retrieve unupdated attribute

[Samuel Laulhau]

I have a model with an image, my model as a attribute image with the name of the image.
While I save it I want to make some manipulation on this image if the attribute is dirty and I would like to remove the old image file.

Today to retrieve the old file name I have to make a new request, I think the orm can keep the new and the old value of the field while it's dirty.

Especially the object have an property _dirty_fields which is an array off each field qith the new value duplicated. So why don't put the original value here instead of the new one ?

[Simon Holywell]

I may be missing something, but can't you just clone the instance?

$my_model = Model::factory('MyModel')->find_one();
$my_model->my_property = 'something';

$my_model2 = clone $my_model;

$my_model->another_property = 'value';

if(some_condition) {
    $my_model->another_property = $my_model2->another_property;
}
$my_model->save();

Idiorm doesn't output the original value as this would be confusing. If you call $object->var = 1; then you naturally expect to get var_dump($object->var); // 1.

[Samuel Laulhau]

What id $object->var ?

Yes it's effectively what I'm expecting but if I do var_dump($object) I can see that the object contains an array with updated property and their updated value : $object->orm->_dirty_fields
What is the interest of this property ? This could has the original value and _data the updated value, a simple key matching will give the dirty fields.

[Simon Holywell]

To be honest I do not have a clue why it has been done that way. Perhaps it was a pull request that was merged or perhaps that is how @j4mie wrote it. It has been a little while now since it was written so I am not even sure that Jamie would know the reasons why.

Anyway I am going to close this ticket as I think we have reached an answer on the technical problem and unfortunately I do not have any more information on the reasons why.

Feel free to re-open if you have more you want to ask.

[Samuel Laulhau]

To start it was more a functional improvement than an technical answer on how add this improvement.

What do you think of the functionality ?

[Simon Holywell]

Without giving it too much thought it would appear to be backwards incompatible to me. Have you got thoughts on that?

[Samuel Laulhau]

That wiil affect idiorm more than paris since the dirty property is in it but the idea is to build request with the value registred in the _data property rather than them in _dirty. Keeping dirty property to mark an attribute has updated and not saved but registring in it the originla value not the new one ( this one is actually already registred in _data ).
One time that is made, all would run normally and you can add a method like orinal_value($key) that will return the value found in database if the model isn't saved.
You just have to report that to paris in a second time.

I can make a pull request to idiorm if you think that can be interesting.

[Simon Holywell]

I really don't see the need or what this gives over using PHP's clone construct. I would suggest that this a rare use case and that there are probably better ways of working this without resorting to changing a long standing part of the library.

[Samuel Laulhau]

You can see a use case in my first comment for an image attachment.
If I use the clone method in save method it's to late, to prevent that I have to clone every object at the creation... I think that is not the good way.
You can see here the ror implementation of the dirty feature http://api.rubyonrails.org/classes/ActiveModel/Dirty.html

Do you see the point ?

[Simon Holywell]

Just assign that value to a variable before you overwrite it or clone the object. I am not going to change this part of the library for backwards compatibility reasons.

This issue is closed.