Re: [Rails] has_many_through new association for exisitng records

[Walter Lee Davis]

> On Feb 9, 2018, at 5:01 PM, fugee ohu  wrote:
> 
> 
> 
> On Thursday, February 8, 2018 at 12:23:43 PM UTC-5, Walter Lee Davis wrote:
> That validation was probably on the person, not the picture, unless you added 
> validates_associated to the Person class. 
> 
> Look at this: 
> https://github.com/walterdavis/fugee/blob/master/app/controllers/people_controller.rb#L74
>  
> 
> and this: 
> 
> https://github.com/walterdavis/fugee/blob/master/app/views/people/_form.html.erb#L25
>  
> 
> The rest is scaffolded, there's nothing mysterious here. 
> 
> Clone this to your machine, run it in rails server. 
> 
> Go to localhost:3000/pictures and add some pictures (just file names). 
> 
> Go to localhost:3000/people, and add some people. 
> 
> See how you can choose pictures for each person? See how the association is 
> saved and updated? Watch in the console as the record is saved or updated 
> from the web. 
> 
> Walter 
> 
> > On Feb 8, 2018, at 11:36 AM, fugee ohu  wrote: 
> > 
> > I created an update action in the persons controller Valitadation was 
> > failing with :name can't be blank so I assumed @person.save was trying to 
> > create a new picture That's why I moved the action from the pictures 
> > controller to the persons controller and changed the action to 
> > @person.update instead of @person.save Did you already understand that? 
> 
> Do  I have to create routes like "get '/people/:id/addresses' => 
> 'addresses#index', as: 'person_addresses' I was thinking maybe rails already 
> creates those routes from the associations and if I make them explicit maybe 
> I'll mess up the routes 
> 

Rails would make those if you had nested routes:

resources :people do
  resources :addresses
end

That will require you to do some additional changes in your addresses 
controller -- knowing that you will always have a person_id attribute running 
around in all actions, for example.

Read the relevant Rails guide (routing, I think).

Walter


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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Thursday, February 8, 2018 at 12:23:43 PM UTC-5, Walter Lee Davis wrote:
>
> That validation was probably on the person, not the picture, unless you 
> added validates_associated to the Person class. 
>
> Look at this: 
> https://github.com/walterdavis/fugee/blob/master/app/controllers/people_controller.rb#L74
>  
>
> and this: 
>
>
> https://github.com/walterdavis/fugee/blob/master/app/views/people/_form.html.erb#L25
>  
>
> The rest is scaffolded, there's nothing mysterious here. 
>
> Clone this to your machine, run it in rails server. 
>
> Go to localhost:3000/pictures and add some pictures (just file names). 
>
> Go to localhost:3000/people, and add some people. 
>
> See how you can choose pictures for each person? See how the association 
> is saved and updated? Watch in the console as the record is saved or 
> updated from the web. 
>
> Walter 
>
> > On Feb 8, 2018, at 11:36 AM, fugee ohu  
> wrote: 
> > 
> > I created an update action in the persons controller Valitadation was 
> failing with :name can't be blank so I assumed @person.save was trying to 
> create a new picture That's why I moved the action from the pictures 
> controller to the persons controller and changed the action to 
> @person.update instead of @person.save Did you already understand that? 
>
> Do  I have to create routes like "get '/people/:id/addresses' => 
'addresses#index', as: 'person_addresses' I was thinking maybe rails 
already creates those routes from the associations and if I make them 
explicit maybe I'll mess up the routes 

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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Thursday, February 8, 2018 at 12:23:43 PM UTC-5, Walter Lee Davis wrote:
>
> That validation was probably on the person, not the picture, unless you 
> added validates_associated to the Person class. 
>
> Look at this: 
> https://github.com/walterdavis/fugee/blob/master/app/controllers/people_controller.rb#L74
>  
>
> and this: 
>
>
> https://github.com/walterdavis/fugee/blob/master/app/views/people/_form.html.erb#L25
>  
>
> The rest is scaffolded, there's nothing mysterious here. 
>
> Clone this to your machine, run it in rails server. 
>
> Go to localhost:3000/pictures and add some pictures (just file names). 
>
> Go to localhost:3000/people, and add some people. 
>
> See how you can choose pictures for each person? See how the association 
> is saved and updated? Watch in the console as the record is saved or 
> updated from the web. 
>
> Walter 
>
> > On Feb 8, 2018, at 11:36 AM, fugee ohu  
> wrote: 
> > 
> > I created an update action in the persons controller Valitadation was 
> failing with :name can't be blank so I assumed @person.save was trying to 
> create a new picture That's why I moved the action from the pictures 
> controller to the persons controller and changed the action to 
> @person.update instead of @person.save Did you already understand that? 
>
>
I'll do that today thanks In the meanwhile, the validtion's in picture.rb

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Re: [Rails] has_many_through new association for exisitng records

[Walter Lee Davis]

That validation was probably on the person, not the picture, unless you added 
validates_associated to the Person class.

Look at this: 
https://github.com/walterdavis/fugee/blob/master/app/controllers/people_controller.rb#L74

and this:

https://github.com/walterdavis/fugee/blob/master/app/views/people/_form.html.erb#L25

The rest is scaffolded, there's nothing mysterious here.

Clone this to your machine, run it in rails server.

Go to localhost:3000/pictures and add some pictures (just file names).

Go to localhost:3000/people, and add some people. 

See how you can choose pictures for each person? See how the association is 
saved and updated? Watch in the console as the record is saved or updated from 
the web.

Walter

> On Feb 8, 2018, at 11:36 AM, fugee ohu  wrote:
> 
> I created an update action in the persons controller Valitadation was failing 
> with :name can't be blank so I assumed @person.save was trying to create a 
> new picture That's why I moved the action from the pictures controller to the 
> persons controller and changed the action to @person.update instead of 
> @person.save Did you already understand that?

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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Thursday, February 8, 2018 at 11:36:47 AM UTC-5, fugee ohu wrote:
>
>
>
> On Thursday, February 8, 2018 at 11:10:29 AM UTC-5, Walter Lee Davis wrote:
>>
>>
>> > On Feb 8, 2018, at 8:28 AM, fugee ohu  wrote: 
>> > 
>> > I was having trouble hiding and showing elements on the form so I 
>> created a separate action in the pictures controller to handle the 
>> submission of the form that selects pictures to add to the person from 
>> existing pictures in the database It attempts to create a new picture I 
>> guess because validation fails :name cannot be blank 
>> > 
>> > def add_from_pictures_create 
>> >if (params[:picture][:person_id]) 
>> >@person=Person.find(params[:picture][:person_id]) 
>> >@pictures = Picture.find(params[:person][:picture_ids]) 
>>
>> # these are now new instances -- with different object IDs -- than the 
>> ones you want to compare them with 
>>
>> >@person.pictures << @pictures 
>>
>> # assigning these in this way means that you are adding an array to an 
>> array. Trouble is, you are adding duplicate instances in the second array 
>> to an array which may already contain the ones you want to add. 
>>
>> >respond_to do |format| 
>> >  if @person.save 
>> > format.html {  redirect_to 
>> pictures_path(person_id: params[:picture][:person_id]), notice: 'Person 
>> picture updated.' } 
>> > format.json { render :show, status: 
>> :created, location: @picture } 
>>
>> I would avoid this entire approach. Think about this in the abstract: you 
>> are editing and updating the @person, manipulating the picture_ids 
>> attribute on that instance. Your form is built on the person. This form 
>> should be submitted to the PersonController#update method. If you have (as 
>> I have said many times in this thread) whitelisted the picture_ids 
>> attribute, then simply calling @person.save will persist that attribute -- 
>> it is already going to be in the person_params strong parameters hash. 
>>
>> Here's a clue: when you find yourself writing something like this in a 
>> controller: 
>>
>> > @person=Person.find(params[:picture][:person_id]) 
>>
>> ...just walk away and have a think about your life. 
>>
>> Walter 
>>
>>
> I created an update action in the persons controller Valitadation was 
> failing with :name can't be blank so I assumed @person.save was trying to 
> create a new picture That's why I moved the action from the pictures 
> controller to the persons controller and changed the action to 
> @person.update instead of @person.save Did you already understand that?
>

You wanted me to use patch or post to achieve @person.pictures << @pictures 
and then I would wanna use if @person.save or if @person.update Please 
clarify that Thanks in advance  I took out the stuff left over from when 
this routine was in the pictures controller and now rely on the callback 
set_person 

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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Thursday, February 8, 2018 at 11:10:29 AM UTC-5, Walter Lee Davis wrote:
>
>
> > On Feb 8, 2018, at 8:28 AM, fugee ohu  
> wrote: 
> > 
> > I was having trouble hiding and showing elements on the form so I 
> created a separate action in the pictures controller to handle the 
> submission of the form that selects pictures to add to the person from 
> existing pictures in the database It attempts to create a new picture I 
> guess because validation fails :name cannot be blank 
> > 
> > def add_from_pictures_create 
> >if (params[:picture][:person_id]) 
> >@person=Person.find(params[:picture][:person_id]) 
> >@pictures = Picture.find(params[:person][:picture_ids]) 
>
> # these are now new instances -- with different object IDs -- than the 
> ones you want to compare them with 
>
> >@person.pictures << @pictures 
>
> # assigning these in this way means that you are adding an array to an 
> array. Trouble is, you are adding duplicate instances in the second array 
> to an array which may already contain the ones you want to add. 
>
> >respond_to do |format| 
> >  if @person.save 
> > format.html {  redirect_to 
> pictures_path(person_id: params[:picture][:person_id]), notice: 'Person 
> picture updated.' } 
> > format.json { render :show, status: 
> :created, location: @picture } 
>
> I would avoid this entire approach. Think about this in the abstract: you 
> are editing and updating the @person, manipulating the picture_ids 
> attribute on that instance. Your form is built on the person. This form 
> should be submitted to the PersonController#update method. If you have (as 
> I have said many times in this thread) whitelisted the picture_ids 
> attribute, then simply calling @person.save will persist that attribute -- 
> it is already going to be in the person_params strong parameters hash. 
>
> Here's a clue: when you find yourself writing something like this in a 
> controller: 
>
> > @person=Person.find(params[:picture][:person_id]) 
>
> ...just walk away and have a think about your life. 
>
> Walter 
>
>
I created an update action in the persons controller Valitadation was 
failing with :name can't be blank so I assumed @person.save was trying to 
create a new picture That's why I moved the action from the pictures 
controller to the persons controller and changed the action to 
@person.update instead of @person.save Did you already understand that?

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Re: [Rails] has_many_through new association for exisitng records

[Walter Lee Davis]

> On Feb 8, 2018, at 8:28 AM, fugee ohu  wrote:
> 
> I was having trouble hiding and showing elements on the form so I created a 
> separate action in the pictures controller to handle the submission of the 
> form that selects pictures to add to the person from existing pictures in the 
> database It attempts to create a new picture I guess because validation fails 
> :name cannot be blank
> 
> def add_from_pictures_create
>if (params[:picture][:person_id])
>@person=Person.find(params[:picture][:person_id])
>@pictures = Picture.find(params[:person][:picture_ids])

# these are now new instances -- with different object IDs -- than the ones you 
want to compare them with

>@person.pictures << @pictures

# assigning these in this way means that you are adding an array to an array. 
Trouble is, you are adding duplicate instances in the second array to an array 
which may already contain the ones you want to add.

>respond_to do |format|
>  if @person.save
> format.html {  redirect_to 
> pictures_path(person_id: params[:picture][:person_id]), notice: 'Person 
> picture updated.' }
> format.json { render :show, status: :created, 
> location: @picture } 

I would avoid this entire approach. Think about this in the abstract: you are 
editing and updating the @person, manipulating the picture_ids attribute on 
that instance. Your form is built on the person. This form should be submitted 
to the PersonController#update method. If you have (as I have said many times 
in this thread) whitelisted the picture_ids attribute, then simply calling 
@person.save will persist that attribute -- it is already going to be in the 
person_params strong parameters hash.

Here's a clue: when you find yourself writing something like this in a 
controller:

> @person=Person.find(params[:picture][:person_id])

...just walk away and have a think about your life.

Walter

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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Sunday, February 4, 2018 at 6:25:46 PM UTC-5, Walter Lee Davis wrote:
>
> Even more interesting (to me, anyway) is what happens if you create (but 
> don't save) any of these objects: 
>
> 2.4.2 :006 > p = Person.new name: 'Walter' 
>  => # 
> 2.4.2 :007 > c = Picture.new file: 'some file' 
>  => # nil> 
> 2.4.2 :008 > p.pictures << c 
>  => # file: "some file", created_at: nil, updated_at: nil>]> 
> 2.4.2 :009 > p.save 
>(1.9ms)  begin transaction 
>   SQL (23.1ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 23:23:15.342294"], ["updated_at", "2018-02-04 23:23:15.342294"]] 
>   SQL (0.3ms)  INSERT INTO "pictures" ("file", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["file", "some file"], ["created_at", "2018-02-04 
> 23:23:15.374862"], ["updated_at", "2018-02-04 23:23:15.374862"]] 
>   SQL (0.4ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 2], 
> ["picture_id", 2], ["created_at", "2018-02-04 23:23:15.376805"], 
> ["updated_at", "2018-02-04 23:23:15.376805"]] 
>(1.3ms)  commit transaction 
>  => true 
> 2.4.2 :010 > 
>
> When you save one of them, all three are saved in order to preserve the 
> entire set of relationships. 
>
> Walter 
>
> > On Feb 4, 2018, at 4:54 PM, Walter Lee Davis  > wrote: 
> > 
> > I can't duplicate this finding here. Here's the console log: 
> > 
> > 2.4.2 :001 > p = Person.new name: 'Walter' 
> > => # 
> > 2.4.2 :002 > p.save 
> >   (0.2ms)  begin transaction 
> >  SQL (2.8ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 21:47:31.000973"], ["updated_at", "2018-02-04 21:47:31.000973"]] 
> >   (1.3ms)  commit transaction 
> > => true 
> > 2.4.2 :003 > c = Picture.new file: 'some file' 
> > => # nil> 
> > 2.4.2 :004 > c.save 
> >   (0.2ms)  begin transaction 
> >  SQL (2.2ms)  INSERT INTO "pictures" ("file", "created_at", 
> "updated_at") VALUES (?, ?, ?)  [["file", "some file"], ["created_at", 
> "2018-02-04 21:47:54.717609"], ["updated_at", "2018-02-04 
> 21:47:54.717609"]] 
> >   (1.4ms)  commit transaction 
> > => true 
> > 2.4.2 :005 > p.pictures << c 
> >   (0.1ms)  begin transaction 
> >  SQL (0.6ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 1], 
> ["picture_id", 1], ["created_at", "2018-02-04 21:47:58.847298"], 
> ["updated_at", "2018-02-04 21:47:58.847298"]] 
> >   (1.1ms)  commit transaction 
> >  Picture Load (0.4ms)  SELECT  "pictures".* FROM "pictures" INNER JOIN 
> "person_pictures" ON "pictures"."id" = "person_pictures"."picture_id" WHERE 
> "person_pictures"."person_id" = ? LIMIT ?  [["person_id", 1], ["LIMIT", 
> 11]] 
> > => # "some file", created_at: "2018-02-04 21:47:54", updated_at: "2018-02-04 
> 21:47:54">]> 
> > 2.4.2 :006 > 
> > 
> > Here's the models: 
> > 
> > class Picture < ApplicationRecord 
> >  has_many :person_pictures 
> >  has_many :people, through: :person_pictures 
> > end 
> > 
> > class Person < ApplicationRecord 
> >  has_many :person_pictures 
> >  has_many :pictures, through: :person_pictures 
> > end 
> > 
> > class PersonPicture < ApplicationRecord 
> >  belongs_to :person 
> >  belongs_to :picture 
> > end 
> > 
> > Whatever is happening on your app is not clear, but you can see that 
> after you save the person and the picture, when you add that saved picture 
> to the saved person's 'pictures' collection, the only record that gets 
> created is a person_picture. Now if either the person or the picture was in 
> the "new" state, that is to say, not saved yet, then I could imagine that 
> it would be saved by ActiveRecord first in order to allow the 
> person_picture record to be saved. Both IDs have to be known before the 
> join object can be saved. 
> > 
> > Walter 
> > 
> >> On Feb 4, 2018, at 2:30 PM, fugee ohu  
> wrote: 
> >> 
> >> In a has_many_through association where both records exist how do I 
> create a new association 
> >> In this case Person has_many_pictures through person_picture and I'm 
> trying to add an existing picture to an existing person like this: 
> >> @person.pictures << @picture 
> >> But this creates a new picture instead of adding the association 
> >> 
> >> 
> >> -- 
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>  
>
> >> For more options, visit https://groups.google.com/d/optout. 
> > 
> > 

Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Sunday, February 4, 2018 at 6:25:46 PM UTC-5, Walter Lee Davis wrote:
>
> Even more interesting (to me, anyway) is what happens if you create (but 
> don't save) any of these objects: 
>
> 2.4.2 :006 > p = Person.new name: 'Walter' 
>  => # 
> 2.4.2 :007 > c = Picture.new file: 'some file' 
>  => # nil> 
> 2.4.2 :008 > p.pictures << c 
>  => # file: "some file", created_at: nil, updated_at: nil>]> 
> 2.4.2 :009 > p.save 
>(1.9ms)  begin transaction 
>   SQL (23.1ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 23:23:15.342294"], ["updated_at", "2018-02-04 23:23:15.342294"]] 
>   SQL (0.3ms)  INSERT INTO "pictures" ("file", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["file", "some file"], ["created_at", "2018-02-04 
> 23:23:15.374862"], ["updated_at", "2018-02-04 23:23:15.374862"]] 
>   SQL (0.4ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 2], 
> ["picture_id", 2], ["created_at", "2018-02-04 23:23:15.376805"], 
> ["updated_at", "2018-02-04 23:23:15.376805"]] 
>(1.3ms)  commit transaction 
>  => true 
> 2.4.2 :010 > 
>
> When you save one of them, all three are saved in order to preserve the 
> entire set of relationships. 
>
> Walter 
>
> > On Feb 4, 2018, at 4:54 PM, Walter Lee Davis  > wrote: 
> > 
> > I can't duplicate this finding here. Here's the console log: 
> > 
> > 2.4.2 :001 > p = Person.new name: 'Walter' 
> > => # 
> > 2.4.2 :002 > p.save 
> >   (0.2ms)  begin transaction 
> >  SQL (2.8ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 21:47:31.000973"], ["updated_at", "2018-02-04 21:47:31.000973"]] 
> >   (1.3ms)  commit transaction 
> > => true 
> > 2.4.2 :003 > c = Picture.new file: 'some file' 
> > => # nil> 
> > 2.4.2 :004 > c.save 
> >   (0.2ms)  begin transaction 
> >  SQL (2.2ms)  INSERT INTO "pictures" ("file", "created_at", 
> "updated_at") VALUES (?, ?, ?)  [["file", "some file"], ["created_at", 
> "2018-02-04 21:47:54.717609"], ["updated_at", "2018-02-04 
> 21:47:54.717609"]] 
> >   (1.4ms)  commit transaction 
> > => true 
> > 2.4.2 :005 > p.pictures << c 
> >   (0.1ms)  begin transaction 
> >  SQL (0.6ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 1], 
> ["picture_id", 1], ["created_at", "2018-02-04 21:47:58.847298"], 
> ["updated_at", "2018-02-04 21:47:58.847298"]] 
> >   (1.1ms)  commit transaction 
> >  Picture Load (0.4ms)  SELECT  "pictures".* FROM "pictures" INNER JOIN 
> "person_pictures" ON "pictures"."id" = "person_pictures"."picture_id" WHERE 
> "person_pictures"."person_id" = ? LIMIT ?  [["person_id", 1], ["LIMIT", 
> 11]] 
> > => # "some file", created_at: "2018-02-04 21:47:54", updated_at: "2018-02-04 
> 21:47:54">]> 
> > 2.4.2 :006 > 
> > 
> > Here's the models: 
> > 
> > class Picture < ApplicationRecord 
> >  has_many :person_pictures 
> >  has_many :people, through: :person_pictures 
> > end 
> > 
> > class Person < ApplicationRecord 
> >  has_many :person_pictures 
> >  has_many :pictures, through: :person_pictures 
> > end 
> > 
> > class PersonPicture < ApplicationRecord 
> >  belongs_to :person 
> >  belongs_to :picture 
> > end 
> > 
> > Whatever is happening on your app is not clear, but you can see that 
> after you save the person and the picture, when you add that saved picture 
> to the saved person's 'pictures' collection, the only record that gets 
> created is a person_picture. Now if either the person or the picture was in 
> the "new" state, that is to say, not saved yet, then I could imagine that 
> it would be saved by ActiveRecord first in order to allow the 
> person_picture record to be saved. Both IDs have to be known before the 
> join object can be saved. 
> > 
> > Walter 
> > 
> >> On Feb 4, 2018, at 2:30 PM, fugee ohu  
> wrote: 
> >> 
> >> In a has_many_through association where both records exist how do I 
> create a new association 
> >> In this case Person has_many_pictures through person_picture and I'm 
> trying to add an existing picture to an existing person like this: 
> >> @person.pictures << @picture 
> >> But this creates a new picture instead of adding the association 
> >> 
> >> 
> >> -- 
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>
> >> For more options, visit https://groups.google.com/d/optout. 
> > 
> > 

Re: [Rails] has_many_through new association for exisitng records

[Walter Lee Davis]

