[英]Begin and Rescue block exception handling
I have little experience in rails exception handling. 我在Rails异常处理方面经验很少。 I have this snippet 我有这个片段
def update
@game = Game.find(params[:id])
begin
params[:game][:tier] = eval(params[:game][:tier])
rescue
@game.errors.add(:tier, "Please make sure the correct format for tier, example [100, 1000, 10000]")
end
#.... more code
end
In case params[:game][:tier] = "[100,200]" everything is perfect. 万一params [:game] [:tier] =“ [100,200]”一切就完美了。 In case of error case of ruby syntax like params[:game][:tier] = "[100,200] abc" it catch the error however the application just crush. 如果发生红宝石语法错误,例如params [:game] [:tier] =“ [100,200] abc”,它会捕获错误,但是应用程序会崩溃。
How can I handle exception with 'eval()' such that it won't crush the app? 我该如何使用'eval()'处理异常,以免破坏应用程序? Why begin and rescue does not work in this case? 为什么在这种情况下开始而救援不起作用? Appreciate any help for ruby enlightenment thanks :) 感谢任何对红宝石启发的帮助,谢谢:)
What if params[:game][:tier]
was "[100,200]; system('rm -rf /')"
? 如果params[:game][:tier]
是"[100,200]; system('rm -rf /')"
怎么办?
Since the incoming data is expected to be an array, I would not use eval
but JSON.parse
instead: 由于预期传入数据是一个数组,因此我不使用eval
而是JSON.parse
:
> JSON.parse("[100,200]")
=> [100, 200]
> JSON.parse("[100,200] abc")
JSON::ParserError: 746: unexpected token at 'abc'...
Then rescue from only a JSON::ParserError
exception 然后仅从JSON::ParserError
异常进行救援
rescue JSON::ParserError => e
This will also solve the rescue not catching the exception problem you're having. 这也将解决无法捕获您遇到的异常问题的情况。
however you should rescue in this way 但是你应该这样拯救
def update
@game = Game.find(params[:id])
begin
params[:game][:tier] = eval(params[:game][:tier])
rescue Exception => e
@game.errors.add(:tier, "Please make sure the correct format for tier, example [100, 1000, 10000]")
end
#.... more code
end 结束
in order to make it work 为了使它起作用
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.