Can we load multiple factories into the database in one shot? - ruby-on-rails-3

Just started using factory girl. If one has to save a factory into the db then one has to run
FactoryGirl.create().
But is there any way to load a collection of factories into the database without having to call create on each of the factories?
If its of any help i'm using Ruby 1.9.3, Rails 3.2.8 and Factory Girl 4.1.

If you need a bunch of factories of different type, you'll simply have to create them individually. You can make this a bit less verbose by adding this to your test_helper.rb:
include FactoryGirl::Syntax::Methods
Then you can create factories like this:
create(:factory_name)
And of course, if you need a bunch of records of the same type, you can create them like this:
5.times { create(:factory_name) }
As mentioned in my comment, creating all your factories in one fell swoop on initialization of your test framework is counter-productive. The idea behind FactoryGirl is to provide just the data you need for each test case or context. This avoids dependencies between tests that tend to slip into a fixture-driven approach.

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How to do Object–Relational mapping in ABAP?

I'm currently tring to port an application using hibernate to ABAP.
So short version is: I've (at least) two tables, let's say Entity(entity_id, ...) and SubEntity(sub_entity_id, entity_id).
Now in ABAP OO I'm representing these entities as classes, like zcl_app_entity. Now I'm wondering how I could use ABAP to persist these entities and relationships.
I've use-cases like:
Lock entity, and then add subentity
Get all subEntities and send them via http as json
In Java with JPA I'd do something like
Entity entity = userRepository.findById(entityId);
entity.lock(); // granted, this mechanism would on DB Level here while ABAP needs ABAP Locks
entity.getSubEntities.add(address);
There's a session with UnitOfWork automatically with the repository call. But as far as I'm aware ABAP doesn't offer a Repository pattern which automatically transforms classes to managed entities.
I could of course add INSERT etc directly into the add calls, or create a load / persist method on every class. But then I lose the testability.
I could create Repositories myself, passing in the objects. But then my Objects are repository aware itself (addAddress would call the repository).
Another way would be in the service class to call the repository, and then pass that object to the add method after it's persisted. Quite error prone.
Also lazy loading of e.g. xstrings (like 50MB) would be great, this won't work when the object has no access to the repository / sql interface to load on demand though.
I'd be super suprised if there isn't something like this (JPA/Hibernate), since these are common patterns.
IEntityRepository, ISubEntitiyRepository, IMyService (calls repo interfaces)
All calls make objects managed, maybe with OneToMany etc relationships, rollbacks, lazy load.
Weirdly I found the most ABAP way to have some logic in classes (e.g. the Entity->lock( ), entity->add_subentity( xyz ) but then just use an SQL persistency interface to get all data and return some structures. There wouldn't really be OO relationships. At most a class would be used as a short time driver of a struct. But when I'd say update all sub_entities it would be more like data_provider->get_sub_entity( entity_id ) which returns an internal table. And then the requestor has to persist it again if required data_provider->update_sub_entity_status( entity_id, 'R' )
So how do I use Object–Relational mapping in ABAP, e.g. when I want to update the status of all sub_entities of entitiy X to 'DONE' while keeping it testable?
You can take a look at the basic ABAP persistence service.
In se24 if you create a class, you can mark it as "persistent".
Eg SFLIGHT.
https://blogs.sap.com/2012/04/18/abap-persistent-object-services-demystified/#:~:text=The%20Persistence%20Object%20Services%20can,again%20when%20you%20need%20them.
There is an generated example on every system CL_SPFLI_PERSISTENT
If you have used ORMs in other languages like c# , this will be a very disappointing experience.
This toolset began around 20 yrs ago, but offers a questionable return on invest if you ask me.
Apart from the fact the approach doesnt conform to traditional OO principals.
When this first came out SAP already had 3GL code updating traditional
tables. Most developers even SAP internal, had no clear idea how to implement an ABAP OO model.
90% of the code SAP delivered didnt use this type of model. So there where no good examples to base your own work on.
Unfortunately it never took off and was never extended to have the functionality expected in a true ORM persistence tool.
I dont recall seeing anything inside the toolset that manages things like cascade delete. Nor A proper class relationship model?
Please correct me if I missed that.
If you ask me, sap generated a class with GET and SET methods and a PERSIST method and that was where it stopped.
Actually using Classes not DDIC structures as the model and implementing things like cascade delete look outstanding.
If you google SAP and ORM you will see a Javascript tool using Hibernate and HANA as the DB. Not an ABAP based tool.
or you will see ORM meaning Operational Risk Mgt.
That pretty much says it all. The ABAP layer has a toy Class generator but no true ORM tool like entity framework on .net.

