javascript - 如何从 Rails Controller 设置 morris.js 值

Question

我很难在我的运动应用程序中添加圆形图。是否可以将 morris.js 值设置为 Controller 中的变量？我在 Controller 中有 @diet_calories 变量，我想以 60% -> 20% -> 20% 关系显示碳水化合物 -> 蛋白质 -> 脂肪。如果我在脚本标记中设置碳水化合物的值(值:@diet_calories * 0.6)，它就不起作用。您有什么建议来解决这个问题吗？

application.html.erb:

<script>
    new Morris.Donut({
         element: 'diet-circle',
         data: [
           { label: "Carbs", value: @diet_calories * 0.6 },
           { label: "Protein", value: @diet_calories * 0.2 },
           { label: "Fat", value: @diet_calories * 0.2 }
         ]
    });
</script>

info_controller.rb:

def diet
    if current_user.activity == "Sedentary"
        if current_user.goals == "Lose Weight"
            @diet_calories = ((@bmr * 1.1) - 300).to_i
        elsif current_user.goals == "Maintain Weight"
            @diet_calories = (@bmr * 1.1).to_i
        elsif current_user.goals == "Add some weight"
            @diet_calories = ((@bmr * 1.1) + 300).to_i
        end
    elsif current_user.activity == "Low"
        if current_user.goals == "Lose Weight"
            @diet_calories = ((@bmr * 1.5) - 300).to_i
        elsif current_user.goals == "Maintain Weight"
            @diet_calories = (@bmr * 1.5).to_i
        elsif current_user.goals == "Add some weight"
            @diet_calories = ((@bmr * 1.5) + 300).to_i
        end
    elsif current_user.activity == "Medium"
        if current_user.goals == "Lose Weight"
            @diet_calories = ((@bmr * 1.7) - 300).to_i
        elsif current_user.goals == "Maintain Weight"
            @diet_calories = (@bmr * 1.7).to_i
        elsif current_user.goals == "Add some weight"
            @diet_calories = ((@bmr * 1.7) + 300).to_i
        end
    elsif current_user.activity == "High"
        if current_user.goals == "Lose Weight"
            @diet_calories = ((@bmr * 2.1) - 300).to_i
        elsif current_user.goals == "Maintain Weight"
            @diet_calories = (@bmr * 2.1).to_i
        elsif current_user.goals == "Add some weight"
            @diet_calories = ((@bmr * 2.1) + 300).to_i
        end
    end

diet.html.erb:

<div id="diet-circle"></div>

Answer 1

尝试:

<script>
    new Morris.Donut({
         element: 'diet-circle',
         data: [
           { label: "Carbs", value: <%= @diet_calories %> * 0.6  },
           { label: "Protein", value: <%= @diet_calories %> * 0.2 },
           { label: "Fat", value: <%= @diet_calories %> * 0.2 }
         ]
    });
</script>

.erb代表嵌入式 Ruby。在 .erb文件来评估 Ruby 代码(例如使用 Controller 中设置的实例变量)，您需要使用 <%= ruby code %>

您可以阅读 Erb 模板简介 here