小编Sta*_*erd的帖子

我使用当前版本的 react-boilerplate（使用 webpack）并安装了 Semantic-UI-React，如官方文档http://react.semantic-ui.com/usage 中所述

当我启动服务器时，我得到：

Server started ! ?

Access URLs:
-----------------------------------
Localhost: http://localhost:3000
      LAN: http://192.168.100.103:3000
-----------------------------------
Press CTRL-C to stop

webpack built dba595efb772df0727e8 in 11657ms

ERROR in ./semantic/dist/semantic.min.css
Module parse failed: /Users/standardnerd/development/template/semantic/dist/semantic.min.css Unexpected character '@' (11:0)
You may need an appropriate loader to handle this file type.
|  *
|  */
| @import url(https://fonts.googleapis.com/css?family=Lato:400,700,400italic,700italic&subset=latin);/*!
|  * # Semantic UI 2.2.7 - Reset
|  * http://github.com/semantic-org/semantic-ui/
 @ ./app/app.js 20:0-43
 @ multi main

我需要什么样的“合适的装载机”？

解析器不喜欢 /semantic/dist/semantic.min.css 中的 @import 语句： …

我已经尝试过其他几个类似的帖子,但我仍然收到错误.

在Posts模型中,我有一个category_id字段.我有以下型号:

#Posts model
belongs_to :categories  

#Category model
has_many :posts

在Posts索引控制器中,我有:

@categories = @posts.Category.find(:all, :order => 'categoryname')

在视图我有:

<% @posts.each do |post| %>
<tr>
<td><%= post.category_id %></td>
<td><%= @categories.categoryname %></td>

<td><%= link_to 'View', post %></td>
<td><%= link_to 'Edit', edit_post_path(post) %></td>
</tr>
<% end %>

在第二列中,我尝试显示Category表中的类别名称("categoryname"),而不是posts表中的category_id.我收到一个错误:

#ActiveRecord :: Relation:0x3e1a9b0>的未定义方法`Category'

我也尝试过:

<td><%= post.categories.categoryname %></td>

但得到同样的错误.

以及:

<td><%= post.category.categoryname %></td>

任何建议将不胜感激.

如何检查数组的元素是否仅包含数字（整数）？

 describe "#draw" do
   it "returns an array" do
     expect(@lottery_tip.draw).to be_a_kind_of Array
   end
   it "has six elements" do
     expect(@lottery_tip.draw.count).to eq(6)
   end
   it "s elements are only numbers" do
     expect(@lottery_tip.draw).to ???
   end
 end

我的简单 LotteryTip 类有效，但我想知道如何检查返回数组中元素的类型...

我将Rails 4与Rails-i18n Gem一起使用,我想用我的语言翻译文件中的占位符替换我的硬编码字符串"300px",如config/locales/de.yml中的%{minimum_resolution}

  activerecord:
    errors:
      models:
        organisation:
          attributes:
            image:                 
              resolution_too_small:"Image Resolution should be at least %{minimum_resolution}"

%{minimum_resolution}中的值应来自app/models/organisation.rb中的自定义验证

  def validate_minimum_image_dimensions
    if image.present?
      logo = MiniMagick::Image.open(image.path)
      minimum_resolution = 300
      unless logo[:width] > minimum_resolution || logo[:height] > minimum_resolution
        errors.add :image, :minimum_image_size
      end
    else
      return false
    end
  end

如何从minimum_resolution获取值到我的yaml文件中？

我需要在我的HAML代码中使用这种结构:

- if @organisation.type == 'Company'
%p
  %strong Number of Employees:
  = @organisation.number_of_employees
- elsif @organisation.type == 'EducationalInstitution'
%p
  %strong Number of Students
  = @organisation.number_of_students

但我得到一个语法错误:得到"elsif"没有前面的"如果"我如何更新我的代码来解决错误？

我有一个PagesController指定了布局'pages.html.erb'.

  class PagesController < Spree::StoreController
    layout 'pages'
    respond_to :html

    def lifestyle
      render 'lifestyle'
    end

    def co_step_1
      render 'co_step_1'
    end

    def co_step_2
      render 'co_step_2'
    end

  end

是否可以在PagesController中使用另一种使用不同布局的方法？换句话说,我想覆盖layout 'pages.html.erb'另一种方法.

为什么普通Javascript的这个简单示例减少不起作用？

// expected output: ["red", "yellow", "blue"]
var primaryColors = [
  { color: 'red' },
  { color: 'yellow' },
  { color: 'blue' }
];

primaryColors.reduce({
  function(previous, primaryColor) {
    previous.push(primaryColor.color);
    return previous;
  }
}, []); 
// VM607:2 Uncaught TypeError: #<Object> is not a function
// at Array.reduce (native)
// at <anonymous>:2:15

作为练习,我正在尝试将地图示例转换为使用reduce:

const numbers = [1, 2, 3, 4];

numbers.map(function(a,b) {
    return a+b;
});
// [1, 3, 5, 7]

我尝试使用reduce的相同示例:

numbers.reduce(
  (sum, elem) => {
    sum.push(elem + elem); // how can one add the index of array to the number instead of doubling it?
    return sum;
  }, []);
// [2, 4, 6, 8], instead I want: [1, 3, 5, 7]

我有一个包含一个或多个对象的数组，我想过滤掉所有null属性：

asset = [{"ObjId":177791,"ObjCreditlineM":"DEU","ObjReprorechtM":null,"ObjKommentarM":null,"ObjZustandM":null,"ObjReserve01M":null,"ObjReserve02M":null,"ObjFeld01M":null,"ObjFeld02M":null,"ObjFeld03M":null,"ObjFeld04M":"Foto","ObjFeld05M":null,"ObjFeld06M":null,"ObjFeld07M":null,"ObjFeld01S":null,"ObjFeld02S":null,"ObjFeld03S":null,"ObjFeld04S":null,"ObjFeld05S":null,"ObjFeld06S":null,"ObjFeld07S":null,"ObjFeld01F":0,"ObjFeld02F":0,"ObjFeld01D":null,"ObjFeld02D":null,"ObjInv01S":null,"ObjInv02S":null,"ObjInv03S":null,"ObjInv04S":null,"ObjInv05S":null,"ObjInv06S":null,"ObjDinId":0,"ObjReferenz01Id":null,"ObjReferenz02Id":null,"ObjTransferId":null,"ObjGesperrtS":null,"ObjIconTextM":null}]


// My attempt:

var filledProps = asset.map(el => { 
  if (Object.keys(el)) { // check if object property value is not null
    return el;
  };
});

console.log(filledProps);

但是我又得到了相同的对象属性。我想念什么？

我有一个React组件帖子:

import React, { Component } from 'react';

const list = [
  {
    title: 'React',
    url: 'https://facebook.github.io/react',
    author: 'Adam Beat',
    num_comments: 4,
    points: 3,
    objectID: 10,
  }, {
    title: 'Rails',
    url: 'https://www.rubyonrails.org',
    author: 'DHH',
    num_comments: 8,
    points: 4,
    objectID: 11,
  }
]

class Posts extends Component {

  constructor(props) {
    super(props); // call the constructor of the extended class
    this.state = { // bound state with the this object
      list: list,
    };
    this.onDismiss = this.onDismiss.bind(this);
  }

  onDismiss(id) {
    // const isNotId …