Krzysztof Piotrowski RoR developer 2nIT www.2n.pl

Trailblazer 2.1 Cells - Lighting Talk

Content: ● Cells purpose ● Cells itselfs ● Some code example ● Summary

Cells purpose Cells purpose ● Removing business (and other) logic from views ● Code readability goes up by a mile ● Following OOP/SOLID/SRR/etc. ● No more partials and helpers using global state of the app. ● Cells want to segregate your UI into logical fragments ● Rendering a template anywhere you want with eaze ● Providing a logical and clean files structure and architecture

Cell https://github.com/trailblazer/cells - View Object à la Controller - Does not have to be coupled with TB - It can render html anywhere (good to be used with emails as well as classic app views) - Not Rails dependent - Layout change with eaze (so controller doesn’t care about it since it is not his responsibility) - Cells will encourage and reward you for building the code for view in a way that provides the application with encapsulated UI fragments having access to only stuff they actually need to render a part of UI/view

Object that renders a template

No content

proposals_controlller.rb && index.html.haml

event_row.rb

event_row.haml

Proposal::Cell::Index.new(user, current_user: other_user, layout: Cfp::Cell::BaseLayout)

● Formats for views you can work on using cells: haml, hamlit, erb, slim ● Cells can handle not only Active Records objects passed to it - they are fine handling basically anything you want. ● Context withinh a cell rendered from controller contains its data by default and passes it further ● You can also generate form inputs via Cells ● You can redefine #show method and pass arguments Few other hints / informations

● Summary <

Be careful!