rails 单模型多态

As a beginner of Rails, I often get confused about what generator generates what and the syntax of these commands. Below is a cheat sheet on the four main generators I find most useful.

作为Rails的初学者，我经常对生成器生成什么内容以及这些命令的语法感到困惑。 以下是我发现最有用的四个主要生成器的备忘单。

这些是什么？ (What are they?)

They build out standard features of certain parts of your rails application. To start any generator type rails g or rails generator followed by your command.

它们构建了Rails应用程序某些部分的标准功能。 要启动任何生成器，请输入rails g或rails generator然后输入命令。

To find a list of all generators you can also type rails g. *make sure you are in your rails app*

要查找所有发电机的列表，您还可以输入rails g 。 *确保您在Rails应用中*

You will see a terminal output that resembles below. This article will focus on the bolded generators: controller, migration, model, and resource.

您将看到类似于以下的终端输出。 本文将重点介绍粗体生成器：控制器，迁移，模型和资源。

General options: -h, [--help] # Print generator's options and usage -p, [--pretend] # Run but do not make any changes -f, [--force] # Overwrite files that already exist -s, [--skip] # Skip files that already exist -q, [--quiet] # Suppress status outputPlease choose a generator below.Rails: application_record assets channelcontroller generator helper integration_test jbuilder job mailbox mailermigrationmodelresource scaffold scaffold_controller system_test taskActiveRecord: active_record:application_recordTestUnit: test_unit:channel test_unit:generator test_unit:mailbox test_unit:plugin

There are a lot more as you can see and you can easily learn about them by entering rails g <name of generator> in the terminal. Your terminal will output a short description of that generator.

您可以看到更多内容，并且可以在终端中输入rails g <name of generator>来轻松了解它们。 您的终端将输出该生成器的简短描述。

注意事项 (Things to note)

A lifesaver for me is that you can easily erase all traces of the generator you created by simply replacing the g in rails g <generator name> to a d like so, rails d <name of generator>. So don’t be afraid!

用于我的救星是，你可以很容易地通过简单地更换克删除您创建的发电机的所有痕迹rails g <generator name>到广告，像这样， rails d <name of generator> 。 所以不要害怕！

Also, note I added —-note-test-framework in the below examples, this does not create test files. If you need test files simply omit this command.

另外，请注意，我在以下示例中添加了—-note-test-framework ，这不会创建测试文件。 如果您需要测试文件，只需忽略此命令。

Lastly, since summer is almost over and who doesn’t like ice cream?! I chose ice cream as my generator example. Eat up!

最后，由于夏天快结束了，谁不喜欢冰淇淋？ 我选择冰淇淋作为发电机示例。 吃吧

移民 (Migration)

The migration generator makes it easy to create and edit tables. To create a migration table follow below. You can also add columns to your command. String is the default datatype, so flavor in the example below is the same as size:string.

迁移生成器使创建和编辑表变得容易。 要创建迁移表，请遵循以下步骤。 您也可以在命令中添加列。 String是默认数据类型，因此下面示例中的flavor与size：string相同。

rails g migration create_ice_creams flavor size:string scoops:integer

You will see the below output telling you your table was created!

您将看到以下输出，告诉您您的表已创建！

Running via Spring preloader in process 57527 invoke active_record create db/migrate/20200906130653_create_ice_creams.rb

If you go into your db/migrate folder you will see the table set up! Now all you need to do is rails db:migrate. Sweet!

如果进入db / migrate文件夹，您将看到表格已设置！ 现在您需要做的就是rails db:migrate 。 甜！

模型 (Model)

To create a model generator type the following in your terminal. Just like the migration generator, you can include attributes.

要创建模型生成器，请在终端中输入以下内容。 就像迁移生成器一样，您可以包含属性。

rails g model IceCream flavor size scoops:integer --no-test-framework

The below output tells us our migration table was created with the attributes along with our model file!

下面的输出告诉我们，迁移表是使用属性以及模型文件创建的！

Running via Spring preloader in process 77288 invoke active_record create db/migrate/20200908121113_create_ice_creams.rb create app/models/ice_cream.rb

控制者 (Controller)

For the controller generator instead of adding attributes like the model, you can add controller actions.

对于控制器生成器，您可以添加控制器操作，而不是添加模型之类的属性。

rails g controller ice_creams index show --no-test-framework

Your output will show that you just created quite a few files and folders!

您的输出将显示您刚刚创建了许多文件和文件夹！

Running via Spring preloader in process 58112 create app/controllers/ice_creams_controller.rb route get 'ice_creams/index'get 'ice_creams/show' invoke erb create app/views/ice_creams create app/views/ice_creams/index.html.erb create app/views/ice_creams/show.html.erb invoke helper create app/helpers/ice_creams_helper.rb invoke assets invoke scss create app/assets/stylesheets/ice_creams.scss

Let’s see what we created!

让我们看看我们创造了什么！

Our ice_creams_controller.rb with our index and show actions defined

我们的ice_creams_controller.rb及其索引并显示已定义的操作 Routes for index and show

索引和显示的路线 A folder in the views folder called ice_creams with index and show html.erb files

views文件夹中的一个名为ice_creams的文件夹，带有索引并显示html.erb文件 helper files

助手文件 stylesheets for the controller

控制器的样式表

资源资源 (Resource)

This is the most powerful out of the four! You can also include attributes for your model.

这是四个中最强大的！ 您还可以包括模型的属性。

rails g resource IceCream flavor size scoops:integer --no-test-framework

Your terminal output will look something like below

您的终端输出如下所示

Running via Spring preloader in process 61311 invoke active_record create db/migrate/20200906152644_create_ice_creams.rb create app/models/ice_cream.rb invoke controller create app/controllers/ice_creams_controller.rb invoke erb create app/views/ice_creams invoke helper create app/helpers/ice_creams_helper.rb invoke assets invoke scss create app/assets/stylesheets/ice_creams.scss invoke resource_route route resources :ice_creams

Here we created…

在这里，我们创建了……

Migration table along with columns that we put as our attributes

迁移表以及我们作为属性放置的列 The model

该模型 Controller with no actions

控制器无动作 Ice_creams folder in views (note: no action html.erb files)

视图中的Ice_creams文件夹(注意：无操作html.erb文件) Helper files

助手文件 Stylesheets for the controller

控制器的样式表 Resource Route for all CRUD actions

所有CRUD动作的资源路线

As you can see rails generators are very powerful and can save a lot of time if you know how to utilize them. Hope this helped and happy coding!

如您所见，rails生成器非常强大，如果您知道如何使用它们，则可以节省很多时间。 希望这对您有所帮助并且编码愉快！

翻译自: https://medium.com/@samantha.lurio/rails-generators-cheat-sheet-61e2e58b7be7

rails 单模型多态

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