变量值在ColdFusion中的请求之间变化(Variable values changing between requests in ColdFusion)

变量值在ColdFusion中的请求之间变化(Variable values changing between requests in ColdFusion)

请考虑以下代码：

<cfset local.quiz = getQuiz(param1,param2) /> <!--- returns a struct that has a key called unlock_at ---> <cfset quiz.unlock_at = (quiz.unlock_at EQ '') ? '' : DateConvert('utc2Local',createODBCDateTime(ISOToDateTime(quiz.unlock_at))) />

这就是我原创编写代码的方式。 当我多次调用运行此代码的页面时， quiz.unlock_at的值以6小时为增量（函数中的调整量）发生变化。 当我说增量时我的意思是第一页加载时间是说12:00。 下一页加载6:00，下一页加载00:00，依此类推。 每次物理时间都在变化。 我将代码更改为：

<cfset local.unlock_at = (quiz.unlock_at EQ '') ? '' : DateConvert('utc2Local',createODBCDateTime(ISOToDateTime('#quiz.unlock_at#'))) />

第一件事是我将值存储在局部变量中，不再更新现有的struct。 第二件事是我将日期作为字符串传递给函数而不是变量。 我不确定它是如何改变的。 在任一情况下：

请求之间如何变化。 我不认为这些变量存在于页面请求之间。 所有这些代码都位于CFC内部的函数内。 这些数据中的任何内容都是持久的。 我打了几次电话，看了日期变化然后打开了一个新的浏览器，数据也被改变了。 怎么可能？

这是一个范围问题，组件的数据持久性问题？ 告诉我一个循环，我仍然不确定发生了什么，直到我这样做，我担心我可能还有其他问题。

Consider the following code:

<cfset local.quiz = getQuiz(param1,param2) /> <!--- returns a struct that has a key called unlock_at ---> <cfset quiz.unlock_at = (quiz.unlock_at EQ '') ? '' : DateConvert('utc2Local',createODBCDateTime(ISOToDateTime(quiz.unlock_at))) />

This is how I origionally wrote my code. When I called the page that ran this code multiple times, the value of quiz.unlock_at was changing in 6 hour increments (the amount of adjustment in the function). When I say increments I mean first page load the time was say 12:00. The next page load 6:00, the next page load 00:00 and so on. The physical time was changing each time. I changed the code to this:

<cfset local.unlock_at = (quiz.unlock_at EQ '') ? '' : DateConvert('utc2Local',createODBCDateTime(ISOToDateTime('#quiz.unlock_at#'))) />

The first thing is I'm storing the value in a local variable and no longer updating the existing struct. The second thing is I am passing in the date to the function as a string and not as the variable. I wasn't sure how it was getting altered. In either case:

How the heck was this changing between requests. I didn't think these variables lives between page requests. All of this code is inside a function that lives inside a CFC. What of any of that data is persistent. I called the page a few times and watched the dates change then opened a NEW browser and the data was altered too. How is that possible?

Is this a scoping issue, a data persistence issue with components? Threw me for a loop and I still and not sure what happened and until I do I'm afraid I may have other issues.

最满意答案

我想到了。 哎呀...

函数getQuiz创建了一个结构，然后缓存它。 原因是它是一个API调用，我不希望每次都为不经常更改的数据运行API调用。 所以我在做的是：

<cffunction name="getQuiz"> <cfset local.variable = {} /> <!--- Load Sturct Data ---> <!--- CachePut the variable ---> <cfreturn variable /> </cffunction> <cfset quiz = getQuiz() /> <cfset quiz.unlock_at = 1 /> <!--- At this point I have actually edited a direct reference to the cached variable quiz even though I tried locally scoping it etc.

因此，显然返回结构与将结构传递给函数是一样的，即它通过引用而不是通过值传递结构。 出于某种原因，我认为返回一个结构并没有将它作为引用返回，但它是有道理的，因为这是CF在函数之间传递值的方式。

I figured it out. Grrr...

The function getQuiz created a struct and then cached it. The reason being is that it's an API call and I don't want to have to run an API call every time for data that doesn't change that often. So what I was doing was:

<cffunction name="getQuiz"> <cfset local.variable = {} /> <!--- Load Sturct Data ---> <!--- CachePut the variable ---> <cfreturn variable /> </cffunction> <cfset quiz = getQuiz() /> <cfset quiz.unlock_at = 1 /> <!--- At this point I have actually edited a direct reference to the cached variable quiz even though I tried locally scoping it etc.

So, apparently returning a struct is the same as passing a struct into a function, i.e. it passes the struct by reference not by value. For some reason I thought returning a struct didn't return it as a reference, but it makes sense because that is the way CF passes values between functions.