> On Feb 7, 2018, at 1:43 PM, fugee ohu  wrote:
> 
> 
> 
> On Wednesday, February 7, 2018 at 1:01:02 PM UTC-5, Colin Law wrote:
> On 7 February 2018 at 17:51, fugee ohu  wrote:
> 
> 
> On Wednesday, February 7, 2018 at 12:38:57 PM UTC-5, Colin Law wrote:
> On 7 February 2018 at 17:19, fugee ohu  wrote:
>  
>  I dunno why this doesn't produce any output
> 
> <% @pictures=Picture.all %>
> 
> Model.all has been deprecated since rails 2.3.8.  Don't use it.
>  
> <% @pictures.all do |picture| %>
> 
> this should be using each, not all
> 
> Colin
>  
>   <% if @person %>
>   <% if picture.person_id == @person.id %>
>   <%= check_box_tag 'person[picture_ids][]', 
> picture.id, true %>
>   <% else %>
>  <%= check_box_tag 'person[picture_ids][]', 
> picture.id %>
>   <% end %>
>   <%= image_tag picture.name.thumb %> 
>   <% end %> 
> <% end %>
> 
> 
> 
> 
> I can use <% if picture.person_id == @person.id %> ? This is a 
> has_many_through relationship Person has_many :pictures, through: 
> :person_pictures and also Picture has_many :people, through: :person_pictures 
> What's the right syntax to test if the picture is already associated to the 
> person when iterating through pictures Also if I can't use Model.all in a 
> routine I can still use it to get @pictures=Picture.all right?
> 
> Model.all is deprecated, don't use it.
> 
> If Picture has_many people then you can't use picture.person_id as one 
> picture is associated with many people. so @picture.people is (effectively) 
> an array of people. You will have determine whether the array includes that 
> person.
> 
> Colin
>  
>  
> 
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> 
> For more options, visit https://groups.google.com/d/optout.
> 
> 
> Thanks, yea that's what I meant How do I test for the inclusion of picture in 
> @person.pictures If I can't use Model.all how do I select all pictures from 
> the pictures table?

I would start by setting up @pictures in the controller, not the view.

@pictures = Picture.order :name

Then in the view, you could use that to create your field of checkboxes:

<%- @pictures.each do |picture| %>

Use the presence of that picture's ID in the @person's picture_ids array to set 
or not set the checked attribute
<%= check_box_tag 'person[picture_ids][]', picture.id, 
@person.picture_ids.include?(picture.id) %>
<%= do_something_to_show_a_thumbnail_here %>

<%- end %>

What you will end up doing is mutating the picture_ids array in this form. As 
long as you have allowed that (and defined it as requiring an array) in your 
whitelist, then the association will have built the necessary accessor methods 
and this will all just work.

Walter

> 
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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Wednesday, February 7, 2018 at 1:01:02 PM UTC-5, Colin Law wrote:
>
> On 7 February 2018 at 17:51, fugee ohu  
> wrote:
>
>>
>>
>> On Wednesday, February 7, 2018 at 12:38:57 PM UTC-5, Colin Law wrote:
>>>
>>> On 7 February 2018 at 17:19, fugee ohu  wrote:
>>>
  
  I dunno why this doesn't produce any output

 <% @pictures=Picture.all %>

>>>
>>> Model.all has been deprecated since rails 2.3.8.  Don't use it.
>>>  
>>>
 <% @pictures.all do |picture| %>

>>>
>>> this should be using each, not all
>>>
>>> Colin
>>>  
>>>
 <% if @person %>
 <% if picture.person_id == @person.id %>
 <%= check_box_tag 'person[picture_ids][]', picture.id, true %>
 <% else %>
<%= check_box_tag 'person[picture_ids][]', picture.id %>
 <% end %>
 <%= image_tag picture.name.thumb %> 
 <% end %> 
 <% end %>

>>>
>>>
>>>
>>>
>> I can use  <% if picture.person_id == @person.id %> ? This is a 
>> has_many_through relationship Person has_many :pictures, through: 
>> :person_pictures and also Picture has_many :people, through: 
>> :person_pictures What's the right syntax to test if the picture is already 
>> associated to the person when iterating through pictures Also if I can't 
>> use Model.all in a routine I can still use it to get @pictures=Picture.all 
>> right?
>>
>
> Model.all is deprecated, don't use it.
>
> If Picture has_many people then you can't use picture.person_id as one 
> picture is associated with many people. so @picture.people is (effectively) 
> an array of people. You will have determine whether the array includes that 
> person.
>
> Colin
>  
>
>>  
>>
>> -- 
>> You received this message because you are subscribed to the Google Groups 
>> "Ruby on Rails: Talk" group.
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>> email to rubyonrails-ta...@googlegroups.com .
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>> .
>> To view this discussion on the web visit 
>> https://groups.google.com/d/msgid/rubyonrails-talk/8d160a04-6951-4159-bfa7-8eee046cb3c4%40googlegroups.com
>>  
>> 
>> .
>>
>> For more options, visit https://groups.google.com/d/optout.
>>
>
>
Thanks, yea that's what I meant How do I test for the inclusion of picture 
in @person.pictures If I can't use Model.all how do I select all pictures 
from the pictures table?

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Re: [Rails] has_many_through new association for exisitng records

[Colin Law]

On 7 February 2018 at 17:51, fugee ohu  wrote:

>
>
> On Wednesday, February 7, 2018 at 12:38:57 PM UTC-5, Colin Law wrote:
>>
>> On 7 February 2018 at 17:19, fugee ohu  wrote:
>>
>>>
>>>  I dunno why this doesn't produce any output
>>>
>>> <% @pictures=Picture.all %>
>>>
>>
>> Model.all has been deprecated since rails 2.3.8.  Don't use it.
>>
>>
>>> <% @pictures.all do |picture| %>
>>>
>>
>> this should be using each, not all
>>
>> Colin
>>
>>
>>> <% if @person %>
>>> <% if picture.person_id == @person.id %>
>>> <%= check_box_tag 'person[picture_ids][]', picture.id, true %>
>>> <% else %>
>>><%= check_box_tag 'person[picture_ids][]', picture.id %>
>>> <% end %>
>>> <%= image_tag picture.name.thumb %>
>>> <% end %>
>>> <% end %>
>>>
>>
>>
>>
>>
> I can use  <% if picture.person_id == @person.id %> ? This is a
> has_many_through relationship Person has_many :pictures, through:
> :person_pictures and also Picture has_many :people, through:
> :person_pictures What's the right syntax to test if the picture is already
> associated to the person when iterating through pictures Also if I can't
> use Model.all in a routine I can still use it to get @pictures=Picture.all
> right?
>

Model.all is deprecated, don't use it.

If Picture has_many people then you can't use picture.person_id as one
picture is associated with many people. so @picture.people is (effectively)
an array of people. You will have determine whether the array includes that
person.

Colin


>
>
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> msgid/rubyonrails-talk/8d160a04-6951-4159-bfa7-
> 8eee046cb3c4%40googlegroups.com
> 
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>
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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Wednesday, February 7, 2018 at 12:38:57 PM UTC-5, Colin Law wrote:
>
> On 7 February 2018 at 17:19, fugee ohu  
> wrote:
>
>>  
>>  I dunno why this doesn't produce any output
>>
>> <% @pictures=Picture.all %>
>>
>
> Model.all has been deprecated since rails 2.3.8.  Don't use it.
>  
>
>> <% @pictures.all do |picture| %>
>>
>
> this should be using each, not all
>
> Colin
>  
>
>> <% if @person %>
>> <% if picture.person_id == @person.id %>
>> <%= check_box_tag 'person[picture_ids][]', picture.id, true %>
>> <% else %>
>><%= check_box_tag 'person[picture_ids][]', picture.id %>
>> <% end %>
>> <%= image_tag picture.name.thumb %> 
>> <% end %> 
>> <% end %>
>>
>
>
>
>
I can use  <% if picture.person_id == @person.id %> ? This is a 
has_many_through relationship Person has_many :pictures, through: 
:person_pictures and also Picture has_many :people, through: 
:person_pictures What's the right syntax to test if the picture is already 
associated to the person when iterating through pictures Also if I can't 
use Model.all in a routine I can still use it to get @pictures=Picture.all 
right?
 

