ruby | 易学教程

Why rbenv does not work on Mac OS Catalina

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问题 I'm trying to run a Ruby on Rails project which has the version 2.4.1 and my system is 2.6.x . What I did was install via Rbenv the old version of Ruby then I did the following commands: rbenv global 2.4.1 -> to change global Ruby version ruby -v ruby 2.6.5p114 rbenv global 2.4.1 So there is something wrong as I would like to use 2.4.1 but seems not working that. I'm unable to start the bundle as it is saying I don't have 2.4.1 installed. I need a solution to Mac OS Catalina as I did as I

Why rbenv does not work on Mac OS Catalina

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How can I remove https and http from ruby on rails

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问题 I need to remove the "https" and the "http" from a url from my form in order to show the image later, I got the form where i'm including title and url like this: Form: <%= form_for( @article, :html => { class: "form-test", role: "form"}) do |f| %> <%= f.label :Titulo %> <%= f.text_field :title%> <%= f.label :Imagen%> <%= f.text_field :img%> <%= f.submit "Post"%> <% end %> View: <div class="header"> <%= image_tag("https://#{@article.img}") %> <%= @article.title%> </div> I'am looking for option

How do I assign multiple symbols to the same value in Ruby?

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问题 The idea of what I am trying to do is to clump synonym symbols to the same value, without having to redefine the same value over and over. Basically turn this: fruits = { orange: "Citrus", grapefruit: "Citrus", tangerine: "Citrus" } Into this: fruits = { orange:, grapefruit:, tangerine: => "Citrus" } What is the proper syntax for accomplishing this? Thanks 回答1: Use a hash, in order to access the type of fruit using the fruit name. For example: fruits = %i{ orange grapefruit tangerine apple }

Ruby && and = operators misudnerstanding

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问题 What do you think would be the result of the next expression in Ruby? a = 10 && b = 25 Try to calculate in the ming and only then use irb . So, if we take a look at the Ruby documentation about Operators Precedence then we will se that && operator has a higher priority than = . So you must think that Ruby will evaluate the expression in the next way: a = ((10 && b) = 25) But Ruby does a job in another way: a = (10 && (b = 25)) # => 25 So, the priority of the = in b = 25 is higher, then && .

如何在Python中创建天气警报系统

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前言通过阅读这篇文章，你将学会用Python创建一个天气警报系统，当它预测未来几小时内天空将下雨/下雪时，它会向多个收件人发送一封电子邮件通知。电子邮件通知包含其他信息，如预测的温度和湿度。本教程有3个部分: 1.设置 2.实现 3.结果设置天气API 我们将使用ClimaCell的天气API来获取预报天气数据。根据您的需要，它提供了相当多的有用和准确的数据。它涵盖了4周以前的历史站点数据以及15天以前的每日预报数据。此外，你可以很容易地实现它的官方文件提供参考4种不同的计算机语言: JavaScript Ruby Node Python 前往注册和注册一个新帐户。一旦完成，您应该会看到下面的指示板，它概述了计划细节和您的调用活动。请注意API键，因为我们将在后面的代码中使用它。邮件配置我将使用个人Gmail账号通过SMTP给自己发邮件。为了使用它，你需要改变帐户设置的配置，并打开不太安全的应用程序访问。转到帐户设置，然后点击安全菜单。打开不太安全的应用访问，如下所示完成之后，在项目的根目录中创建一个名为config.ini的新文件。它将被用作我们项目的配置文件。将以下代码添加到其中。 [email] email =your_email@gmail.com host =smtp.gmail.com port = 587 password =your

Rails Jquery compute total from selected checkboxes in a table

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问题 So here is my rails view which has a form which pulls the product_items and lets the user check all the items they want to buy and display the total order amount underneath the table. (attached pic) My code looks like below. The server side is good (where I can save the order) but I need some help on the client side js to compute the order total and displaying the order total underneath the table. <tbody> <% @cause.product.product_items.each do |item| %> <tr> <td width="60%"><label class=

Rails Jquery compute total from selected checkboxes in a table

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Ruby method lookup in regards to globals/scopes

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问题 I am trying to get a full understanding of how Ruby locates methods/symbols but am struggling when it involves multiple levels, especially the global/file scope. When calling methods explicitly on a class, there are lots of illustrations on the order in which the classes, and modules included by them are searched (and thus exactly what super calls in each case). But when not explicitly calling a method, e.g. a plain func args rather than self.func args what is the search order? Why does in my

How to use let variables in rails console?

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问题 using rspec 2.6.4 rails 3.1.6 How to use let variables in rails test console? 1.9.3-p0 :032 > let(:user) { create(:user) } NoMethodError: undefined method `let' for main:Object Please advise, which library should be required here? For example: below is executed in console to use stub methods in console. require 'rspec/mocks/standalone' Is it possible, to define and call let variables in rails console? 回答1: If you are fine with let just creating globals, you can polyfill it like this: def let