Question

我使用Ruby on Rails并遇到了一个问题，我需要向JSON渲染MySQL查询。我已尝试Google解决此问题并找到了as_json方法，但该方法并不完全有效。 as_json方法不会呈现子对象，即使我尝试在单独的调用中呈现sub_object（IE @item[:sub_item] = item.sub_item.as_json仍然会在到达视图时导致sub_item为nil）

@initial_posts.push({
    :attempted => post.attempted,
    :body => post.body,
    :correct => post.correct,
    :course_id => post.course_id,
    :created_at => post.created_at,
    :entity_type => post.entity_type,
    :file => post.file,
    :flagged => post.flagged,
    :global => post.global,
    :id => post.id,
    :incorrect => post.incorrect,
    :is_link => post.is_link,
    :removed => post.removed,
    :subscribed => post.subscribed,
    :title => post.title,
    :updated_at => post.updated_at,
    :upvotes => post.upvotes,
    :user_id => post.user_id,
    :uuid => post.uuid,
    :views => post.views,
    :voted => post.voted,
    :comment => [],
    :quiz_choice => [],

    :user => {
        :UUID => post.user.UUID,
        :account_type => post.user.account_type,
        :created_at => post.user.created_at,
        :email => post.user.email,
        :first_name => post.user.first_name,
        :id => post.user.id,
        :image => post.user.image,
        :image_content_type => post.user.image_content_type,
        :image_file_name => post.user.image_file_name,
        :image_file_size => post.user.image_file_size,
        :image_updated_at => post.user.image_updated_at,
        :last_name => post.user.last_name,
        :picture => post.user.picture,
        :rank => post.user.rank,
        :reputation => post.user.reputation,
        :updated_at => post.user.updated_at,
        :upvotes => post.user.upvotes,
        :username => post.user.username
    }
})

post.comment.each do |comment|
    @initial_posts.last[:comment].push({
        :comment => comment.comment,
        :course_id => comment.course_id,
        :created_at => comment.created_at,
        :id => comment.id,
        :post_id => comment.post_id,
        :updated_at => comment.updated_at,
        :upvote => comment.upvote,
        :user_id => comment.user_id,

        :user => {
            :UUID => comment.user.UUID,
            :account_type => comment.user.account_type,
            :created_at => comment.user.created_at,
            :email => comment.user.email,
            :first_name => comment.user.first_name,
            :id => comment.user.id,
            :image => comment.user.image,
            :image_content_type => comment.user.image_content_type,
            :image_file_name => comment.user.image_file_name,
            :image_file_size => comment.user.image_file_size,
            :image_updated_at => comment.user.image_updated_at,
            :last_name => comment.user.last_name,
            :picture => comment.user.picture,
            :rank => comment.user.rank,
            :reputation => comment.user.reputation,
            :updated_at => comment.user.updated_at,
            :upvotes => comment.user.upvotes,
            :username => comment.user.username
        }
    })
end

post.quiz_choice.each do |quiz_choice|
    @initial_posts.last[:quiz_choice].push({
        :choice => quiz_choice.choice,
        :created_at => quiz_choice.created_at,
        :id => quiz_choice.id,
        :is_answer => quiz_choice.is_answer,
        :post_id => quiz_choice.post_id,
        :updated_at => quiz_choice.updated_at
    })
end

如果模型或迁移在任何时候发生变化，这显然会成为一个问题。我怎么能用更少，希望更便携的代码来写这个呢？

Answer 1

如果我正确理解了您的问题，我认为to_json是您正在寻找的方法。这种方法也可以渲染相关对象，例如：

item.to_json(include: :sub_items)

它将生成：

{ id: item_id, attr1: item_attr1_value, sub_items: [{ id: 2, attr2: value2, ... }, ...]

表达此代码的简单方法是什么？

1 个答案: