使用 mysql 查询数据更新“数字”小部件 - Dashing

Question

我对 ruby​​ 非常陌生，我正在尝试设置一个测试仪表板。我看到 mysql 给出了 sql 查询的总数。但是它没有被填充到小部件上。有人可以帮忙吗？

# mysql.rb (jobs file)    
require "mysql2"

SCHEDULER.every '5s' do
  client = Mysql2::Client.new(:host => "192.168.1.3",:username => "testuser",:database => 'testdb')

  results=client.query("SELECT count(*) as total from testdb.share")
  puts results

  results.each do |row|
    puts row['total']
    send_event('totals', { value: total })
  end
end

仪表板文件：

# sample.erb
<li data-row="1" data-col="1" data-sizex="1" data-sizey="1">
  <div data-id="totals" data-view="Number" data-title="Number of Shares" data-moreinfo="Shares" data-prefix="$"></div>
</li>
....

Dashing 控制台如下图所示

#<Mysql2::Result:0x007f98b4b85d18> 
3   --->>>> This is the count of my mysql query

调度程序捕获异常：

> undefined local variable or method `total' for main:Object
> /home/user/.rvm/sweet_dashboard_project/jobs/mysql.rb:20:in `block (2
> levels) in <top (required)>'
> /home/user/.rvm/sweet_dashboard_project/jobs/mysql.rb:11:in `each'
> /home/user/.rvm/sweet_dashboard_project/jobs/mysql.rb:11:in `block in
> <top (required)>'
> /home/user/.rvm/gems/ruby-2.2.1/gems/rufus-scheduler-2.0.24/lib/rufus/sc/jobs.rb:230:in
> `call'
> /home/user/.rvm/gems/ruby-2.2.1/gems/rufus-scheduler-2.0.24/lib/rufus/sc/jobs.rb:230:in
> `trigger_block'
> /home/user/.rvm/gems/ruby-2.2.1/gems/rufus-scheduler-2.0.24/lib/rufus/sc/jobs.rb:204:in
> `block in trigger'
> /home/user/.rvm/gems/ruby-2.2.1/gems/rufus-scheduler-2.0.24/lib/rufus/sc/scheduler.rb:430:in
> `call'
> /home/user/.rvm/gems/ruby-2.2.1/gems/rufus-scheduler-2.0.24/lib/rufus/sc/scheduler.rb:430:in
> `block in trigger_job'

Answer 1

问题出在这里：

results.each do |row|
  puts row['total']
  send_event('totals', { value: total })
end

检查send_event('totals', { value: total }) 行。您将value 设置为total，但您没有在任何地方设置该变量或方法（即total），因此出现undefined local variable or method 错误。

它认为你想分配row['total']：

results.each do |row|
  puts row['total']
  send_event('totals', { value: row['total'] })
end

更新

要在小部件中显示值，您必须使用current 而不是value 才能获得正确的绑定（在send_event() 中），因此上面的代码变为：

results.each do |row|
  puts row['total']
  send_event('totals', { current: row['total'] })
end

另一种方法是将源文件widgets/number/number.html 中的current 更改为value。

所以这一行：

<h2 class="value" data-bind="current | shortenedNumber | prepend prefix | append suffix"></h2>

会变成：

<h2 class="value" data-bind="value | shortenedNumber | prepend prefix | append suffix"></h2>

虽然我不建议这样做，但最好保留默认值（即current）。