Rails-如何在文本字段中执行If和else语句

Question

我正在尝试在这个文本字段中执行if and else语句，其值为：

<%= f.text_field :rating, :size => 1, :min => 1, :max => 6, :value => if vind.ratings == 0 else vind.rating_score/vind.ratings, :type => 'range', :step => '1', :id => "#{vind.id}" %>

我看到这个错误：

SyntaxError in Kategoris#show
Showing C:/Rails/konkurranceportalen/app/views/kategoris/_rating.html.erb where line #3 raised:
C:/Rails/konkurranceportalen/app/views/kategoris/_rating.html.erb:3: syntax error, unexpected keyword_else, expecting keyword_then or ';' or 'n'
...ue => if vind.ratings == 0 else vind.rating_score/vind.ratin...
...                               ^
C:/Rails/konkurranceportalen/app/views/kategoris/_rating.html.erb:3: syntax error, unexpected ',', expecting ')'
...vind.rating_score/vind.ratings, :type => 'range', :step => '...
...                               ^

Answer 1

我通常使用缩写，如下所示：

:value => ( vind.ratings == 0 ? 0 : vind.rating_score/vind.ratings )

Answer 2

<%= f.text_field :rating, :size => 1, :min => 1, :max => 6, :value => (vind.ratings == 0) ? 0 : vind.rating_score/vind.ratings, :type => 'range', :step => '1', :id => "#{vind.id}" %>

它最终看起来像这样：value。

 :value => (vind.ratings == 0) ? 0 : vind.rating_score/vind.ratings

Answer 3

我可以这样做：

<%= f.text_field :rating, :size => 1, :min => 1, :max => 6, :value => "#{if vind.ratings == 0 else vind.rating_score/vind.ratings, :type => 'range', :step => '1', :id => "#{vind.id}" %>

或类似于上面，但在((中：

<%= f.text_field :rating, :size => 1, :min => 1, :max => 6, :value => ((vind.ratings == 0) ? value_here : vind.rating_score/vind.ratings), :type => 'range', :step => '1', :id => "#{vind.id}" %>