Trouble getting Rails API to display 'show' record - ruby-on-rails

I have a rails 5.2 API. I'm able to display the list of 'blogs' at site.com/blogs.json but when I try to show an individual blog at site.com/blogs/blog-1.json I get a 500 server error.
blogs_controller.rb
def show
#blog.punch(request)
#meta_title = meta_title #blog.title
respond_to do |format|
format.html
format.json
end
end
I'm using jbuilder in the Rails view directory, and it's here I suspect I have something wrong, but can't see what.
_blog.json.jbuilder
json.array! #blogs, :id, :title, :text, :created_at, :updated_at, :url
json.url blog_url(blog, format: :json)
index.json.jbuilder
json.array! #blogs
show.json.jbuilder
json.partial! "blogs/blog", blog: #blog

Related

Access images in React through Rails Active Storage using JSON

I'm making a Rails API where I would like to use Active Storage to attach images to posts and then be able to access them in REACT, such as getting the url link in JSON. How do I convert the Active Storage images to urls for JSON. Is there a better way to be able to get the link to the images for the posts?
For example, I would want the image url to be included in this information:
From: http://localhost:3001/api/posts
[{"id":8,"title":"lolol","body":"lolol","created_at":"2018-07-19T23:36:27.880Z","updated_at":"2018-07-20T00:17:50.201Z","admin_user_id":1,"post_type":"Song","link":"dgdadg","song_title":"dgdadg","tag_list":[]},{"id":13,"title":"ddd","body":"dd","created_at":"2018-07-20T00:21:39.903Z","updated_at":"2018-07-20T00:21:39.907Z","admin_user_id":1,"post_type":"Song","link":"dddd","song_title":"ddd","tag_list":["Tag"]}]
Here is my Post Controller :
class PostsController < ApiController
before_action :set_post, only: [:show, :update, :destroy]
def index
if params[:tag]
#posts = Post.tagged_with(params[:tag])
else
#posts = Post.all
end
render :json => #posts
end
def show
#post
render :json => #post
end
def create
#post = Post.new(post_params)
end
def update
#post.update(post_params)
head :no_content
end
def destroy
#post.destroy
head :no_content
end
private
def post_params
params.require(:post).permit(:title, :body, :song_title, :post_type, :admin_user_id, :link, :tag_list, :image)
end
def set_post
#post = Post.find(params[:id])
end
end
Any suggestions would be greatly appreciated.
Have been there like 2 weeks ago and decided against ActiveStorage because of the exact same issue. You can do some controller magic that uses
url_for(#post.image)
like
render :json => #post.merge({image: url_for(#post.image)})
or something along those lines
class Post
def image_url
Rails.application.routes.url_helpers.rails_blob_path(self.image, only_path: true)
end
end
# controller
render :json => #post.as_json(methods: :image_url)
It's possible within jbuilder to access the url_for helper. So your _post.json.jbuilder could work something like this
json.extract! post, :id, :body, :created_at, :updated_at
if post.image.attached?
json.image_url url_for(post.image)
end
json.url product_url(product, format: :json)
If your Post model has an ActiveStorage::Attachment you can just call
#post.file.service_url or #post.file.public_url assuming you have has_one_attached :file in your model.

In Rails How to display errors in my comment form after I submit it?

