Code Master Blog: Glimmer DSL for SWT Refined Table

A recent blog post mentioned that in Glimmer DSL for SWT you can data-bind a table bidirectionally in a single line of declarative code, and that this same single line of code does more now by also data-binding extra cell properties by convention in addition to their text content, such as background color, foreground color, font, and image.

Well, in the latest release of Glimmer DSL for SWT, that single line of code is ever shorter now!

So, instead of entering the following to do the table data-binding:

items <=> [@presenter, :contacts, column_attributes: [:first_name, :last_name, :email]]

You can now just enter the following:

items <=> [@presenter, :contacts]

That does the same work now thanks to Convention Over Configuration. Basically, the data-binding statement will figure out the table column model attribute names automatically by convention from the table column names. That is done by assuming underscored versions of them, so for example, for column names 'First Name', 'Last Name', and 'Email', the assumed model attributes are `first_name`, `last_name`, and `email`. This idea originated in Glimmer DSL for LibUI (the CRuby equivalent of Glimmer DSL for SWT) before it got ported to Glimmer DSL for SWT.

To give you more context, including the code of the specified table column names, here is the full editable table declaration in the Glimmer GUI DSL:

table(:editable, :border) {

table_column {

text 'First Name'

width 80

}

table_column {

text 'Last Name'

width 80

}

table_column {

text 'Email'

width 200

}

items <=> [@presenter, :contacts]

}

Additionally, you can now customize attribute names only for columns that diverge from model attributes by supplying a mapping hash (instead of specifying all column attributes in an array). For example, if the `table_column` `text` is 'Email Address' instead of `Email`, then the table items (rows) data-binding declaration can map that column to the `email` model attribute, but leave the rest of the model attributes normally derived from column names by convention (e.g. `first_name` and `last_name`):

items <=> [@presenter, :contacts, column_attributes: {'Email Address' => :email}]

In other big news, Glimmer DSL for SWT 4.24.4.0 now ships with a brand new custom widget called `refined_table`, which enables displaying very large amounts of data by applying pagination, thus providing a more user-friendly experience for bigger tables (filtering support is coming in the future). Also, table data-binding performance has been optimized.

The idea for this custom widget originated in Glimmer DSL for LibUI (the CRuby equivalent of Glimmer DSL for SWT), and was recently blogged about, including its use in Rubio-Radio.

However, there are differences in the functionality and syntax of `refined_table` in Glimmer DSL for SWT. The page count is displayed in the same text field that displays the page number. When typing inside the text field, only the page number is needed, but it does not update the table until hitting ENTER or tabbing off / losing focus. Also, it was designed to be intentionally a drop-in replacement for `table`, so its syntax is as close as possible to that of `table`. That means, you simply use the keyword `refined_table` instead of `table`, but then continue to declare `table_column`s within it, and then you perform a data-binding, but on the `model_array` custom property instead of `items` to provide the complete master model collection and leave `refined_table` to do its own data-binding of `items` from the paginated collection of models instead of the master collection.

Hello, Refined Table! Code:

	require 'glimmer-dsl-swt'
	require 'date'