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Re: [Rails] has_many_through new association for exisitng records

[Colin Law]

On 7 February 2018 at 17:19, fugee ohu  wrote:

>
>  I dunno why this doesn't produce any output
>
> <% @pictures=Picture.all %>
>

Model.all has been deprecated since rails 2.3.8.  Don't use it.


> <% @pictures.all do |picture| %>
>

this should be using each, not all

Colin


> <% if @person %>
> <% if picture.person_id == @person.id %>
> <%= check_box_tag 'person[picture_ids][]', picture.id, true %>
> <% else %>
><%= check_box_tag 'person[picture_ids][]', picture.id %>
> <% end %>
> <%= image_tag picture.name.thumb %>
> <% end %>
> <% end %>
>

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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Monday, February 5, 2018 at 11:46:24 AM UTC-5, Walter Lee Davis wrote:
>
> You (effectively) delete the intermediate object. You could try one of two 
> things: 
>
> @person.pictures -= [@picture] 
>
> If all the items are persisted, then that should delete the join object 
> immediately. (Just tested, it did work here.) 
>
> @person.pictures = @person.pictures.to_a.reject{ |p| p == @picture } 
>
> (Long-hand way to do the same thing) 
>
> Now if you have a UI around this, what you would do is build an array of 
> checkboxes with the picture IDs in them, and then use the helper method 
> @person.picture_ids=(array of ids) that the association built for you. You 
> don't need to do any of the above long-hand. 
>
> So in your controller, you would add picture_ids: [] to the end of your 
> list of allowed attributes in the strong parameters. Next, you would create 
> a checkbox for each attached image in your form: 
>
> <%- @person.pictures.each do |picture| %> 
> <%= check_box_tag 'person[picture_ids][]', picture.id, true %> 
> <%= image_tag picture.file_url %> (just guessing how your internals look, 
> do something here to show a thumbnail) 
> <%- end %> 
>
> And that should do the whole thing for you. 
>
> Walter 
>
> > On Feb 5, 2018, at 1:18 AM, fugee ohu  
> wrote: 
> > 
> > So if @person.pictures << @picture adds a picture to a person, how do 
> you remove a picture from a person? 
> > 
> > 
>
>  
 I dunno why this doesn't produce any output

<% @pictures=Picture.all %>
<% @pictures.all do |picture| %>
<% if @person %>
<% if picture.person_id == @person.id %>
<%= check_box_tag 'person[picture_ids][]', picture.id, true %>
<% else %>
   <%= check_box_tag 'person[picture_ids][]', picture.id %>
<% end %>
<%= image_tag picture.name.thumb %> 
<% end %> 
<% end %>

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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Monday, February 5, 2018 at 11:46:24 AM UTC-5, Walter Lee Davis wrote:
>
> You (effectively) delete the intermediate object. You could try one of two 
> things: 
>
> @person.pictures -= [@picture] 
>
> If all the items are persisted, then that should delete the join object 
> immediately. (Just tested, it did work here.) 
>
> @person.pictures = @person.pictures.to_a.reject{ |p| p == @picture } 
>
> (Long-hand way to do the same thing) 
>
> Now if you have a UI around this, what you would do is build an array of 
> checkboxes with the picture IDs in them, and then use the helper method 
> @person.picture_ids=(array of ids) that the association built for you. You 
> don't need to do any of the above long-hand. 
>
> So in your controller, you would add picture_ids: [] to the end of your 
> list of allowed attributes in the strong parameters. Next, you would create 
> a checkbox for each attached image in your form: 
>
> <%- @person.pictures.each do |picture| %> 
> <%= check_box_tag 'person[picture_ids][]', picture.id, true %> 
> <%= image_tag picture.file_url %> (just guessing how your internals look, 
> do something here to show a thumbnail) 
> <%- end %> 
>
> And that should do the whole thing for you. 
>
> Walter 
>
> > On Feb 5, 2018, at 1:18 AM, fugee ohu  
> wrote: 
> > 
> > So if @person.pictures << @picture adds a picture to a person, how do 
> you remove a picture from a person? 
> > 
> > 
>
>
I need to select from all pictures and if the picture's already associated 
with the person it would already be checked then I guess, something like 
that

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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Monday, February 5, 2018 at 11:46:24 AM UTC-5, Walter Lee Davis wrote:
>
> You (effectively) delete the intermediate object. You could try one of two 
> things: 
>
> @person.pictures -= [@picture] 
>
> If all the items are persisted, then that should delete the join object 
> immediately. (Just tested, it did work here.) 
>
> @person.pictures = @person.pictures.to_a.reject{ |p| p == @picture } 
>
> (Long-hand way to do the same thing) 
>
> Now if you have a UI around this, what you would do is build an array of 
> checkboxes with the picture IDs in them, and then use the helper method 
> @person.picture_ids=(array of ids) that the association built for you. You 
> don't need to do any of the above long-hand. 
>
> So in your controller, you would add picture_ids: [] to the end of your 
> list of allowed attributes in the strong parameters. Next, you would create 
> a checkbox for each attached image in your form: 
>
> <%- @person.pictures.each do |picture| %> 
> <%= check_box_tag 'person[picture_ids][]', picture.id, true %> 
> <%= image_tag picture.file_url %> (just guessing how your internals look, 
> do something here to show a thumbnail) 
> <%- end %> 
>
> And that should do the whole thing for you. 
>
> Walter 
>
> > On Feb 5, 2018, at 1:18 AM, fugee ohu  
> wrote: 
> > 
> > So if @person.pictures << @picture adds a picture to a person, how do 
> you remove a picture from a person? 
> > 
> > 
>
>
Yea, that's pretty good thanks What about  the gem that let you use images 
in select lists I would think a lot of images is too many for a select list

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Re: [Rails] has_many_through new association for exisitng records

[Walter Lee Davis]

You (effectively) delete the intermediate object. You could try one of two 
things:

@person.pictures -= [@picture]

If all the items are persisted, then that should delete the join object 
immediately. (Just tested, it did work here.)

@person.pictures = @person.pictures.to_a.reject{ |p| p == @picture }

(Long-hand way to do the same thing)

Now if you have a UI around this, what you would do is build an array of 
checkboxes with the picture IDs in them, and then use the helper method 
@person.picture_ids=(array of ids) that the association built for you. You 
don't need to do any of the above long-hand.

So in your controller, you would add picture_ids: [] to the end of your list of 
allowed attributes in the strong parameters. Next, you would create a checkbox 
for each attached image in your form:

<%- @person.pictures.each do |picture| %>
<%= check_box_tag 'person[picture_ids][]', picture.id, true %>
<%= image_tag picture.file_url %> (just guessing how your internals look, do 
something here to show a thumbnail)
<%- end %>

And that should do the whole thing for you.

