Question

Thanks in advance for any help you can provide!

For my Ruby on Rails website (1.8.7, 2.3.15) I’m trying to pull data from a MySQL table, but I’m running into an “Undefined Method” error. My goal with this code is to display a text list of all locations that fall within a certain latitude and longitudinal range.

Production.log:

ActionView::TemplateError (undefined method `each' for nil:NilClass) on line #31 of     app/views/its/map.html.erb:
28: <!-- TestingLocations -->
29: 
30: <ul id="locations">
31: <% for masterlocation in @nearbylocations %>
32:     <li><%= masterlocation.nickname %></a></li>
33: <% end %>
34: </ul>

Map controller:

def map
@its = Its.find(params[:id])
if @its.user_id == current_user.id
@locations = Location.find(:all, :conditions => ["its_id = ?", params[:id]], :order => "order_num asc")
@mapscount = Saved.count(:all, :conditions => ['its_id = ?', params[:id]])
#@date_filter = Date.civil(params[:date_filter].values_at(:year, :month, :day))
#    debugger
respond_to do |format|
format.html # map.html.erb
format.xml  { render :xml => @its }
end
else
redirect_to '/'

@nearbylocations = Masterlocation.find(:all, :conditions => ["latitude > 25 AND latitude < 30 AND longitude > -75 AND longitude < -70", params[:id]], :order => ['nickname asc'])
end

Again, I appreciate your help!

Answer 1

This happens because @nearbylocations is nil where as it is expecting an Array

you can avoid this by using

<% for masterlocation in @nearbylocations %>
  <li><%= masterlocation.nickname %></a></li>
<% end if @nearbylocations %>

I also notice that you are declared instance variable after redirecting.
Ideally

redirect_to '/'
@nearbylocations = Masterlocation.find(:all, :conditions => ["latitude > 25 AND latitude < 30 AND longitude > -75 AND longitude < -70", params[:id]], :order => ['nickname asc'])

should be

@nearbylocations = Masterlocation.find(:all, :conditions => ["latitude > 25 AND latitude < 30 AND longitude > -75 AND longitude < -70", params[:id]], :order => ['nickname asc'])
redirect_to '/'

But after redirection you can’t use @nearbylocations so you have to use either render or declare it in redirected method.