One of the things that bothers me in Rails is that scaffolding generates migrations that I don't always need.
Is there a way to generate the scaffold without the corresponding migration?
Use the --skip-migration parameter. For example:
rails generate scaffold post title:string body:text --skip-migration
Related
I'm getting this error message when I run the above code generator: (I'm just a beginner)
invoke active_record
Another migration is already named create_posts.....
Use --force to remove the old migration file
What do I type into the terminal window to "use force"
You are getting the following error because you already have a migration named create_posts in your rails application.
invoke active_record Another migration is already named create_posts..... Use --force to remove the old migration file
So, what you need here is first remove the existing migration and then generate the scaffold.
rails d migration create_posts
rails generate scaffold post title:string body:text
Or
You could generate the scaffold using --force option
rails generate scaffold post title:string body:text --force
EDIT
As per your comment:
I did that and then a whole bunch of code appears with the lines of
code sating invoke...exist...identical.
It means that you already ran a scaffold once for Post successfully and you are trying to generate the scaffold again.
I am not sure why you are doing that BUT identical is not an error. Its just that Rails is telling you that you already have a particular file so I am not creating again.
You can reset your database if you don't care about losing your database with this :
b rake db:reset
This will re-reun all your migrations. But take note! Your migrations should be able to run from one end to the other. So if something is "not working" with the regular rake db:migrate, then you should resolve that issue is specifically.
Show me a more descriptive error, and I can tell you more.
You should add other migration in order to change your Post table as you want it to be.
Your could begin with rails g migration and see the help provided.
If you want to get away with it you can delete the migration that created the Post table (but I guess you would need to delete the DB)
After the first time you generate a scaffold, by default Rails will not overwrite the existing scaffold. This is to ensure that you don't accidentally destroy a lot of work.
If you're really sure you want to regenerate the scaffold and delete any changes you might have made to any of the generated files, try:
rails generate scaffold post title:string body:text --force
I am new to Ruby on Rails . This might be a very foolish question.
I have created a migration using
rails generate migration Kapol name:string position:integer
rake db:migrate
Then using phpmyadmin i copied the database already present
I then opened up rails console
My question is can i use the method Kapol.find(1)??
because when i tried it using singular or plural it says
unitialized constant:Kapol
I know that there has to be a method but where to specify it?
You must generate a model in case to create a table for it, because the migration is usually used to modify existing tables.
It might be confusing that the model generator also creates migration file in your migrations folder. The only difference is that the model generator also generates initial code to create table, on the other hand, the migration generator creates only migration file without initial code.
rails generate model Kapol name:string position:integer
More information: http://guides.rubyonrails.org/getting_started.html#generating-a-model
If you're very new to Ruby on Rails, probably the best thing for you to do is create a scaffold, which gives you your migration file, your model file, your controller file, and various view files, test files, etc. etc., which all work well together. Then you can play with these and build up from there.
rails generate scaffold Kapol name:string position:integer
If you're happy with the migration that was automatically generated, then rake db:migrate and you're all set.
As Andrew says below, you can also just generate any of those files one at a time by replacing 'scaffold' with 'model', etc.
Your Kapol.find(1) is correct.
I'm new to Rails so my current project is in a weird state.
One of the first things I generated was a "Movie" model. I then started defining it in more detail, added a few methods, etc.
I now realize I should have generated it with rails generate scaffold to hook up things like the routing, views, controller, etc.
I tried to generate the scaffolding but I got an error saying a migration file with the same name already exists.
What's the best way for me to create scaffolding for my "Movie" now? (using rails 3)
TL;DR: rails g scaffold_controller <name>
Even though you already have a model, you can still generate the necessary controller and migration files by using the rails generate option. If you run rails generate -h you can see all of the options available to you.
Rails:
controller
generator
helper
integration_test
mailer
migration
model
observer
performance_test
plugin
resource
scaffold
scaffold_controller
session_migration
stylesheets
If you'd like to generate a controller scaffold for your model, see scaffold_controller. Just for clarity, here's the description on that:
Stubs out a scaffolded controller and its views. Pass the model name,
either CamelCased or under_scored, and a list of views as arguments.
The controller name is retrieved as a pluralized version of the model
name.
To create a controller within a module, specify the model name as a
path like 'parent_module/controller_name'.
This generates a controller class in app/controllers and invokes helper,
template engine and test framework generators.