	class HelloRefinedTable
	BaseballTeam = Struct.new(:name, :town, :ballpark, keyword_init: true) do
	class << self
	def all
	@all \|\|= [
	{town: 'Chicago', name: 'White Sox', ballpark: 'Guaranteed Rate Field'},
	{town: 'Cleveland', name: 'Indians', ballpark: 'Progressive Field'},
	{town: 'Detroit', name: 'Tigers', ballpark: 'Comerica Park'},
	{town: 'Kansas City', name: 'Royals', ballpark: 'Kauffman Stadium'},
	{town: 'Minnesota', name: 'Twins', ballpark: 'Target Field'},
	{town: 'Baltimore', name: 'Orioles', ballpark: 'Oriole Park at Camden Yards'},
	{town: 'Boston', name: 'Red Sox', ballpark: 'Fenway Park'},
	{town: 'New York', name: 'Yankees', ballpark: 'Comerica Park'},
	{town: 'Tampa Bay', name: 'Rays', ballpark: 'Tropicana Field'},
	{town: 'Toronto', name: 'Blue Jays', ballpark: 'Rogers Centre'},
	{town: 'Houston', name: 'Astros', ballpark: 'Minute Maid Park'},
	{town: 'Los Angeles', name: 'Angels', ballpark: 'Angel Stadium'},
	{town: 'Oakland', name: 'Athletics', ballpark: 'RingCentral Coliseum'},
	{town: 'Seattle', name: 'Mariners', ballpark: 'T-Mobile Park'},
	{town: 'Texas', name: 'Rangers', ballpark: 'Globe Life Field'},
	{town: 'Chicago', name: 'Cubs', ballpark: 'Wrigley Field'},
	{town: 'Cincinnati', name: 'Reds', ballpark: 'Great American Ball Park'},
	{town: 'Milwaukee', name: 'Brewers', ballpark: 'American Family Field'},
	{town: 'Pittsburgh', name: 'Pirates', ballpark: 'PNC Park'},
	{town: 'St. Louis', name: 'Cardinals', ballpark: 'Busch Stadium'},
	{town: 'Atlanta', name: 'Braves', ballpark: 'Truist Park'},
	{town: 'Miami', name: 'Marlins', ballpark: 'LoanDepot Park'},
	{town: 'New York', name: 'Mets', ballpark: 'Citi Field'},
	{town: 'Philadelphia', name: 'Phillies', ballpark: 'Citizens Bank Park'},
	{town: 'Washington', name: 'Nationals', ballpark: 'Nationals Park'},
	{town: 'Arizona', name: 'Diamondbacks', ballpark: 'Chase Field'},
	{town: 'Colorado', name: 'Rockies', ballpark: 'Coors Field'},
	{town: 'Los Angeles', name: 'Dodgers', ballpark: 'Dodger Stadium'},
	{town: 'San Diego', name: 'Padres', ballpark: 'Petco Park'},
	{town: 'San Francisco', name: 'Giants', ballpark: 'Oracle Park'},
	].map {\|team_kwargs\| new(team_kwargs)}
	end
	end

	def complete_name
	"#{town} #{name}"
	end
	end

	BaseballGame = Struct.new(:date, :home_team, :away_team, keyword_init: true) do
	def home_team_name
	home_team.complete_name
	end

	def away_team_name
	away_team.complete_name
	end

	def ballpark
	home_team.ballpark
	end
	end

	BaseballSeason = Struct.new(:year) do
	def games
	if @games.nil?
	@games = []
	baseball_team_combinations = BaseballTeam.all.combination(2).to_a
	current_day = first_day
	day_offset = 0
	begin
	if (day_offset % 7 != 6)
	day_games = []
	half_teams_count = BaseballTeam.all.count / 2
	while day_games.uniq.count < half_teams_count
	baseball_team_pair = baseball_team_combinations.sample
	teams_played_so_far = day_games.map {\|game\| [game.home_team, game.away_team]}.flatten
	unless teams_played_so_far.include?(baseball_team_pair.first) \|\| teams_played_so_far.include?(baseball_team_pair.last)
	baseball_game = BaseballGame.new(
	date: current_day,
	home_team: baseball_team_pair.first,
	away_team: baseball_team_pair.last,
	)
	day_games << baseball_game
	@games << baseball_game
	end
	end
	end
	day_offset += 1
	current_day += 1
	end while current_day != first_day_of_playoffs
	end
	@games
	end

	def first_day
	@first_day \|\|= Date.new(year, 04, 01)
	end

	def first_day_of_playoffs
	@last_day \|\|= Date.new(year, 10, 01)
	end
	end

	include Glimmer::UI::Application

	before_body do
	@baseball_season = BaseballSeason.new(Time.now.year)
	end

	body {
	shell {
	text 'Hello, Refined Table!'

	refined_table(per_page: 20) { # also `page: 1` by default
	table_column {
	width 100
	text 'Date'
	}
	table_column {
	width 200
	text 'Ballpark'
	}
	table_column {
	width 150
	text 'Home Team'
	}
	table_column {
	width 150
	text 'Away Team'
	}

	model_array <= [@baseball_season, :games, column_attributes: {'Home Team' => :home_team_name, 'Away Team' => :away_team_name}]
	}
	}
	}

	end

	HelloRefinedTable.launch