ajax使用formdata 提交excel文件表单到rails解析

 .modal-body
          .container-fluid
            .row
              .col-md-12
                1.下载模板文件
                = link_to '模板文件'
            .row
              .col-md-12
                = form_tag '', :id => "my-form" do
                  .input-group
                    %span.input-group-btn
                      %button#fake-file-button-browse.btn.btn-default{:type => "button"}
                        %span.glyphicon.glyphicon-file
                    = file_field_tag :category_file, :id => "files-input-upload", :style => "display:none"
                    %input#fake-file-input-name.form-control{:disabled => "disabled", :type => "text"}/
                    %span.input-group-btn
                      %button#fake-file-button-upload.btn.btn-default{:disabled => "disabled", :type => "button"}
                        %span.glyphicon.glyphicon-upload

使用formdata得到完整表单，将formdata作为data值传递给后台，就如同点击submit提交数据一样。注意此处的url和type对应的值不能直接写到表单里面，而应写在ajax的配置参数中

  $('#fake-file-button-upload').click(function() {
    var form = new FormData(document.getElementById('my-form'));

    $.ajax({
      url: "/tax_categories/get_category",
      type: "POST",
      data: form,
      dataType: "json",
      processData: false,  // 不处理数据
      contentType: false,  //要加
      success: function(data) {
        console.log(data);
        if (data.result == "error") {
          alert(data.result);
        } else {
          console.log("save success");
          window.location = "/tax_categories"
        }
      }
    });
  });

使用creek解析xml

require 'creek'

def get_category
    flag = true
    begin
      file = params[:category_file]
      creek = Creek::Book.new file.path
      sheet = creek.sheets[0]
      sheet.rows.each do |row|
        puts row
      end
    rescue
      flag = false
    end

    if flag
      respond_to do |f|
        f.json {
          render :json => {:result => "success"}.to_json
        }
      end
    else
      respond_to do |f|
        f.json {
          render :json => {:result => "error"}.to_json
        }
      end
    end
  end

此处还有个比较二的问题，是发生了302重定向，刚开始controller中的代码是如下，在解析成功后想直接跳转，可是在ajax的请求下，产生的是302重定向，在浏览器中并不会显示跳转。所以采用在js中location定位到新的页面

　　if flag
       redirect_to tax_categories_url
    else
      respond_to do |f|
        f.json {
          render :json => {:result => "error"}.to_json
        }
      end
    end