Walter

> On Feb 5, 2018, at 1:18 AM, fugee ohu  wrote:
> 
> So if @person.pictures << @picture adds a picture to a person, how do you 
> remove a picture from a person?
> 
> 

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Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Sunday, February 4, 2018 at 6:25:46 PM UTC-5, Walter Lee Davis wrote:
>
> Even more interesting (to me, anyway) is what happens if you create (but 
> don't save) any of these objects: 
>
> 2.4.2 :006 > p = Person.new name: 'Walter' 
>  => # 
> 2.4.2 :007 > c = Picture.new file: 'some file' 
>  => # nil> 
> 2.4.2 :008 > p.pictures << c 
>  => # file: "some file", created_at: nil, updated_at: nil>]> 
> 2.4.2 :009 > p.save 
>(1.9ms)  begin transaction 
>   SQL (23.1ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 23:23:15.342294"], ["updated_at", "2018-02-04 23:23:15.342294"]] 
>   SQL (0.3ms)  INSERT INTO "pictures" ("file", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["file", "some file"], ["created_at", "2018-02-04 
> 23:23:15.374862"], ["updated_at", "2018-02-04 23:23:15.374862"]] 
>   SQL (0.4ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 2], 
> ["picture_id", 2], ["created_at", "2018-02-04 23:23:15.376805"], 
> ["updated_at", "2018-02-04 23:23:15.376805"]] 
>(1.3ms)  commit transaction 
>  => true 
> 2.4.2 :010 > 
>
> When you save one of them, all three are saved in order to preserve the 
> entire set of relationships. 
>
> Walter 
>
> > On Feb 4, 2018, at 4:54 PM, Walter Lee Davis  > wrote: 
> > 
> > I can't duplicate this finding here. Here's the console log: 
> > 
> > 2.4.2 :001 > p = Person.new name: 'Walter' 
> > => # 
> > 2.4.2 :002 > p.save 
> >   (0.2ms)  begin transaction 
> >  SQL (2.8ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 21:47:31.000973"], ["updated_at", "2018-02-04 21:47:31.000973"]] 
> >   (1.3ms)  commit transaction 
> > => true 
> > 2.4.2 :003 > c = Picture.new file: 'some file' 
> > => # nil> 
> > 2.4.2 :004 > c.save 
> >   (0.2ms)  begin transaction 
> >  SQL (2.2ms)  INSERT INTO "pictures" ("file", "created_at", 
> "updated_at") VALUES (?, ?, ?)  [["file", "some file"], ["created_at", 
> "2018-02-04 21:47:54.717609"], ["updated_at", "2018-02-04 
> 21:47:54.717609"]] 
> >   (1.4ms)  commit transaction 
> > => true 
> > 2.4.2 :005 > p.pictures << c 
> >   (0.1ms)  begin transaction 
> >  SQL (0.6ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 1], 
> ["picture_id", 1], ["created_at", "2018-02-04 21:47:58.847298"], 
> ["updated_at", "2018-02-04 21:47:58.847298"]] 
> >   (1.1ms)  commit transaction 
> >  Picture Load (0.4ms)  SELECT  "pictures".* FROM "pictures" INNER JOIN 
> "person_pictures" ON "pictures"."id" = "person_pictures"."picture_id" WHERE 
> "person_pictures"."person_id" = ? LIMIT ?  [["person_id", 1], ["LIMIT", 
> 11]] 
> > => # "some file", created_at: "2018-02-04 21:47:54", updated_at: "2018-02-04 
> 21:47:54">]> 
> > 2.4.2 :006 > 
> > 
> > Here's the models: 
> > 
> > class Picture < ApplicationRecord 
> >  has_many :person_pictures 
> >  has_many :people, through: :person_pictures 
> > end 
> > 
> > class Person < ApplicationRecord 
> >  has_many :person_pictures 
> >  has_many :pictures, through: :person_pictures 
> > end 
> > 
> > class PersonPicture < ApplicationRecord 
> >  belongs_to :person 
> >  belongs_to :picture 
> > end 
> > 
> > Whatever is happening on your app is not clear, but you can see that 
> after you save the person and the picture, when you add that saved picture 
> to the saved person's 'pictures' collection, the only record that gets 
> created is a person_picture. Now if either the person or the picture was in 
> the "new" state, that is to say, not saved yet, then I could imagine that 
> it would be saved by ActiveRecord first in order to allow the 
> person_picture record to be saved. Both IDs have to be known before the 
> join object can be saved. 
> > 
> > Walter 
> > 
> >> On Feb 4, 2018, at 2:30 PM, fugee ohu  
> wrote: 
> >> 
> >> In a has_many_through association where both records exist how do I 
> create a new association 
> >> In this case Person has_many_pictures through person_picture and I'm 
> trying to add an existing picture to an existing person like this: 
> >> @person.pictures << @picture 
> >> But this creates a new picture instead of adding the association 
> >> 
> >> 
> >> -- 
> >> You received this message because you are subscribed to the Google 
> Groups "Ruby on Rails: Talk" group. 
> >> To unsubscribe from this group and stop receiving emails from it, send 
> an email to rubyonrails-ta...@googlegroups.com . 
> >> To post to this group, send email to rubyonra...@googlegroups.com 
> . 
> >> To view this discussion on the web visit 
> https://groups.google.com/d/msgid/rubyonrails-talk/741e9a16-483f-4fc6-a2e7-77706b9b250c%40googlegroups.com.
>  
>
> >> For more options, visit https://groups.google.com/d/optout. 
> > 
> > 

Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Sunday, February 4, 2018 at 6:25:46 PM UTC-5, Walter Lee Davis wrote:
>
> Even more interesting (to me, anyway) is what happens if you create (but 
> don't save) any of these objects: 
>
> 2.4.2 :006 > p = Person.new name: 'Walter' 
>  => # 
> 2.4.2 :007 > c = Picture.new file: 'some file' 
>  => # nil> 
> 2.4.2 :008 > p.pictures << c 
>  => # file: "some file", created_at: nil, updated_at: nil>]> 
> 2.4.2 :009 > p.save 
>(1.9ms)  begin transaction 
>   SQL (23.1ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 23:23:15.342294"], ["updated_at", "2018-02-04 23:23:15.342294"]] 
>   SQL (0.3ms)  INSERT INTO "pictures" ("file", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["file", "some file"], ["created_at", "2018-02-04 
> 23:23:15.374862"], ["updated_at", "2018-02-04 23:23:15.374862"]] 
>   SQL (0.4ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 2], 
> ["picture_id", 2], ["created_at", "2018-02-04 23:23:15.376805"], 
> ["updated_at", "2018-02-04 23:23:15.376805"]] 
>(1.3ms)  commit transaction 
>  => true 
> 2.4.2 :010 > 
>
> When you save one of them, all three are saved in order to preserve the 
> entire set of relationships. 
>
> Walter 
>
> > On Feb 4, 2018, at 4:54 PM, Walter Lee Davis  > wrote: 
> > 
> > I can't duplicate this finding here. Here's the console log: 
> > 
> > 2.4.2 :001 > p = Person.new name: 'Walter' 
> > => # 
> > 2.4.2 :002 > p.save 
> >   (0.2ms)  begin transaction 
> >  SQL (2.8ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 21:47:31.000973"], ["updated_at", "2018-02-04 21:47:31.000973"]] 
> >   (1.3ms)  commit transaction 
> > => true 
> > 2.4.2 :003 > c = Picture.new file: 'some file' 
> > => # nil> 
> > 2.4.2 :004 > c.save 
> >   (0.2ms)  begin transaction 
> >  SQL (2.2ms)  INSERT INTO "pictures" ("file", "created_at", 
> "updated_at") VALUES (?, ?, ?)  [["file", "some file"], ["created_at", 
> "2018-02-04 21:47:54.717609"], ["updated_at", "2018-02-04 
> 21:47:54.717609"]] 
> >   (1.4ms)  commit transaction 
> > => true 
> > 2.4.2 :005 > p.pictures << c 
> >   (0.1ms)  begin transaction 
> >  SQL (0.6ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 1], 
> ["picture_id", 1], ["created_at", "2018-02-04 21:47:58.847298"], 
> ["updated_at", "2018-02-04 21:47:58.847298"]] 
> >   (1.1ms)  commit transaction 
> >  Picture Load (0.4ms)  SELECT  "pictures".* FROM "pictures" INNER JOIN 
> "person_pictures" ON "pictures"."id" = "person_pictures"."picture_id" WHERE 
> "person_pictures"."person_id" = ? LIMIT ?  [["person_id", 1], ["LIMIT", 
> 11]] 
> > => # "some file", created_at: "2018-02-04 21:47:54", updated_at: "2018-02-04 
> 21:47:54">]> 
> > 2.4.2 :006 > 
> > 
> > Here's the models: 
> > 
> > class Picture < ApplicationRecord 
> >  has_many :person_pictures 
> >  has_many :people, through: :person_pictures 
> > end 
> > 
> > class Person < ApplicationRecord 
> >  has_many :person_pictures 
> >  has_many :pictures, through: :person_pictures 
> > end 
> > 
> > class PersonPicture < ApplicationRecord 
> >  belongs_to :person 
> >  belongs_to :picture 
> > end 
> > 
> > Whatever is happening on your app is not clear, but you can see that 
> after you save the person and the picture, when you add that saved picture 
> to the saved person's 'pictures' collection, the only record that gets 
> created is a person_picture. Now if either the person or the picture was in 
> the "new" state, that is to say, not saved yet, then I could imagine that 
> it would be saved by ActiveRecord first in order to allow the 
> person_picture record to be saved. Both IDs have to be known before the 
> join object can be saved. 
> > 
> > Walter 
> > 
> >> On Feb 4, 2018, at 2:30 PM, fugee ohu  
> wrote: 
> >> 
> >> In a has_many_through association where both records exist how do I 
> create a new association 
> >> In this case Person has_many_pictures through person_picture and I'm 
> trying to add an existing picture to an existing person like this: 
> >> @person.pictures << @picture 
> >> But this creates a new picture instead of adding the association 
> >> 
> >> 
> >> -- 
> >> You received this message because you are subscribed to the Google 
> Groups "Ruby on Rails: Talk" group. 
> >> To unsubscribe from this group and stop receiving emails from it, send 
> an email to rubyonrails-ta...@googlegroups.com . 
> >> To post to this group, send email to rubyonra...@googlegroups.com 
> . 
> >> To view this discussion on the web visit 
> https://groups.google.com/d/msgid/rubyonrails-talk/741e9a16-483f-4fc6-a2e7-77706b9b250c%40googlegroups.com.
>  
>
> >> For more options, visit https://groups.google.com/d/optout. 
> > 
> > 