I have a very straight-forward task to fulfil --- just to be able to write comments under posts and if the comments fail validation display error messages on the page.
My comment model uses a gem called Acts_as_commentable_with_threading, which creates a comment model after I installed.
On my post page, the logic goes like this:
Posts#show => display post and a form to enter comments => after the comment is entered, redisplay the Post#show page which has the new comment if it passes validation, otherwise display the error messages above the form.
However with my current code I can't display error messages if the comment validation fails. I think it is because when I redisplay the page it builds a new comment so the old one was erased. But I don't know how to make it work.
My codes are like this:
Comment.rb:
class Comment < ActiveRecord::Base
include Humanizer
require_human_on :create
acts_as_nested_set :scope => [:commentable_id, :commentable_type]
validates :body, :presence => true
validates :first_name, :presence => true
validates :last_name, :presence => true
# NOTE: install the acts_as_votable plugin if you
# want user to vote on the quality of comments.
#acts_as_votable
belongs_to :commentable, :polymorphic => true
# NOTE: Comments belong to a user
belongs_to :user
# Helper class method that allows you to build a comment
# by passing a commentable object, a user (could be nil), and comment text
# example in readme
def self.build_from(obj, user_id, comment, first_name, last_name)
new \
:commentable => obj,
:body => comment,
:user_id => user_id,
:first_name => first_name,
:last_name => last_name
end
end
PostController.rb:
class PostsController < ApplicationController
before_action :authenticate_user!, except: [:index, :show]
def show
#post = Post.friendly.find(params[:id])
#new_comment = Comment.build_from(#post, nil, "", "", "")
end
end
CommentsController:
class CommentsController < ApplicationController
def create
#comment = build_comment(comment_params)
respond_to do |format|
if #comment.save
make_child_comment
format.html
format.json { redirect_to(:back, :notice => 'Comment was successfully added.')}
else
format.html
format.json { redirect_to(:back, :flash => {:error => #comment.errors}) }
end
end
end
private
def comment_params
params.require(:comment).permit(:user, :first_name, :last_name, :body, :commentable_id, :commentable_type, :comment_id,
:humanizer_answer, :humanizer_question_id)
end
def commentable_type
comment_params[:commentable_type]
end
def commentable_id
comment_params[:commentable_id]
end
def comment_id
comment_params[:comment_id]
end
def body
comment_params[:body]
end
def make_child_comment
return "" if comment_id.blank?
parent_comment = Comment.find comment_id
#comment.move_to_child_of(parent_comment)
end
def build_comment(comment_params)
if current_user.nil?
user_id = nil
first_name = comment_params[:first_name]
last_name = comment_params[:last_name]
else
user_id = current_user.id
first_name = current_user.first_name
last_name = current_user.last_name
end
commentable = commentable_type.constantize.find(commentable_id)
Comment.build_from(commentable, user_id, comment_params[:body],
first_name, last_name)
end
end
comments/form: (this is on the Posts#show page)
<%= form_for #new_comment do |f| %>
<% if #new_comment.errors.any? %>
<div id="errors">
<h2><%= pluralize(#new_comment.errors.count, "error") %> encountered, please check your input.</h2>
<ul>
<% #new_comment.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<% end %>
I would instead use nested routes to create a more restful and less tangled setup:
concerns :commentable do
resources :comments, only: [:create]
end
resources :posts, concerns: :commentable
This will give you a route POST /posts/1/comments to create a comment.
In your controller the first thing you want to do is figure out what the parent of the comment is:
class CommentsController < ApplicationController
before_action :set_commentable
private
def set_commentable
if params[:post_id]
#commentable = Post.find(params[:post_id])
end
end
end
This means that we no longer need to pass the commentable as form parameters. Its also eliminates this unsafe construct:
commentable = commentable_type.constantize.find(commentable_id)
Where a malicous user could potentially pass any class name as commentable_type and you would let them find it in the DB... Never trust user input to the point where you use it to execute any kind of code!
With that we can start building our create action:
class CommentsController < ApplicationController
before_action :set_commentable
def create
#comment = #commentable.comments.new(comment_params) do |comment|
if current_user
comment.user = current_user
comment.first_name = current_user.first_name
comment.last_name = current_user.last_name
