how to pass value of a variable from javascript to rails

Question

I am pretty new to rails, please help me out.

This is my javascript i want filename value to be passed in the controller page_controller to the create_table action

$(document).ready(function(){
$("#prefix, #client, #myFile").change(function(){
    concatenated_string = $("#prefix").val() + "_" + $("#client").val() + "_" + $("#myFile").val();
    $("#concatenated_string").val(concatenated_string);
     myvar = concatenated_string.replace(/C:\\fakepath\\/i, '');
     myvar = myvar.replace(/\..+$/, '');
     myvar = myvar.replace(/\s+/, "_");

     var filename = myvar //This variable

    $("#temp_display").text(filename)

 })
})

This below file is my page_controller.rb and the create_table action

class PageController < ApplicationController

  # before_action :authenticate_user!
  #before_action :set_company, only: [:show, :edit, :update, :destroy]
  before_action :authenticate_user!, only: [:index]

  def home
  end


  def titlebar
  end


 def insert_table
  #redirect_to :action => "create_table"
 end 

  def create_table

            filename = params[:filename]

  end  
end

This is what am getting in terminal

    Started POST "/page/create_table" for ::1 at 2017-01-28 20:45:05 +0530
Processing by PageController#create_table as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"TAcnZfhr8Amg8/xupgJVlAosz+/hNPgFgxVT4cg5x+OKvRwvrtm6Z5momvQiHsYBcl1tZWUu525Z1VTxqWIu8Q==", "commit"=>"upload file"}
  Rendering page/create_table.html.erb within layouts/application
  Rendered page/create_table.html.erb within layouts/application (0.5ms)
Completed 200 OK in 190ms (Views: 186.7ms | ActiveRecord: 0.0ms)

Answer 1

You can have a hidden input field in the form like below for which the filename value can be appended, so that you can capture the value in the create_table action.

#in your form
<input type="hidden" name="filename" id="my_file_name" value="">

And in script

$(document).ready(function(){
$("#prefix, #client, #myFile").change(function(){
    concatenated_string = $("#prefix").val() + "_" + $("#client").val() + "_" + $("#myFile").val();
    $("#concatenated_string").val(concatenated_string);
     myvar = concatenated_string.replace(/C:\\fakepath\\/i, '');
     myvar = myvar.replace(/\..+$/, '');
     myvar = myvar.replace(/\s+/, "_");

     var filename = myvar //This variable

    $("#temp_display").text(filename);
    $("#my_file_name").val() = filename; //Add this line

 })
})

Now, you can capture the value of filename with params[:filename] .

Answer 2

I got the solution .

this is my js

function myFunction()
{
    concatenated_string = $("#prefix").val() + "_" + $("#client").val()     + "_" + $("#myFile").val();
 $("#concatenated_string").val(concatenated_string);
 myvar = concatenated_string.replace(/C:\\fakepath\\/i, '');
 myvar = myvar.replace(/\..+$/, '');
 myvar = myvar.replace(/\s+/, "_");

 var filename = myvar;

$("#temp_display").text(filename);
document.getElementById("my_file_name").value = filename;  
}

this is in my view as suggested by pavan

<input type="hidden" name="filename" id="my_file_name" value="">

this is my controller

  def create_table
        filename = params[:filename]
        content = params[:file].path
  end