这些奇怪的人物是什么意思? [英] What do these weird characters mean?

问题描述

我正在阅读一本Ruby书，但没有解释以下内容:

I'm reading a Ruby book but it doesn't explain the following:

1. 这是什么:validates :name, :presence => true

• 我的意思是我知道它的作用，但是validates是什么?它是验证器类的方法吗?如果是这样，怎么调用它而不先提到类名?

• I mean I know what it does but what's validates? Is it a method of the validator class? If so, how come it's called without mentioning the class name first?

:在先前的代码中以及一般的Rails中是什么意思?

What's the meaning of : in the previous code and in Rails on general?

在以下代码中:<%= form_for([@post, @post.comments.build]) do |f| %>

• form_for是对象还是过程函数?

• Is form_for an object or a procedural function?

|f|

在<%= link_to 'Edit Post', edit_post_path(@post) %>

• edit_post_path方法的定义对象是谁?何时何地定义?

• Who, where and when was edit_post_path method defined?

它属于哪个类?

推荐答案

1. validates是一种方法，属于

1. validates is a method, part of the validators in Rails. It is declared in (actually, included to) a superclass, that is why it does not have to be declared in the model. The : in front of anything signifies a symbol, not a variable. Symbols are part of Ruby, somewhat similar to strings.
2. form_for is a method, which takes a number of parameters and a block (that is why there is a do afterwards). The | is part of Ruby syntax, the way you enclose code block parameters.
3. edit_post_path is defined by the Rails magic and the routes. It is a helper method.

我鼓励您阅读这本书有关Ruby的知识，以更熟悉符号，代码块，模块和其他使Ruby成为出色的编程语言的东西.

I encourage you to read this book about Ruby to get more familiar with symbols, code blocks, modules and other things that make Ruby a great programming language.

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