end
end
if #comment.save
respond_to do |format|
format.json { head :created, location: #comment }
format.html { redirect_to #commentable, success: 'Comment created' }
end
else
respond_to do |format|
format.html { render :new }
format.json { render json: #comment.errors, status: 422 }
end
end
end
private
# ...
def comment_params
params.require(:comment).permit(:first_name, :last_name, :body, :humanizer_answer, :humanizer_question_id)
end
end
In Rails when the user submits a form you do not redirect the user back to the form - instead you re-render the form and send it as a response.
While you could have your CommentsController render the show view of whatever the commentable is it will be quite brittle and may not even provide a good user experience since the user will see the top of the post they where commenting. Instead we would render app/views/comments/new.html.erb which should just contain the form.
Also pay attention to how we are responding. You should generally avoid using redirect_to :back since it relies on the client sending the HTTP_REFERRER header with the request. Many clients do not send this!
Instead use redirect_to #commentable or whatever resource you are creating.
In your original code you have totally mixed up JSON and HTML responses.
When responding with JSON you do not redirect or send flash messages.
If a JSON POST request is successful you would either:
Respond with HTTP 201 - CREATED and a location header which contains the url to the newly created resource. This is preferred when using SPA's like Ember or Angular.
Respond with HTTP 200 - OK and the resource as JSON in the response body. This is often done in legacy API's.
If it fails do to validations you should respond with 422 - Unprocessable Entity - usually the errors are rendered as JSON in the response body as well.
Added.
You can scrap your Comment.build_from method as well which does you no good at all and is very idiosyncratic Ruby.
class PostsController < ApplicationController
before_action :authenticate_user!, except: [:index, :show]
def show
#post = Post.friendly.find(params[:id])
#new_comment = #post.comments.new
end
end
Don't use line contiuation (\) syntax like that - use parens.
Don't:
new \
:commentable => obj,
:body => comment,
:user_id => user_id,
:first_name => first_name,
:last_name => last_name
Do:
new(
foo: a,
bar: b
)
Added 2
When using form_for with nested resources you pass it like this:
<%= form_for([commentable, comment]) do |f| %>
<% end %>
This will create the correct url for the action attribute and bind the form to the comment object. This uses locals to make it resuable so you would render the partial like so:
I'm assuming your form_for submits a POST request which triggers the HTML format in CommentsController#create:
def create
#comment = build_comment(comment_params)
respond_to do |format|
if #comment.save
make_child_comment
format.html
format.json { redirect_to(:back, :notice => 'Comment was successfully added.')}
else
format.html
format.json { redirect_to(:back, :flash => {:error => #comment.errors}) }
end
end
end
So, if #comment.save fails, and this is an HTML request, the #create method renders create.html. I think you want to render Posts#show instead.
Keep in mind that if validations fail on an object (Either by calling save/create, or validate/valid?), the #comment object will be populated with errors. In other words calling #comment.errors returns the relevant errors if validation fails. This is how your form is able to display the errors in #new_comment.errors.
For consistency, you'll need to rename #new_comment as #comment in the posts#show action, otherwise you'll get a NoMethodError on Nil::NilClass.
TL;DR: You're not rendering your form again with your failed #comment object if creation of that comment fails. Rename to #comment in posts, and render controller: :posts, action: :show if #comment.save fails from CommentsController#create
I have figured out the answer myself with the help of others here.
The reason is that I messed up with the JSON format and html format (typical noobie error)
To be able to display the errors using the code I need to change two places ( and change #comment to #new_comment as per #Anthony's advice).
1.
routes.rb:
resources :comments, defaults: { format: 'html' } # I set it as 'json' before
2.
CommentsController.rb:
def create
#new_comment = build_comment(comment_params)
respond_to do |format|
if #new_comment.save
make_child_comment
format.html { redirect_to(:back, :notice => 'Comment was successfully added.') }
else
commentable = commentable_type.constantize.find(commentable_id)
format.html { render template: 'posts/show', locals: {:#post => commentable} }
format.json { render json: #new_comment.errors }
end
end
end

