Question

我正在尝试使用rails with react，只需在我正在处理的应用程序中添加一个评论部分。 /comments页面有效。但是当我试图发表新评论时。我收到这个错误。我回到了我正在使用的指南，并没有解释任何关于此的内容。我是铁杆的新手并做出反应，如果有人能帮助我，我会很感激。

应用程序跟踪：

app/views/comments/_form.html.erb:20:in `block in_app_views_comments__form_html_erb__930297241_104622300'
app/views/comments/_form.html.erb:1:in `_app_views_comments__form_html_erb__930297241_104622300'
app/views/comments/new.html.erb:3:in `_app_views_comments_new_html_erb__151456299_104688260'

comments_controller.rb：

class CommentsController < ApplicationController
    before_action :set_comment, only: [:show, :edit, :update, :destroy]

    # GET /comments
    # GET /comments.json
    def index
        @comments = Comment.all
    end

    # GET /comments/1
    # GET /comments/1.json
    def show
    end

    # GET /comments/new
    def new
        @comment = Comment.new
    end

    # GET /comments/1/edit
    def edit
    end

    # POST /comments
    # POST /comments.json
    def create
        @comment = Comment.new(comment_params)

        respond_to do |format|
            if @comment.save
                format.html { redirect_to @comment, notice: 'Comment was successfully created.' }
                format.json { render :show, status: :created, location: @comment }
            else
                format.html { render :new }
                format.json { render json: @comment.errors, status: :unprocessable_entity }
            end
        end
    end

    # PATCH/PUT /comments/1
    # PATCH/PUT /comments/1.json
    def update
        respond_to do |format|
            if @comment.update(comment_params)
                format.html { redirect_to @comment, notice: 'Comment was successfully updated.' }
                format.json { render :show, status: :ok, location: @comment }
            else
                format.html { render :edit }
                format.json { render json: @comment.errors, status: :unprocessable_entity }
            end
        end
    end

    # DELETE /comments/1
    # DELETE /comments/1.json
    def destroy
        @comment.destroy
        respond_to do |format|
            format.html { redirect_to comments_url, notice: 'Comment was successfully destroyed.' }
        format.json { head :no_content }
        end
    end

    private
        # Use callbacks to share common setup or constraints between actions.
        def set_comment
            @comment = Comment.find(params[:id])
        end

        # Never trust parameters from the scary internet, only allow the white list through.
        def comment_params
            params.require(:comment).permit(:author, :comment_text)
        end
end

_form.html.erb：

<%= form_for(@comment) do |f| %>
<% if @comment.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(@comment.errors.count, "error") %> prohibited this comment from being saved:</h2>

<ul>
    <% @comment.errors.full_messages.each do |message| %>
        <li><%= message %></li>
    <% end %>
</ul>
</div>
<% end %>

<div class="field">
    <%= f.label :author %><br>
    <%= f.text_field :author %>
</div>
<div class="field">
    <%= f.label :comment_text %><br>
    <%= f.text_area :comment_text %>
</div>
<div class="actions">
    <%= f.submit %>
</div>
<% end %>

new.html.erb：

<h1>New Comment</h1>

<%= render 'form' %>

<%= link_to 'Back', comments_path %>

[时间戳] _create_comments.rb：

class CreateComments < ActiveRecord::Migration
    def change
        create_table :comments do |t|
            t.string :author
            t.text :comment_text

            t.timestamps null: false
        end
    end
end

Answer 1

似乎问题源于您的架构/迁移。这一行：

params.require(:comment).permit(:author, :text)

建议你有一个名为text的列，它是Rails中的数据类型。您应为该列选择一个名为“comment_text”的名称，该名称不会回显数据类型的名称。

您也可以在迁移中转置数据类型和列名称。

CommentsController中的NoMethodError #new undefined method`text＆＃39;对于＃<comment id：=“”nil，=“”author：=“”nil，=“”created_at：=“”nil，=“”updated_at：=“”nil =“”> </comment>

1 个答案: