[GO] How to reflect validation error and input contents on the previous page without using render in the action

Introduction

If you get stuck in validation when submitting form content Render the new post screen with the render method There should be many people who learned by displaying the error or the content that was entered.

But what if you can't use the render method? Actually, I'm using the Google Map API for my portfolio. When rendering a page with render, there is a problem that MAP is not displayed for some reason ...

It was a problem that could be solved by changing the specifications, but I didn't want to change it. I will show you how to achieve the above movement without using render.

Normally when using render

As an example in tasks_controller.rb The action new on the new post page and Suppose you have an action create that saves new posts.

tasks_controller.rb

def create
  @task = Task.new(task_params)
  if @task.save
    redirect_to @task, notice: 'You have saved the task.'
  else
    render :new
  end
end

@ task.save fails and render: new under ʻelseis executed, The new post page will be rendered. After that, as you already know, it feels like using@ task.errors.full_messages` in the view.

When not using render

It takes the form of re-accessing with redirect_to Error statements and input contents are stored in flash in the action.

tasks_controller.rb

def create
  @task = Task.new(task_params)
  if @task.save
    redirect_to @task, notice: 'You have saved the task.'
  else
    flash[:error_msgs] = @task.errors.full_messages
    flash[:tmp_body] = @task.body
    redirect_to new_task_url
  end
end

An error statement in flash [: error_msgs] The text contents are stored in flash [: tmp_body].

After that, it is OK if you use the value of flash in the access destination view. that's all!