The rails-video-review-deep-dive-into-nested-forms from orchardtree

rails-video-review-deep-dive-into-nested-forms's Introduction

Deep Dive into Nested Forms- Overview

In this video lecture, we take a detailed tour through the process of building nested forms: building the form itself using HTML and Rails helper methods, structuring our params hash in a way that makes sense, and ensuring that there are writer methods on our models that receive the data from the params hash—via the controller—and instantiate objects with that data

Objectives

Describe forms, params, and writer methods as a game of catch
Use form_for to have Rails generate HTML for us
Understand what an ActionView::Helpers::FormBuilder object is and what it “knows” about
Call #local_methods on a FormBuilder object to see all of the methods that are available to it
Understand that every key in the params hash should correspond to a writer method
Know what functionality we get for “free” from our association macros, and what functionality we will need to build out ourselves (with custom writers)
Recognize that the convention is #something_attributes= because there will already be a writer method for #something=, and we don’t want to overwrite that
Practice building forms in HTML before using the Rails helpers, so that you can be really specific about what exactly you are creating
Understand that the accepts_nested_attributes_for macro also generates a custom writer, but is much less extensible than building that custom writer yourself
Instantiate objects in the controller so that fields_for inputs will show up in the view
Set attributes on objects instantiated in the controller so that the form can introspect on those objects’ attributes and dynamically set labels