How can I interact with objects I've created based on their given attributes in Ruby?
To give some context, I'm parsing a text file that might have several hundred entries like the following:
ASIN: B00137RNIQ
-------------------------Status Info-------------------------
Upload created: 2010-04-09 09:33:45
Upload state: Imported
Upload state id: 3
I can parse the above with regular expressions and use the data to create new objects in a "Product" class:
class Product
attr_reader :asin, :creation_date, :upload_state, :upload_state_id
def initialize(asin, creation_date, upload_state, upload_state_id)
#asin = asin
#creation_date = creation_date
#upload_state = upload_state
#upload_state_id = upload_state_id
end
end
After parsing, the raw text from above will be stored in an object that look like this:
[#<Product:0x00000101006ef8 #asin="B00137RNIQ", #creation_date="2010-04-09 09:33:45 ", #upload_state="Imported ", #upload_state_id="3">]
How can I then interact with the newly created class objects? For example, how might I pull all the creation dates for objects with an upload_state_id of 3? I get the feeling I'm going to have to write class methods, but I'm a bit stuck on where to start.
You would need to store the Product objects in a collection. I'll use an array
product_collection = []
# keep adding parse products into the collection as many as they are
product_collection << parsed_product_obj
#next select the subset where upload_state_ud = 3
state_3_products = product_collection.select{|product| product.upload_state_id == 3}
attr reader is a declarative way of defining properties/attributes on your product class. So you can access each value as obj.attribute like I have done for upload_state_id above.
select selects the elements in the target collection, which meet a specific criteria. Each element is assigned to product, and if the criteria evaluates to true is placed in the output collection.
Related
I have:
a) given product_template_id (i.e. id 100) and
b) a duplicated product_template_id (i.e. id 200) created using copy() method
copy() method copies only product.template model, so suppliers for that specific product are not copied.
I would like to duplicate all suppliers for that model, but now I am wondering which is the right way to do it in Odoo.
If I understood the model properly suppliers prices for a given product are stored in product_supplierinfo table, where each record that points to a given product_tmpl_id specifices a supplier price/qty for a given product_template.
Which would be the way in Odoo to search for all records that point to a given product_tmpl_id (i.e. 100), duplicate them changing product_tmpl_id to the new one (i.e. 200)?
Excerpt from the ORM Documentation:
copy (bool) -- whether the field value should be copied when the record is duplicated (default: True for normal fields, False for One2many and computed fields, including property fields and related fields)
The field you're referring to is seller_ids, whose field definition is below:
seller_ids = fields.One2many('product.supplierinfo', 'product_tmpl_id', 'Vendors')
The copy attribute is not explicitly defined, so it is False by default (as explained in the documentation above). If you want this field to copy along with the other values during the standard product "Duplicate" (copy method), you can do this:
class ProductTemplate(models.Model):
_inherit = 'product.template'
# This only changes the copy attribute of the existing seller_ids field.
# All other attributes (string, comodel_name, etc.) remain as they are defined in core.
seller_ids = fields.One2many(copy=True)
Alternatively
If you want to only have the field copied sometimes, you can extend the copy method to look for a specific context value and only copy based on that.
# This may take some tweaking, but here's the general idea
#api.multi
def copy(self, vals):
new_product = super(YourClass, self).copy(vals)
if vals.get('copy_sellers'):
new_product.seller_ids = self.seller_ids.copy({'product_id': new_product.id})
return new_product
# Whatever you have calling the copy method will need to include copy_sellers in vals
vals.update({'copy_sellers': True})
product.copy(vals)
I am having a really weird problem while attempting to do a very simple thing. I am doing an .includes on a model to get a row of data from the database. On the return object I need to remove certain attributes conditionally. And the final aim is to reinsert this row as a new record based on the changes I make on the attributes using my conditions.
def myUpdate
dbObj = Obj.includes(:name,
:addr1,
:addr2,
:state,
:description).find(params[:id])
#dbObjective.attributes().except('description')
#dbObjective.description = nil
#dbObjective.attributes().delete('description')
# After setting more attributes, persist this object
end
I tried all possibilities that I could think of, but the attribute is just not getting removed. What am I missing? I am on Ruby on Rails 4.2.
includes is used to include associated tables in your query for join queries and eager loading, not for table attributes. You do not need to do anything special to access an object's attributes.
attributes returns a Hash instance containing the record's attributes as key-value pairs, and operating on it will change only the Hash instance itself, not the record.
