[RUBY] [Form_with] Let's unify form with form_with.

【goal】

Understand form_with

【merit】

■ Rails recommendation is "form_with" ■ It's not that difficult, so you should remember

【Development environment】

■ Mac OS catalina ■ Ruby on Rails (5.2.4.2) ■ Virtual Box:6.1 ■ Vagrant: 2.2.7

【the difference】

■form_for There is a model. Used for data you want to save in DB

■form_tag No model Used when performing POST processing

■form_with Both swords A convenient method that combines the above two functions

[I actually used it]

When there is a model

• For example, the following models

Model name: Book Column name ①: name Column name ②: title

books/index.html.erb

<% form_with model:Book do |f| %> #model postscript
  <%= f.text_field :name %>
  <%= f.text_area :text %>
  <%= f.submit %>
<% end %>

When there is no model

• Since there is no model, only the information is passed to the specified path [POST method]

hoge.html.erb

<%= form_with url:hoge_path do |f| %>　#Add path name
  <%= f.text_area :name %>
  <%= f.text_area :question %>
  <%= f.submit %>
<% end %>

that's all.

** If there is a model, specify the model name If there is no model, specify by path name **

I also escaped from using it It was really easy, so please use it if you like.