Updating an item in an array key...

[Travis Bell]

Hey guys,

I swear I read through the docs I could find on this one, and as far as I can tell it's right but I have no idea why it won't save the new values I am trying to dump in:

class Test
   include MongoMapper::Document
   
   key :title, String
   key :_keywords, Array, :index => true
end

test = Test.first(:conditions => {:slug => id})
test._keywords << "test"

test.save

Yet test._keywords is the original value. If I inspect test before I save it, it has the new value in it, but the second I use .save, it reverts back to the original value.

Any ideas?

--

Travis Bell

[Cyril Mougel]

Travis Bell a écrit :

Which version of MongoMapper ?
Maybe it's a dirty issue include in 0.5.x

--
Cyril Mougel
http://blog.shingara.fr/

[Travis Bell]

Hi Cyril,

mongo (0.15.1)

mongo_ext (0.15.1)

mongo_mapper (0.5.5)

--

Travis Bell

[John Nunemaker]

Not sure what your problem is. I'm not having any issues when doing the same thing:

class Test

  include MongoMapper::Document

  key :title, String

  key :_keywords, Array

end

test = Test.new

test._keywords = ['foo', 'bar', 'baz']

test.save

puts Test.find(test.id)._keywords.inspect # ['foo', 'bar', 'baz']

[Travis Bell]

Hey John,

Thanks. The problem seems to be around using before_save:

class Test
   include MongoMapper::Document
   key :title, String
   key :_keywords, Array, :index => true

   before_save do |record|
      record._keywords = record.title.split(' ').uniq
   end
end

Sorry for not including that in my original example. This should not work for you:

class Test
   include MongoMapper::Document
   key :title, String
   key :_keywords, Array, :index => true

   before_save do |record|
      record._keywords = record.title.split(' ').uniq
   end
end

test = Test.create(:title => 'One Two')
test._keywords << "test"
test.save

So I suppose, my question is, what is it about the before_save that is preventing this from working?

--

Travis Bell

[John Nunemaker]

I never use procs like that. I tend to go for a method which can reveal more intent of what you are doing. This works fine for me:

class Test

  include MongoMapper::Document

  key :title, String

  key :_keywords, Array, :index => true

  before_save :set_keywords_from_title

  

  private

    def set_keywords_from_title

      self._keywords = title.split(' ').uniq

    end

end

test = Test.create(:title => 'One Two')

test._keywords << "test"

test.save

puts Test.find(test.id)._keywords.inspect

[Travis Bell]

I copied that code straight up and it does not work. 

Test.find(test.id)._keywords.inspect only contains:

["One", "Two"]

Strange eh?

[John Nunemaker]

That us what it is suppose to contain. Isn't it? An array of keywords from the title? Or did I look at it wrong? 

[Travis Bell]

Yes, but we're updating it with:

test._keywords << "test"

Aren't we?

Shouldn't it contain:

["One", "Two", "test"]

Or maybe it is me who is now confused… *blink-blink*

[Roy Wright]

The problem is that the before_save is overwriting :_keywords.  What you probably want is:

def set_keywords_from_title

  if self._keywords.nil? || self.keywords.empty?

    self._keywords = title.split(' ').uniq

  end

end

HTH,

Roy

[Roy Wright]

Sorry for following up my own post, but have a question regarding the callback I gave.  Does MM follow AR's standard where a return value of false will break the callback chain?  I.e., should the example callback be:

def set_keywords_from_title

  if self._keywords.nil? || self.keywords.empty?

    self._keywords = title.split(' ').uniq

  end

  true

end

TIA,

Roy

[Travis Bell]

Damnit Roy.

Now that you mention it, that makes a whole lot of sense but damn, I didn't even come close to seeing it. Looking in the complete wrong area.

I owe you a beer.

Cheers man,

[Roy Wright]

No problem.  Thank you for themoviedb.org which feeds my gentoo xbmc htpc.  ;)

Have fun,

Roy

[John Nunemaker]

You don't have to return true. I think if you return false though it will stop the callbacks. Don't remember and too lazy to look. :) Will be switching to ActiveModel soon anyway. :)