Re: [Rails] has_many_through new association for exisitng records

[fugee ohu]

On Sunday, February 4, 2018 at 4:55:08 PM UTC-5, Walter Lee Davis wrote:
>
> I can't duplicate this finding here. Here's the console log: 
>
> 2.4.2 :001 > p = Person.new name: 'Walter' 
>  => # 
> 2.4.2 :002 > p.save 
>(0.2ms)  begin transaction 
>   SQL (2.8ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 21:47:31.000973"], ["updated_at", "2018-02-04 21:47:31.000973"]] 
>(1.3ms)  commit transaction 
>  => true 
> 2.4.2 :003 > c = Picture.new file: 'some file' 
>  => # nil> 
> 2.4.2 :004 > c.save 
>(0.2ms)  begin transaction 
>   SQL (2.2ms)  INSERT INTO "pictures" ("file", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["file", "some file"], ["created_at", "2018-02-04 
> 21:47:54.717609"], ["updated_at", "2018-02-04 21:47:54.717609"]] 
>(1.4ms)  commit transaction 
>  => true 
> 2.4.2 :005 > p.pictures << c 
>(0.1ms)  begin transaction 
>   SQL (0.6ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 1], 
> ["picture_id", 1], ["created_at", "2018-02-04 21:47:58.847298"], 
> ["updated_at", "2018-02-04 21:47:58.847298"]] 
>(1.1ms)  commit transaction 
>   Picture Load (0.4ms)  SELECT  "pictures".* FROM "pictures" INNER JOIN 
> "person_pictures" ON "pictures"."id" = "person_pictures"."picture_id" WHERE 
> "person_pictures"."person_id" = ? LIMIT ?  [["person_id", 1], ["LIMIT", 
> 11]] 
>  => # "some file", created_at: "2018-02-04 21:47:54", updated_at: "2018-02-04 
> 21:47:54">]> 
> 2.4.2 :006 > 
>
> Here's the models: 
>
> class Picture < ApplicationRecord 
>   has_many :person_pictures 
>   has_many :people, through: :person_pictures 
> end 
>
> class Person < ApplicationRecord 
>   has_many :person_pictures 
>   has_many :pictures, through: :person_pictures 
> end 
>
> class PersonPicture < ApplicationRecord 
>   belongs_to :person 
>   belongs_to :picture 
> end 
>
> Whatever is happening on your app is not clear, but you can see that after 
> you save the person and the picture, when you add that saved picture to the 
> saved person's 'pictures' collection, the only record that gets created is 
> a person_picture. Now if either the person or the picture was in the "new" 
> state, that is to say, not saved yet, then I could imagine that it would be 
> saved by ActiveRecord first in order to allow the person_picture record to 
> be saved. Both IDs have to be known before the join object can be saved. 
>
> Walter 
>
> > On Feb 4, 2018, at 2:30 PM, fugee ohu  
> wrote: 
> > 
> > In a has_many_through association where both records exist how do I 
> create a new association 
> > In this case Person has_many_pictures through person_picture and I'm 
> trying to add an existing picture to an existing person like this: 
> > @person.pictures << @picture 
> > But this creates a new picture instead of adding the association 
> > 
> > 
> > -- 
> > You received this message because you are subscribed to the Google 
> Groups "Ruby on Rails: Talk" group. 
> > To unsubscribe from this group and stop receiving emails from it, send 
> an email to rubyonrails-ta...@googlegroups.com . 
> > To post to this group, send email to rubyonra...@googlegroups.com 
> . 
> > To view this discussion on the web visit 
> https://groups.google.com/d/msgid/rubyonrails-talk/741e9a16-483f-4fc6-a2e7-77706b9b250c%40googlegroups.com.
>  
>
> > For more options, visit https://groups.google.com/d/optout. 
>
>
class PersonPicture < ApplicationRecord
 belongs_to :person
 belongs_to :picture
end

class Picture < ApplicationRecord
 has_many :person_pictures
 has_many :people, through: :person_picture

class Person < ApplicationRecord
 has_many :person_pictures
 has_many :pictures, through: :person_pictures

@pictures = Person.find(params[:person_id]).pictures.all causes the error 
ActiveRecord::HasManyThroughAssociationNotFoundError in 
PicturesController#index
Could not find the association :person_picture in model Person

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Re: [Rails] has_many_through new association for exisitng records

[Walter Lee Davis]

Even more interesting (to me, anyway) is what happens if you create (but don't 
save) any of these objects:

2.4.2 :006 > p = Person.new name: 'Walter'
 => # 
2.4.2 :007 > c = Picture.new file: 'some file'
 => # 
2.4.2 :008 > p.pictures << c
 => #]> 
2.4.2 :009 > p.save
   (1.9ms)  begin transaction
  SQL (23.1ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
23:23:15.342294"], ["updated_at", "2018-02-04 23:23:15.342294"]]
  SQL (0.3ms)  INSERT INTO "pictures" ("file", "created_at", "updated_at") 
VALUES (?, ?, ?)  [["file", "some file"], ["created_at", "2018-02-04 
23:23:15.374862"], ["updated_at", "2018-02-04 23:23:15.374862"]]
  SQL (0.4ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
"created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 2], 
["picture_id", 2], ["created_at", "2018-02-04 23:23:15.376805"], ["updated_at", 
"2018-02-04 23:23:15.376805"]]
   (1.3ms)  commit transaction
 => true 
2.4.2 :010 > 

When you save one of them, all three are saved in order to preserve the entire 
set of relationships.

Walter

> On Feb 4, 2018, at 4:54 PM, Walter Lee Davis  wrote:
> 
> I can't duplicate this finding here. Here's the console log:
> 
> 2.4.2 :001 > p = Person.new name: 'Walter'
> => # 
> 2.4.2 :002 > p.save
>   (0.2ms)  begin transaction
>  SQL (2.8ms)  INSERT INTO "people" ("name", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 
> 21:47:31.000973"], ["updated_at", "2018-02-04 21:47:31.000973"]]
>   (1.3ms)  commit transaction
> => true 
> 2.4.2 :003 > c = Picture.new file: 'some file'
> => # 
> 2.4.2 :004 > c.save
>   (0.2ms)  begin transaction
>  SQL (2.2ms)  INSERT INTO "pictures" ("file", "created_at", "updated_at") 
> VALUES (?, ?, ?)  [["file", "some file"], ["created_at", "2018-02-04 
> 21:47:54.717609"], ["updated_at", "2018-02-04 21:47:54.717609"]]
>   (1.4ms)  commit transaction
> => true 
> 2.4.2 :005 > p.pictures << c
>   (0.1ms)  begin transaction
>  SQL (0.6ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
> "created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 1], 
> ["picture_id", 1], ["created_at", "2018-02-04 21:47:58.847298"], 
> ["updated_at", "2018-02-04 21:47:58.847298"]]
>   (1.1ms)  commit transaction
>  Picture Load (0.4ms)  SELECT  "pictures".* FROM "pictures" INNER JOIN 
> "person_pictures" ON "pictures"."id" = "person_pictures"."picture_id" WHERE 
> "person_pictures"."person_id" = ? LIMIT ?  [["person_id", 1], ["LIMIT", 11]]
> => # "some file", created_at: "2018-02-04 21:47:54", updated_at: "2018-02-04 
> 21:47:54">]> 
> 2.4.2 :006 > 
> 
> Here's the models:
> 
> class Picture < ApplicationRecord
>  has_many :person_pictures
>  has_many :people, through: :person_pictures
> end
> 
> class Person < ApplicationRecord
>  has_many :person_pictures
>  has_many :pictures, through: :person_pictures
> end
> 
> class PersonPicture < ApplicationRecord
>  belongs_to :person
>  belongs_to :picture
> end
> 
> Whatever is happening on your app is not clear, but you can see that after 
> you save the person and the picture, when you add that saved picture to the 
> saved person's 'pictures' collection, the only record that gets created is a 
> person_picture. Now if either the person or the picture was in the "new" 
> state, that is to say, not saved yet, then I could imagine that it would be 
> saved by ActiveRecord first in order to allow the person_picture record to be 
> saved. Both IDs have to be known before the join object can be saved.
> 
> Walter
> 
>> On Feb 4, 2018, at 2:30 PM, fugee ohu  wrote:
>> 
>> In a has_many_through association where both records exist how do I create a 
>> new association
>> In this case Person has_many_pictures through person_picture and I'm trying 
>> to add an existing picture to an existing person like this:
>> @person.pictures << @picture
>> But this creates a new picture instead of adding the association
>> 
>> 
>> -- 
>> You received this message because you are subscribed to the Google Groups 
>> "Ruby on Rails: Talk" group.
>> To unsubscribe from this group and stop receiving emails from it, send an 
>> email to rubyonrails-talk+unsubscr...@googlegroups.com.
>> To post to this group, send email to rubyonrails-talk@googlegroups.com.
>> To view this discussion on the web visit 
>> https://groups.google.com/d/msgid/rubyonrails-talk/741e9a16-483f-4fc6-a2e7-77706b9b250c%40googlegroups.com.
>> For more options, visit https://groups.google.com/d/optout.
> 
> -- 
> You received this message because you are subscribed to the Google Groups 
> "Ruby on Rails: Talk" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
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> To post to this group, send email to rubyonrails-talk@googlegroups.com.
> To view this discussion on the web visit 
> 

Re: [Rails] has_many_through new association for exisitng records

[Walter Lee Davis]

I can't duplicate this finding here. Here's the console log:

2.4.2 :001 > p = Person.new name: 'Walter'
 => # 
2.4.2 :002 > p.save
   (0.2ms)  begin transaction
  SQL (2.8ms)  INSERT INTO "people" ("name", "created_at", "updated_at") VALUES 
(?, ?, ?)  [["name", "Walter"], ["created_at", "2018-02-04 21:47:31.000973"], 
["updated_at", "2018-02-04 21:47:31.000973"]]
   (1.3ms)  commit transaction
 => true 
2.4.2 :003 > c = Picture.new file: 'some file'
 => # 
2.4.2 :004 > c.save
   (0.2ms)  begin transaction
  SQL (2.2ms)  INSERT INTO "pictures" ("file", "created_at", "updated_at") 
VALUES (?, ?, ?)  [["file", "some file"], ["created_at", "2018-02-04 
21:47:54.717609"], ["updated_at", "2018-02-04 21:47:54.717609"]]
   (1.4ms)  commit transaction
 => true 
2.4.2 :005 > p.pictures << c
   (0.1ms)  begin transaction
  SQL (0.6ms)  INSERT INTO "person_pictures" ("person_id", "picture_id", 
"created_at", "updated_at") VALUES (?, ?, ?, ?)  [["person_id", 1], 
["picture_id", 1], ["created_at", "2018-02-04 21:47:58.847298"], ["updated_at", 
"2018-02-04 21:47:58.847298"]]
   (1.1ms)  commit transaction
  Picture Load (0.4ms)  SELECT  "pictures".* FROM "pictures" INNER JOIN 
"person_pictures" ON "pictures"."id" = "person_pictures"."picture_id" WHERE 
"person_pictures"."person_id" = ? LIMIT ?  [["person_id", 1], ["LIMIT", 11]]
 => #]> 
2.4.2 :006 > 

Here's the models:

class Picture < ApplicationRecord
  has_many :person_pictures
  has_many :people, through: :person_pictures
end

class Person < ApplicationRecord
  has_many :person_pictures
  has_many :pictures, through: :person_pictures
end

class PersonPicture < ApplicationRecord
  belongs_to :person
  belongs_to :picture
end

Whatever is happening on your app is not clear, but you can see that after you 
save the person and the picture, when you add that saved picture to the saved 
person's 'pictures' collection, the only record that gets created is a 
person_picture. Now if either the person or the picture was in the "new" state, 
that is to say, not saved yet, then I could imagine that it would be saved by 
ActiveRecord first in order to allow the person_picture record to be saved. 
Both IDs have to be known before the join object can be saved.

Walter

> On Feb 4, 2018, at 2:30 PM, fugee ohu  wrote:
> 
> In a has_many_through association where both records exist how do I create a 
> new association
> In this case Person has_many_pictures through person_picture and I'm trying 
> to add an existing picture to an existing person like this:
> @person.pictures << @picture
> But this creates a new picture instead of adding the association
> 
> 
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[Rails] has_many_through new association for exisitng records

[fugee ohu]

In a has_many_through association where both records exist how do I create 
a new association
In this case Person has_many_pictures through person_picture and I'm trying 
to add an existing picture to an existing person like this:
@person.pictures << @picture
But this creates a new picture instead of adding the association

-- 
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on Rails: Talk" group.
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