Question

我正在为一本厨师食谱写一篇LWRP，而我遇到了一个奇怪的问题，即这个属性在一行上看起来完全有效，而nil则在下一行。source。

来自提供商代码，def create_check cookbook_file get_check_filename(@current_resource.checkname) do source "checks/#{@current_resource.checkname}" # undefined method `checkname' for nil:NilClass mode '0644' action :create end end行上的错误：

load_current_resource

和def load_current_resource @current_resource = Chef::Resource::OmdCheck.new(@new_resource_name) @current_resource.checkname(@new_resource.checkname) # right here! @current_resource.sitename(@new_resource.sitename) @current_resource.sitecfgroot(sprintf(CMK_CFGROOT_FRM, @new_resource.sitename)) @current_resource.perfometer(@new_resource.perfometer) @current_resource.pnptemplate(@new_resource.pnptemplate) @current_resource.exists = check_exists?(@current_resource.checkname) end方法只是为了表明已初始化：

var routineMgr: routineManager = routineManager();
struct routine{
    var name = "Name";
    var tasks = [String]();

    mutating func addTask(task: String){
        tasks.append(task)
    }
}

class routineManager: NSObject {
var routines = [routine]();

    func addTask(name: String, desc: String){
        routines.append(routine(name: name, tasks: ["Hallo","Moin"]));
        routines[0].addTask("Salut")
    }  
}

非常感谢任何帮助。

Answer 1

所以我得到了#chef的答案：

<@coderanger> Sammitch: Use current_resource, not @current_resource
< Sammitch> it's passed in as an instance var?
<@coderanger> Sammitch: No, its actually a method on Provider
<@coderanger> as is new_resource
<@coderanger> the issue is that the block on a resource is evaluated against the resource object
<@coderanger> So in there, @foo is looking at an ivar on the new resource object
<@coderanger> _but_ there is some magic
<@coderanger> Chef::Resource has a method_missing to forward unknown method calls to the enclosing provider
<@coderanger> So #current_resource gets forwarded up for you
<@coderanger> Basically never use the ivar form
<@coderanger> Always new_resource and current_resource instead
<@coderanger> and it will mostly JFW

就Ruby和Chef而言，我是绿色的，所以只有20％对我有意义，但我修改了我的代码到下面并且它有效：

def create_check
  cookbook_file get_check_filename(@current_resource.checkname) do
    source  "checks/#{current_resource.checkname}" # removed the @
    mode    '0644'
    action  :create
  end
end

Answer 2

您通常必须将方法放入＆＃34;＃{}＆＃34; in（）
示例：

"#{method}"        # does not work
"#{(method)}"      # works
a = method; "#{a}" # works too

厨师LWRP＆＃34;未定义的方法＆＃39; checkname＆＃39;为零：NilClass＆＃34;

2 个答案: