Rails 4：链接缩略图错误的 URI 格式答案

【问题标题】：Rails 4: Link Thumbnailer Bad URI formatRails 4：链接缩略图错误的 URI 格式
【发布时间】：2016-10-11 21:07:48
【问题描述】：

我正在尝试使用 Link Thumbnailer 从食谱网站获取标题、图像和描述，但由于某种原因，当我提供网站的 URL 时，我不断收到 BadUriFormat 错误。

在我看来，我有：

<% @recipes.each do |recipe| %>

  <tr>
    <td class="recipe-info">
        <%= image_tag LinkThumbnailer.generate(recipe.image_link).images.first.src.to_s %>
    </td>
  </tr>

...这个例子中的配方是：

#<Recipe:0x007fe48394a358> {
    :id => 1,
    :name => "test",
    :image_link => "http://paleoleap.com/simple-beef-shish-kabobs/"
}

这是我的错误：

ETHON: started MULTI
ETHON:         performed EASY effective_url=http://res.cloudinary.com/paleoleap/image/upload/f_auto,q_90/v1459886762/j-paleo/simple-beef-shish-kabob-main.jpg response_code=200 return_code=write_error total_time=0.04831799999999997
ETHON: performed MULTI
ETHON: started MULTI
ETHON:         performed EASY effective_url=http://paleoleap.com/pictures/icons/servings.png response_code=200 return_code=write_error total_time=0.053881
ETHON: performed MULTI
ETHON: started MULTI
ETHON:         performed EASY effective_url=http://paleoleap.com/pictures/icons/prep3.png response_code=200 return_code=write_error total_time=0.050677
ETHON: performed MULTI
ETHON: started MULTI
ETHON:         performed EASY effective_url=http://paleoleap.com/pictures/icons/cooking4.png response_code=200 return_code=write_error total_time=0.044727
ETHON: performed MULTI
ETHON: started MULTI
ETHON:         performed EASY effective_url=http://res.cloudinary.com/paleoleap/image/upload/f_auto,q_90/v1459886762/j-paleo/simple-beef-shish-kabob-preparation.jpg response_code=200 return_code=write_error total_time=0.048975
ETHON: performed MULTI
  Rendered recipes/index.html.erb within layouts/application (510.5ms)
Completed 500 Internal Server Error in 1040ms (ActiveRecord: 7.3ms)

LinkThumbnailer::BadUriFormat (LinkThumbnailer::BadUriFormat):
  app/views/recipes/index.html.erb:46:in `block in _app_views_recipes_index_html_erb___148801017206438179_70110103402900'
  app/views/recipes/index.html.erb:26:in `_app_views_recipes_index_html_erb___148801017206438179_70110103402900'

当我通过执行LinkThumbnailer.generate(Recipe.find(1)) 在控制器中获取图像时，它运行没有问题。

这里是成功的：

ETHON: started MULTI
ETHON:         performed EASY effective_url=http://res.cloudinary.com/paleoleap/image/upload/f_auto,q_90/v1459886762/j-paleo/simple-beef-shish-kabob-main.jpg response_code=200 return_code=write_error total_time=0.056864
ETHON: performed MULTI
ETHON: started MULTI
ETHON:         performed EASY effective_url=http://paleoleap.com/pictures/icons/servings.png response_code=200 return_code=write_error total_time=0.04847
ETHON: performed MULTI
ETHON: started MULTI
ETHON:         performed EASY effective_url=http://paleoleap.com/pictures/icons/prep3.png response_code=200 return_code=write_error total_time=0.04541
ETHON: performed MULTI
ETHON: started MULTI
ETHON:         performed EASY effective_url=http://paleoleap.com/pictures/icons/cooking4.png response_code=200 return_code=write_error total_time=0.039456
ETHON: performed MULTI
ETHON: started MULTI
ETHON:         performed EASY effective_url=http://res.cloudinary.com/paleoleap/image/upload/f_auto,q_90/v1459886762/j-paleo/simple-beef-shish-kabob-preparation.jpg response_code=200 return_code=write_error total_time=0.0386
ETHON: performed MULTI

在我的循环中对recipe.image_link 调用generate 方法与在控制器中的特定Recipe 上调用它有什么区别？

【问题讨论】：

我看到你正在循环@recipes 的数组，你能显示那个数组的值吗？我怀疑您的数组中有一个空白值会触发BadUriFormat 异常
天哪。我有一种感觉，这很愚蠢。我的第二个recipe 没有:image_link。

标签： ruby-on-rails ruby-on-rails-4 url uri

【解决方案1】：

写下我的评论作为答案。您的 @recipes 数组必须包含一个空白值，这会导致 gem 引发 BadUriFormat 异常。

此外，我建议以下选项以避免 gem 在获取网站时进行不必要的计算：

LinkThumbnailer.generate(url, attributes: [:images], image_limit: 1, image_stats: false)

attributes -- 会告诉 gem 只关心图片
image_limit -- 会告诉 gem 只获取一张图片。但是，它可能不是最好的，因为它不会尝试获取多个图像。
image_stats -- 告诉 gem 不要关心图片的大小和类型

【讨论】：