There are several ways to update attributes. One of the easiest ways is using the built in setter methods given to you by ActiveRecord. If you really want to change attributes using the Hash API you can store the attributes hash in a variable, manipulate the hash, and pass it as an argument to update, which accepts an attributes hash as it's argument.
Using setter methods
def myUpdate
dbObj = Obj.find(params[:id])
dbObj.description = 'new_description'
dbObj.name = 'new_name
dbObj.save
end
Using update
def myUpdate
dbObj = Obj.find(params[:id])
attributes = dbObj.attributes # This is how you would update the object by manipulating the attributes hash
attributes.delete(:description) # this will NOT end up changing the attribute in the DB
attributes[:name] = nil # this will successfully set name to NULL in the DB
dbObj.update(attributes) # pass the manipulated hash to the `update` method to persist the changes
end
deleteing fields from the hash will not have an effect on the persisted object. update only performs an insert on fields present in the hash that have changed.
I have a set of legacy database tables that i cannot normalize out to what should have been done in the first place. e.g one big table with 200 columns.
I'm building an API and would like to represent this data to the consumer in a better state, and perhaps address the database issues at a later stage, there are many backend systems that reply on the data and changes are not easy.
I wanted to represent the current database schema using Active Record, however perform a model transformation into a new model that will be used for presentation only to an API consumer as json data.
current database schema:
Products table (200 columns)
New Model:
Product
+ Pricing
+ Assets
+ Locations
+ Supplier
I could hard-code a json string in a template, but feel that would not be a very poor approach.
What approach or gem would you recommend to tackle this best?
I have looked at :
RABL
ActiveModel::Serializers
If you define an as_json method that returns a hash, ActiveRecord will take care of the serialization for you. E.g.
class Product < ActiveRecord::Base
def as_json options = {}
{
product: <product value>,
pricing: <pricing value>,
# ... etc.
}
end
end
Now you can do:
> Product.first.to_json
=> "{\"product\":<product_value> ... }"
You can even render these as json from the controllers via:
render json: #model
For example, I have two models:
class Person(models.Model):
name = models.CharField(max_length=100)
class Job(models.Model):
title = models.CharField(max_length=100)
person = models.ForeignKey(Person)
I have a list of job ids--
job_ids = [1, 2, ....]
that are pks of Job model instances
I know I can do--
for id in job_ids:
person.jobs.add(job_id)
but this will be many more queries than if I could do--
person.jobs.add(job_ids)
where it would unpack the list and use bulk_create. How do I do this? Thanks.
Have you tried
person.jobs.add(*job_ids)
In my case I used a filter query and had a list of objects (as opposed to IDs). I was getting an error similar to
TypeError: 'MyModel' instance expected, got [<MyModel: MyModel Object>]
...before I included the asterisk.
credit (another SO question)
If you didn't create your jobs yet, you can create them by adding bulk=False
jobs_list=[
Job(title='job_1'),
Job(title='job_2')
[
person.jobs.add(*jobs_list, bulk=False) # your related_name should be 'jobs', otherwhise use 'job_sets'.
There are user and user_level models in our rails app. In user_level there is a field called user_group_id. The relationship is userhas_manyuser_levels. We would like to generate an array of the user_group_id (in user_level) for a given user_id.
For a given user_id, its user_levels could be retrieved as :
u = User.find(user_id)
ul = u.user_levels
There may be multiple user_levels for a user. How to create an array of user_group_id from ul with ruby map (or some other ruby method(preferable ruby))? thanks.
Try this,
user = User.find(user_id)
user.user_levels.pluck(:user_group_id)
or this,
user.user_levels.map(&:user_group_id)
The first makes a separate database query selecting just the :user_group_id. For example, in MySQL it would call SELECT user_levels.user_group_id ....
The second collects the :user_group_id from the fetched user_levels.
You are indeed looking for map
user_group_ids = ul.map{|x| x.user_group_id}
Or with the shorthand:
user_group_ids = ul.map(&:user_group_id)
You might also want to have only different ids and no nils
user_group_ids = ul.map(&:user_group_id).uniq.compact