rails 3.0.3 check if boolean value is true

Question

I want to check if a value is true or false.

<% if item.active? %>
    <%= image_tag('on.png', :alt => "Active", :border => 0) %>
<% else %> 
    <%= image_tag('off.png', :alt => "Inactive", :border => 0) %>
<% end %>

That doesn't work, but this works?

<% if item.active == true %>
    <%= image_tag('on.png', :alt => "Active", :border => 0) %>
<% else %> 
    <%= image_tag('off.png', :alt => "Inactive", :border => 0) %>
<% end %>

Shouldn't the first method work or am I missing something?

I know you already have accepted an answer, but I wonder, what do you mean by "does not work"? Also, remember that 'true' in ruby means "everything (!) except false and nil". For example 0, "0", empty array and so on, all represent truth. Maybe that was the problem? — Arsen7
– Arsen7, Commented Nov 25, 2010 at 13:13

nonopolarity · Accepted Answer · 2010-11-25 09:57:55Z

66

if this line works:

if item.active == true

then

if item.active

will also work. if item.active? works only if there is a method whose name is actually active?, which is usually the convention for naming a method that returns true or false.

answered Nov 25, 2010 at 9:57

nonopolarity

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1 Comment

Max Williams Over a year ago

Just as an aside, rails adds in the <attribute>? method for boolean fields. This will return false if the value is set to false (ie 0/f/whatever) or nil. So, if you have an active attribute that is based on a boolean database field, then .active? should work. Generally though, it's better to just say "if item.active" as 動靜能量 suggests.

rwilliams · Accepted Answer · 2010-11-25 10:00:19Z

2

This should work for you assuming item.active is truly a boolean value. Unless there is a method defined for item.active? your example will only return a no-method error.

<% if item.active %>
    <%= image_tag('on.png', :alt => "Active", :border => 0) %>
<% else %> 
    <%= image_tag('off.png', :alt => "Inactive", :border => 0) %>
<% end %>

answered Nov 25, 2010 at 10:00

rwilliams

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Comments

gsumk · Accepted Answer · 2019-08-28 14:57:05Z

0

The other way is using single line if else

<%= active ? here is your statement for true : here is your statement for false %>

For active? to work there should be an def active? method in your item object.

edited Aug 28, 2019 at 14:57

answered Aug 20, 2019 at 20:56

gsumk

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