Can't assign tags in Rails 4.2 from model form using acts_as_taggable

I am trying to use the acts_as_taggable_on gem. Everything works in console, I can asoicate tags with a model instance, render the tag_list and link to a results page based on the tag chosen. My issue is that my tags entered into the create form do not save in the db. I have already checked strong_params:
params.require(:contest).permit(:name, :description, :user_id, :show_name, :tag_list => [],...
I had the same problem in a Rails 4.2, ruby 2.2, and acts-as-taggable-on 3.4 app. I changed the params in the controller to update the model. Originally, I had
def update
#post = Post.find(params[:id])
if #post.update(params[:post].permit(:title, :body, :tag_list => []))
redirect_to #post
else
render 'edit'
end
end
I changed the params :tag_list => [] to just :tag_list. It works. My code now looks like the following:
def update
#post = Post.find(params[:id])
if #post.update(params[:post].permit(:title, :body, :tag_list))
redirect_to #post
else
render 'edit'
end
end
def tagged
if params[:tag].present?
#post = Post.tagged_with(params[:tag])
else
#posts = Post.postall
end
end
private
def post_params
params.require(:post).permit(:title, :body, :image, :image2, :tag_list => [])
end
Hope this helps.

Rails 4 *.json.jbuilder files ignored

In my Rails 4.1.1 app (which has the jbuilder gem included), json views always output all columns in the table, ignoring the app/views/[model]/*.json.jbuilder files.
In routes.rb, I have:
resources :workshops do
resources :memberships
resources :events
end
In events_controller.rb, I have:
# GET /workshop/:workshop_id/events
# GET /workshop/:workshop_id/events.json
def index
#events = #workshop.events
respond_to do |format|
format.html
format.json { render json: #events }
end
end
I set the #workshop variable in a "before_action" in the controller.
When I visit /workshops/f00/events, it displays in HTML format as expected.
If I make the file, app/views/events/index.json.jbuilder:
json.events do
end
...when I visit /workshops/f00/events.json, I expect that the output would be empty. However, I get the contents of the entire #events in JSON format.
What I would like to see is only particular fields being output, given a app/views/events/index.json.jbuilder that contains:
json.array!(#events) do |event|
json.extract! event, :id, :title, :description
json.start event.starts_at
json.end event.ends_at
json.url workshop_event_url([#workshop, event], format: :json)
end
... but no matter the contents of the .jbuilder file, the output is always the same. Could anyone tell me why my .jbuilder file is being ignored, and how to get it working?
The line format.json { render json: #events } will always render the #events array since the url /workshops/f00/events accepts both html and json formats and you're rendering #events when hitting the url with the json format.
If you want to render the data in app/views/events/index.json.jbuilder change:
respond_to do |format|
format.html
format.json { render json: #events }
end
to:
respond_to do |format|
format.html
format.json
end
By not rendering the #events array you rely on Rails to output whatever is in app/views/events/index.json.jbuilder.

Best way to use JSON data I retrieved from my Web API, in Rails?

To familiarize myself with Web APIs using Rails I created (2) applications.
POSTS app to create some records and store some data (:name, :title, :content).
CATALOG app to write a Web API to retrieve the data from my POSTS app.
I used the gem HTTParty for my Web API calls. Here is my code from the Catalog App:
new_controller.rb
class NewController < ApplicationController
def index
#response = HTTParty.get("http://localhost:3000/posts.json")
#result = #response.body
respond_to do |format|
format.json { render :json => JSON.parse(#result) }
format.html { render "index.html.erb" }
end
end
end
index.html.erb
<h1>Hello, Rails</h1>
<%= result %>
This successfully POSTed, in my Catalog app, the JSON data for all of my records { :id, :name, :title, :content, edit_url} from my Posts application.
So now I am looking for the best way to take the retrieved JSON data and assign in to self.attributes so that I can use these variables inside my Catalog App.
Could someone provide a nice example of this? Should I use the rabl gem/template inside my catalog app?
Thank You.
One simple option to create "models" from JSON data is to use virtus like:
# app/models/post.rb
class Post
include Virtus.model
attribute :id, Integer
attribute :name, String
attribute :title, String
attribute :content, String
attribute :edit_url, String
def self.from_url(url)
# using collect, assuming that posts.json is an array of posts.
JSON.parse(HTTParty.get(url).body).collect do |item|
new(item['post'])
end
end
end
Then you can use it like:
# controller action
#posts = Post.from_url("http://localhost:3000/posts.json")
respond_to do |format|
format.html { render "index.html.erb" }
end
# view:
<% #posts.each do |post| %>
Name: <%= post.name %><br/>
Rest of the stuff: <%= h post.attributes.inspect %><br/>
<% end %>

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