Ruby-on-rails Rails if 语句语法
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Rails if statement syntax
提问by cjm2671
I've written the following ERB and am getting a syntax error at the question mark. This helper function from devise currently evaluates as false. What have I missed?
我编写了以下 ERB，但在问号处出现语法错误。来自设计的这个辅助函数当前评估为假。我错过了什么？
<%= if user_signed_in? %>
<%= render 'form' %>
<%= end %>
回答by SteenhouwerD
Try this :
尝试这个 ：
<% if user_signed_in? %>
<%= render 'form' %>
<% end %>
If you do <%= ... %>, it will try to output the thing you put between the tags. But, if you do <% ... %>, then no output is processed, just the code is evaluated. If this is not working, then there is probably something wrong with your user_signed_in? helper method.
如果你做 <%= ... %>，它会尝试输出你放在标签之间的东西。但是，如果您执行 <% ... %>，则不会处理任何输出，只会评估代码。如果这不起作用，那么您的 user_signed_in 可能有问题？辅助方法。
回答by Mario Uher
<%=will try to output your user_signed_in?helper, so try:
<%=将尝试输出您的user_signed_in?助手，因此请尝试：
<% if user_signed_in? %>
<%= render 'form' %>
<% end %>
or even better (and less confusing):
甚至更好（并且不那么令人困惑）：
<%= render 'form' if user_signed_in? %>
回答by Mahesh
try this
尝试这个
<% if user_signed_in? %>
<%= render 'form' %>
<% end %>
