Skip to main content

How does Rails scaffolding select HTML input tags?

Recently, a reader saw my fix for SQL Server booleans, and asked me a followup question: why does Rails display a yes/no selection instead of a checkbox? The short answer is look in {RUBY_HOME} /lib/ruby/gems/1.8 /gems/actionpack-1.10.2 /lib/action_view/helpers, but your path may vary depending on whether you are using gem, "edge rails", etc. Anyway, look in the file "active_record_helper.rb" for a method called "all_input_tags", and notice that it calls "default_input_block" if you don't supply an input_block. Now notice that "default_input_block" creates a label and calls "input(record, column.name)" which in turn calls "InstanceTag#to_tag" which finally looks at the datatype and maps boolean to a select tag. Perhaps a wiser Rails explorer can provide us with the rationale for this, but I guess we could add a MixIn for InstanceTag that redefines the to_tag() method, or just do a dirty and unmaintainable hack like changing to_boolean_select_tag(options) to to_check_box_tag(options).

I would advise that you research mixins, or just generate your view and change the select to a checkbox. I'm in a bit of a time crunch at work today, but this will at least get you started.

Comments

لورن said…
I just ran across this myself and after some hunting around, I found your entry about it. I also wonder why a select widget is used instead of a checkbox widget. Did you ever find out?
January 12, 2006 7:33 PM
Anonymous said…
Blank checkbox values aren't submitted with the form, so with a checkbox there isn't an easy way to indicate a value updated from true to false exists. Rails normally gets around this checkbox issue by including a hidden field with the same name after each checkbox (the empty value then 'stands in' for blank checkboxes). This is a bit of a hack, which is probably why scaffolding avoids it.
January 05, 2009 7:05 PM
Post a Comment

Popular posts from this blog

Castle ActiveRecord with DetachedCriteria

My current development environment is Visual Studio Express C# Edition (read that as free ), Castle ActiveRecord's latest svn trunk(usually within a few days), and NHibernate svn trunk. As of NHibernate version 1.2.0, there is a very cool new class out there ... DetachedCriteria. This class lets you set all of your Castle relational attributes like BelongsTo, HasMany, etc. as lazy fetch, and over-ride this for searches, reports, or anytime you know ahead of time that you will be touching the related classes by calling detachedCriteria.SetFetchMode(..., FetchEnum.Eager). As a good netizen, I have tried to contribute to NHibernate and Castle ActiveRecord even if only in the smallest of ways . Oh yeah, I tried mapping to a SQL VIEW, and it worked GREAT! I received a comment after my last post, indicating that there is a better way, and I am sure of it, but the view guaranteed that I only have one database request for my dataset. NHibernate was wanting to re-fetch my missing as...
1 comment
Read more

Destiny 2 - The Corrupted Nightfall

 == Overview == This Dreaming City Nightfall is already considered one of the most irritating strikes, in part because of bugs that sometimes prevent players from proceeding to the next encounter.  Notable bugged areas are the transition from the Elevator to the Knights Steps, and after the passage, the temple sometimes doesn't reveal a way to the shadow realm where you will take your leap. Important Note: After a "de-buff" from Particle Deconstruction, shoot the boss in the head!  It is quite effective, and can melt her with some coordination. Champions: Unstoppable and Overload Shields: Arc, Solar and Void (many shields!) Don't place your well in the open where boss can snipe the sword!  She will break your super. Pass the "Relic" (Orb) twice to maximize damage. == Loadouts == General: * Add Taken spec to every weapon Titans: * Bottom Tree Solar + Path of the Burning Steps or Phoenix Cradle * Sentinal Shield + Ursa, Aeon Gauntlets Warlocks: * Stasis + Blea...
Post a Comment
Read more