To create your resource, you'd use the resource generator, and to create a migration, you can also see the migration generator (see, there's a pattern to all of this madness). These provide options to create the missing files to build a resource. Alternatively you can just run rails generate scaffold with the --skip option to skip any files which exist :)
I recommend spending some time looking at the options inside of the generators. They're something I don't feel are documented extremely well in books and such, but they're very handy.
Great answer by Lee Jarvis, this is just the command e.g; we already have an existing model called User:
rails g scaffold_controller User
For the ones starting a rails app with existing database there is a cool gem called schema_to_scaffold to generate a scaffold script.
it outputs:
rails g scaffold users fname:string lname:string bdate:date email:string encrypted_password:string
from your schema.rb our your renamed schema.rb. Check it
In Rails 5, you can still run
$rails generate scaffold movie --skip
to create all the missing scaffold files or
rails generate scaffold_controller Movie
to create the controller and view only.
For a better explanation check out rails scaffold
This command should do the trick:
$ rails g scaffold movie --skip
You can make use of scaffold_controller and remember to pass the attributes of the model, or scaffold will be generated without the attributes.
rails g scaffold_controller User name email
# or
rails g scaffold_controller User name:string email:string
This command will generate following files:
create app/controllers/users_controller.rb
invoke haml
create app/views/users
create app/views/users/index.html.haml
create app/views/users/edit.html.haml
create app/views/users/show.html.haml
create app/views/users/new.html.haml
create app/views/users/_form.html.haml
invoke test_unit
create test/controllers/users_controller_test.rb
invoke helper
create app/helpers/users_helper.rb
invoke test_unit
invoke jbuilder
create app/views/users/index.json.jbuilder
create app/views/users/show.json.jbuilder
I had this challenge when working on a Rails 6 API application in Ubuntu 20.04.
I had already existing models, and I needed to generate corresponding controllers for the models and also add their allowed attributes in the controller params.
Here's how I did it:
I used the rails generate scaffold_controller to get it done.
I simply ran the following commands:
rails generate scaffold_controller School name:string logo:json motto:text address:text
rails generate scaffold_controller Program name:string logo:json school:references
This generated the corresponding controllers for the models and also added their allowed attributes in the controller params, including the foreign key attributes.
create app/controllers/schools_controller.rb
invoke test_unit
create test/controllers/schools_controller_test.rb
create app/controllers/programs_controller.rb
invoke test_unit
create test/controllers/programs_controller_test.rb
That's all.
I hope this helps
I want to generate the scaffold in a Rails app, generating the model as usual but having the controller inside the admin namespace. Is it possible?
The first time I've done it, I run
script/generate scaffold blog
and then refactored the controller, views, etc. My prefered solution at the moment is:
script/generate scaffold admin::blog
and then refactor the model, unit test and migration; it's less work.
If there's a better answer, I'll accept it.
You can do this for rails < 3:
script/generate scaffold Blog title:string
or
script/generate scaffold admin::blog title:string
For rails > 3:
rails g scaffold Blog title:string
or
rails g scaffold admin/blog title:string
This question is pretty widely asked on stackoverflow. And I also faced this problem and found no standard solution for that.
So, I created rails-admin-scaffold gem (for now it's Rails 4 only) which automates this process and wrote an article with more detailed explanation. Hope it would be helpful for someone.
For Rails 6:
assuming you have a model like:
rails g model Foo name:string
then you can do this with
rails g scaffold_controller Admin/Foo name:string --model-name="Foo"
(specifying the model name stops the controller from referring to the model Admin::Foo which would be the default)
NB: this isn't perfect; You'll have to fix up a bunch of path errors in your views and tests - but it gets you 80% of the way there.
I need to use the nifty_scaffold to generate all the views and controller for my model, but I already have the model, the migration and the table in database, so I don't need it to generate the migrations. The problem is that when it founds an old migration, it says
Another migration is already named your_table: db/migrate/20090904212205_create_your_table.rb
and I can't create the whole scaffold.
Is there any way to ignore migrations on scaffolding in Rails?
script/generate nifty-scaffold MyModel --skip-migration
should work.
Since you already have the model, you can pass the --skip-model parameter. As shown in the railscast tutorial, try this:
script/generate nifty_scaffold user_session --skip-model username:string password:string new destroy