One abstract rails model

In rails/activerecord, is it possible to have three ruby classes, two of which inherit from one main class, and then have two separate tables for pots and pans. Like so...
class Tupperware < ActiveRecord::Base
end
class Pot < Tupperware
end
class Pan < Tupperware
end
and the advantage would be that I could use the Tupperware.find() method, and a few other things, without having to customize for each different type.
I know for sure it works with mongoid – I've done it myself a couple of times. I'm not sure if this would work in relative database engine...
But you're actually asking a question you could answer yourself, by just trying to do what you said.
[In response to OP's comment]:
I'm just saying you should do a test rails application using a relative db, such as mySQL or SQLite and define your models exactly the way you think.
I have an abstract model I use in my application. It's working perfectly and the find() method works just as you'd expect, but I'm working on Mongoid, so I don't use ActiveResource and can't say for sure if this will work for you. The only thing you can do is try.
Here, take a look at this excerpt from my code:
https://gist.github.com/ellmo/5262681

Create a single, custom, globally available object in a rails app

I am having a very difficult time finding the answer to this. I want to create a custom class (this I know how to do) and have it get instantiated--one instance--that is globally accessible from within my application. I am looking to centralize and abstract some code and use this globally-available object as an interface. I can't believe how weird this is to figure out.
I need to have models, etc., available from within this object.
Help is appreciated.
I am running Rails 3.2.8.
Any model that you put in app/models will be autoloaded by Rails, so you can stick a custom model there.
The class will be available throughout your app, so whether you can just use class methods or not is up to you. If you want it to be a singleton, see this helpful article.
Lastly, if you need the model to instantiate in some specific way, just put it in an initializer. Any file in config/initializers will be run once as the app boots up.
You probably want a Singleton...
http://www.ruby-doc.org/stdlib-1.9.3/libdoc/singleton/rdoc/Singleton.html
However, that will only be available to that apps process. If you run multiple app servers (ie. multiple thin instances or Passenger) each will have it's own instance.
If you need something truly global you'll have to look into other options.

Model View Controller: Does the Controller or Model fetch data off the server?

For example: Let's say I'm grabbing a list of names and saving it to an NSMutableArray. Do I implement the method of actually calling the server to fetch the data in the controller (UIViewController) or the model(Friends object)?
It's a design decision that depends on what you're trying to accomplish. If your model only makes sense in the context of a single service, or if you want your model to provide access to all the data on the server, then build the connection to the server into your data model. This might make sense if you are, for example, building a client for a service like Twitter or Flickr.
On the other hand, if you're just grabbing a file from a server and that's the end of it, it may make sense to do the communication in the controller. Controllers tend to be less reusable and more customized for the particular behavior of the application. Keeping the specifics about where the data comes from out of the model makes the model more reusable. It also makes it easy to test -- you can write test code that just reads a local file and stores the data in the model.
That's a good question. I think the best way is through a controller because it decouples your model from requiring the other model to be present for it to work properly. Although I don't think you violate "proper mvc" by doing it in the model either.
I think you want to put it in the model. What you'll do is interrogate the model for the data and then the model will handle how to populate itself whether it's from an internal data store or an external one (like a server).
One approach is to use the repository pattern. To do this, you create Repository objects in your Model folder and you place all of you database-related methods in them. Your controllers call the repository classes to get the data. This allows you to separate the real model objects from the database accessing methods.
I use the MVCS pattern (Model-View-Controller-Store), which I discovered in Aaron Hillegass's book "IOS Programming: The Big Nerd Ranch Guide" (http://www.bignerdranch.com/book/ios_programming_the_big_nerd_ranch_guide_rd_edition_)
The store is specifically designed to fetch the data, whether it comes from a server, a local file, a persisted collection, a database, etc.
It allows to build very evolutive applications. For example, you can build your application based on a web service, and the day you want to persist your data, you juste have to modify the store, without having to modify a single line of code in your controller.
It's a lot like the Repository Pattern (http://msdn.microsoft.com/en-us/library/ff649690.aspx) (cf BobTurbo's answer)
I'd personally make a DAO, or data helper class. It's very hard to follow the strict MVC in objective C when things get more complicated. However, putting it in the model or the VC is not wrong as well.

When is it Appropriate to use Custom Classes in a Rails Application?

This is a complicated question with many possible answers, so I'll break down my situation into simple bullet points to help narrow down the solution:
My Rails App Has the Following 'Objects'
Author
Feed
Update
FeedTypes
The Objects are Related Like So:
Authors can have 1 or more Feeds
Feeds can have one or more Updates
A Feed has one feedType
Example Setup:
Author: Levi Hackwith
Feed: view-source:http://www.twitter.com/statuses/user_timeline/opnsrce.xml
FeedType: Twitter
Update: The tweets inside the Feed
My problem and My Questions:
Problem:
I need to parse the above-mentioned feed and store each tweet in the updates table. To parse the feed, I was thinking of writing a custom Feed class which would get inherited by TwitterFeed, FacebookFeed, TumblrFeed, etc.
However, I'm not sure if this is the 'Best Practice' for solving this kind of problem.
Questions:
When is it appropriate to develop a custom class to perform an action in RoR (as opposed to going through the Model or Controller)?
If this situation does not call for a custom class, which element should I apply the parsing logic to? The model or the controller?
If this is an appropriate situation for a custom class, where in my rails application should I store it (in other words, what's the right 'convention')?
You are probably going to have a background task invoked from time-to-time to check all the feeds, fetch new updates and store those in database. This task is completely separate from controllers and it should be possible to invoke it without any controller logic.
Your abstraction looks fine. You can further have something like XmlFeed < Feed if several feeds share a common XML structure.
1) Controllers should talk to database/models and pass relevant data to the view to render. Everything else should be either in a model, helper or library.
2) Are you asking where the parsing logic belongs to? In MVC, I think this would belong under the Model and/or a helper class, but definitely not the controller.. it's not its responsibility.
3) Classes holding data go into app/models. Classes that have nothing to do with holding data, go into the lib directory.
Don't shy away from using a custom class if it's appropriate. If you need another a class, then add one, the fact you are using rails is not relevant to that decision.