THe right way is to pass the new data to the UI after parsing ended (say for instance #table.reloadData() if #people array is supposed to be displayed in a UITableView).
Here's an example:
def get_people
BubbleWrap::HTTP.get("http://myapp.com/api.json") do |response|
#people = BW::JSON.parse(response.body.to_str)
update_result()
end
end
def update_result()
p #people
# do stuff with the updated content in #people
end
Find a more complex use case with a more elaborate explanation at RubyMotion async programming with BubbleWrap
Personally, I'd skip BubbleWrap and go for something like this:
def self.get_people
people = []
json_string = self.get_json_from_http
json_data = json_string.dataUsingEncoding(NSUTF8StringEncoding)
e = Pointer.new(:object)
hash = NSJSONSerialization.JSONObjectWithData(json_data, options:0, error: e)
hash["person"].each do |person| # Assuming each of the people is stored in the JSON as "person"
people << person
end
people # #people is an array of hashes parsed from the JSON
end
def self.get_json_from_http
url_string = ("http://myapp.com/api.json").stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)
url = NSURL.URLWithString(url_string)
request = NSURLRequest.requestWithURL(url)
response = nil
error = nil
data = NSURLConnection.sendSynchronousRequest(request, returningResponse: response, error: error)
raise "BOOM!" unless (data.length > 0 && error.nil?)
json = NSString.alloc.initWithData(data, encoding: NSUTF8StringEncoding)
end