[英]Undefined method 'map' when trying to create 'tags'
我正在重新使用本指南https://rubyplus.com/articles/4241-Tagging-from-Scratch-in-Rails-5,以允許我將'tastingsnotes'作為'roast.rb'模型上的標簽。
但是,當我試圖在瀏覽器中顯示記錄時,我得到錯誤undefined method 'map'
。 我很確定這不是我不能以某種方式正確映射標簽。 我可以看到當我嘗試編輯記錄時,我在那里有標簽。
邏輯是我有一個名為'Roasts'的模型我希望用戶能夠添加以逗號分隔的品嘗筆記列表。 因此,我將這些視為標簽。
roast.rb
class Roast < ApplicationRecord
has_many :tastings
has_many :notes, through: :tastings
def self.tagged_with(name)
Note.find_by!(name: name).roasts
end
def self.note_counts
Note.select('notes.*, count(tastings.note_id) as count').joins(:tastings).group('tastings.note_id')
end
def tastingnotes
notes.map(&:name).join(', ')
end
def tastingnotes=(names)
self.notes = names.split(',').map do |n|
Note.where(name: n.strip).first_or_create!
end
end
end
note.rb
class Note < ApplicationRecord
has_many :tastings
has_many :roasts, through: :tastings
end
tasting.rb
class Tasting < ApplicationRecord
belongs_to :note
belongs_to :roast
end
烤肉/ _form.html.rb
//items not pasted for brevity
<div class="form-group">
<%= form.label :tastingnotes, "Notes (separated by commas)", class: 'control-label' %><br />
<%= form.text_area :tastingnotes, id: :roast_tastingnotes, class: "form-control" %>
</div>
//items not pasted for brevity
烤肉/ show.html.rb
//items not pasted for brevity
<p>
<strong>Tasting Notes</strong>
<%= raw @roast.tastingnotes.map(&:name).map { |t| link_to t, tastingnotes_path(t) }.join(', ') %>
</p>
//items not pasted for brevity
控制台錯誤:
Completed 500 Internal Server Error in 18ms (ActiveRecord: 1.1ms)
ActionView::Template::Error (undefined method `map' for "chocolate, citrus":String
Did you mean? tap):
39:
40: <p>
41: <strong>Tasting Notes</strong>
42: <%= raw @roast.tastingnotes.map(&:name).map { |t| link_to t, tastingnotes_path(t) }.join(', ') %>
43: </p>
44:
45:
你做到了
def tastingnotes
notes.map(&:name).join(', ')
end
返回逗號分隔符串如“choco,beer”
現在你確實映射到下面的字符串
<%= raw @roast.tastingnotes.map(&:name).map { |t| link_to t, tastingnotes_path(t) }.join(', ') %>
你可以試試
def tastingnotes
notes.pluck(:name)
end
和
<%= raw @roast.tastingnotes.map { |t| link_to t, tastingnotes_path(t) } %>
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