Check for save after update Rails 4 - ruby-on-rails

Question

An update method for one of my controllers looks like this:
def update
#node = Node.find(params[:id])
#video = #node.media
#node.update(node_params)
#video.update(title: #node.name, description: #node.description)
end
I need a callback to make sure that the #node and #video updated. What's the best way to do this?

Answer 1

You can test if the update succeeds...
if #node.update(node_params)
# handle success
if #video.update(title: #node.name, description: #node.description)
# etc...
end
else
# handle fail
end
In an ajax request, you can put the condition in the view:
<% if #node.errors.any? %>
alert('<%= j(#node.errors.full_messages.join("\n")) %>');
<% else %>
alert('Success')
<% end %>

Answer 2

Based on what you said, I think this is what you might want
def update
#node = Node.find(params[:id])
#video = #node.media
#node_saved = true
#video_saved = true
begin
#node.update_attirbutes!(node_params)
rescue ActiveRecord::RecordInvalid
#node_saved = false
end
begin
#video.update_attributes!(title: #node.name, description: #node.description)
rescue ActiveRecord::RecordInvalid
#video_saved = false
end
render "mypage"
end
Inside your update.js.erb
...
if (<%= #node_saved %> === false) {
// trigger flash message
};
if (<%= #video_saved %> === false) {
// trigger flash message
};
I may still be misunderstanding what you want, but this or #Swards answer should answer your question.

Answer 3

Rails' .save and .update return true/false (boolean) depending on whether the action was successful.
The standard way of utilizing that in your flow is as follows:
def update
#node = Node.find params[:id]
respond_to do |format|
if #node.update(node_params)
format.js #-> invokes /views/nodes/update.js.erb
format.json { render json: #node.to_json }
format.html
else
format.js #-> invokes /views/nodes/update.js.erb
format.json
format.html
end
end
end
You shouldn't be using the #video.update using the exact same data as #node - you can do that in the model. You'll be best using associations etc, which I can explain if required.
#app/models/node.rb
class Node < ActiveRecord::Base
belongs_to :media #?
before_save :set_media, on: :update
private
def set_media
self.media.name = self.name
self.media.description = self.description
end
end
Ajax
My front-end UI developer has some jQuery that I need a callback for
Since I don't know the spec for this, I cannot give you any specific code.
What I can tell you is that if you're using ajax, you have to make sure you understand the difference between server-side & client-side code.
I don't want to insult your intelligence but I'll explain it for posterity's sake...
Frontend ajax will look like this:
#app/assets/javascripts/application.js
$(document).on("click", ".element", function(){
$.ajax({
url: "...",
data: ....,
success: function(data) { },
error: function(response) {}
});
});
... since this is client side code, you can only deal with data returned from the server. A common misunderstanding is many people thinking they'll somehow be able to use Ruby code/methods in this. No.
You can only send back pre-packaged data to this, so if you wanted your data to be condition, you'd do something like this:
def update
#node = Node.find params[:id]
#returned = "yes" if #node.update(node_params)
render [x], layout: !request.xhr?
end
This will allow you to send back conditional data, with which you'll be able to use the front-end JS to manipulate:
$.ajax({
...
success: function(data) {
... do something with data
}
--
If you wanted to use server side code, you'll be better using the inbuilt format.js functionality:
def update
#node = Node.find params[:id]
respond_to do |format|
format.js #-> app/views/nodes/update.js.erb
end
end
This does allow you to use Ruby code, as the JS is rendered server-side, and passed to the browser. I'm not sure as to the specifics, but I know you can do the following with it:
#app/views/nodes/update.js.erb
<% if #node.something %>
$("js")....
<% else %>
...
<% end %>