Additional methods in models - how to access them?

rubyonrails-talk
1

Hi!

I'm new in Rails and I'm making my first site using this. I have some problem with methods in models:

I have model Note with one additional method:

class Note < ActiveRecord::Base   belongs_to :pattern   def get_location(location)     find(:conditions => ["location = ?", location])   end end

And when I'm trying to access it through pattern.notes.get_location(1) , it throws an error:

undefined method `get_location' for #<Class:0xb6bc63ec>

What i'm doing wrong?

cheers! Szymon

2

Hi!

I'm new in Rails and I'm making my first site using this. I have some problem with methods in models:

I have model Note with one additional method:

class Note < ActiveRecord::Base belongs_to :pattern def get_location(location) find(:conditions => ["location = ?", location]) end end

And when I'm trying to access it through pattern.notes.get_location(1) , it throws an error:

undefined method `get_location' for #<Class:0xb6bc63ec>

get_location is an instance method of Note but you're trying to call it on a collection of notes (Because associations are also scopes you can call class methods on them: this just calls the class method with finds etc scoped appropriately, but I'm not sure if that is what you were trying to do).

Fred

Fred

3

I'm trying to get Note from this Pattern (which has many notes) with location = 1 for example, how I can do it in rails?

simon

4

But even if I call "Note.get_location(1)", it throws the same error :confused: What i'm doing wrong?

simon

5

But even if I call "Note.get_location(1)", it throws the same error :confused:

As Frederick says, this is an instance method, you're trying to call it on the class. You should do something like @pattern.notes.first.get_location

I highly recommend you to take a look at the rails guides.

6

This works:

pattern.notes.first(:conditions => {:location => location})

But I want use it in views, pattern.notes.get_location(location) looks much better, but how can I make it works?

cheers! simon

7

This works:

pattern.notes.first(:conditions => {:location => location})

But I want use it in views, pattern.notes.get_location(location) looks much better, but how can I make it works?

I am not sure what you are trying to do. Are you trying to find all the notes for that pattern where the location is a specified value? If so you could use Note.find with a condition that note.pattern is the one you want and location is the location you want. In fact I think you should be able to use something like Note.find_all_by_pattern_id_and_location( pattern.id, location )

Alternatively pattern.notes.select{ |n| n.location == required_location } or something similar. If you like this I would make it a method of Pattern so that you can say something like pattern.notes_for_location( required_location )

As an earlier poster suggested, have a look at the rails guides,

By the way it is preferred here to insert replies into the previous post at the appropriate point rather than top posting. It makes it easier to follow the thread. Thanks

Colin

8

class Note < ActiveRecord::Base   belongs_to :pattern   def get_location(location)     find(:conditions => ["location = ?", location])   end end

Should be:

class Note < ActiveRecord::Base   belongs_to :pattern   def self.get_location(location)     find(:conditions => ["location = ?", location])   end end

9

But if you are just doing find(:conditions => ["location = ?", location]) there is already a method defined called find_by_location()

example: Note.find_by_location(location)

10

Wow, I didn't know that there are find_by_property methods already defined, ruby and rails are just great! :slight_smile: I'm switching now from Kohana in PHP to Ruby on Rails, and I can say now, that ruby and rails are much better :slight_smile: Thanks again!

Simon