Cache object expiration

[Guest]

Hello All,

I inserted an object into cache with absolute expiration using the following
code:

DateTime AbsoluteExpirationDate = DateRangesForDataLists[0,0].AddDays(1);

//Expires the next day
Cache.Insert("DataListStartEndDates",DateRangesForDataLists,null,AbsoluteExpirationDate,TimeSpan.Zero);

How can I know if the above cache object expired or not before accessing? Is
there any API in cache class that I could use?

Any pointers?

Thank you.

 

[Guest]

the simplest way to test for expiration is to check if the Cache item is null:

if Cache["DataListStartEndDates"]==null)
{
// re-add the item here
}

You can also configure CacheItemRemoved calllback that gets fired when the
item is evicted from the Cache. the documentation at MSDN or in your local
help shows example code.
Peter

 

[Guest]

So if the cache object's expiration has expired it is instantly set to null?

Thank you.

the simplest way to test for expiration is to check if the Cache item is null:

if Cache["DataListStartEndDates"]==null)
{
// re-add the item here
}

You can also configure CacheItemRemoved calllback that gets fired when the
item is evicted from the Cache. the documentation at MSDN or in your local
help shows example code.
Peter


--
Co-founder, Eggheadcafe.com developer portal:
http://www.eggheadcafe.com
UnBlog:
http://petesbloggerama.blogspot.com

Hello All,

I inserted an object into cache with absolute expiration using the following
code:

DateTime AbsoluteExpirationDate = DateRangesForDataLists[0,0].AddDays(1);

//Expires the next day
Cache.Insert("DataListStartEndDates",DateRangesForDataLists,null,AbsoluteExpirationDate,TimeSpan.Zero);

How can I know if the above cache object expired or not before accessing? Is
there any API in cache class that I could use?

Any pointers?

Thank you.

 

[Guest]

Diffident,
When an object in Cache expires, it is "evicted" - it's no longer there. So
if you look for it by key, you will get null.
Actually testing for null before attempting to access anything in Cache ,
Session, Application or Viewstate is a good programming practice.
Hope that helps.
Peter
--
Co-founder, Eggheadcafe.com developer portal:
http://www.eggheadcafe.com
UnBlog:
http://petesbloggerama.blogspot.com

So if the cache object's expiration has expired it is instantly set to null?

Thank you.

the simplest way to test for expiration is to check if the Cache item is null:

if Cache["DataListStartEndDates"]==null)
{
// re-add the item here
}

You can also configure CacheItemRemoved calllback that gets fired when the
item is evicted from the Cache. the documentation at MSDN or in your local
help shows example code.
Peter


--
Co-founder, Eggheadcafe.com developer portal:
http://www.eggheadcafe.com
UnBlog:
http://petesbloggerama.blogspot.com

Hello All,

I inserted an object into cache with absolute expiration using the following
code:

DateTime AbsoluteExpirationDate = DateRangesForDataLists[0,0].AddDays(1);

//Expires the next day
Cache.Insert("DataListStartEndDates",DateRangesForDataLists,null,AbsoluteExpirationDate,TimeSpan.Zero);

How can I know if the above cache object expired or not before accessing? Is
there any API in cache class that I could use?

Any pointers?

Thank you.

 

[Guest]

Thank you!! That helped.

Diffident,
When an object in Cache expires, it is "evicted" - it's no longer there. So
if you look for it by key, you will get null.
Actually testing for null before attempting to access anything in Cache ,
Session, Application or Viewstate is a good programming practice.
Hope that helps.
Peter
--
Co-founder, Eggheadcafe.com developer portal:
http://www.eggheadcafe.com
UnBlog:
http://petesbloggerama.blogspot.com

So if the cache object's expiration has expired it is instantly set to null?

Thank you.

the simplest way to test for expiration is to check if the Cache item is null:

if Cache["DataListStartEndDates"]==null)
{
// re-add the item here
}

You can also configure CacheItemRemoved calllback that gets fired when the
item is evicted from the Cache. the documentation at MSDN or in your local
help shows example code.
Peter


--
Co-founder, Eggheadcafe.com developer portal:
http://www.eggheadcafe.com
UnBlog:
http://petesbloggerama.blogspot.com




:

Hello All,

I inserted an object into cache with absolute expiration using the following
code:

DateTime AbsoluteExpirationDate = DateRangesForDataLists[0,0].AddDays(1);

//Expires the next day
Cache.Insert("DataListStartEndDates",DateRangesForDataLists,null,AbsoluteExpirationDate,TimeSpan.Zero);

How can I know if the above cache object expired or not before accessing? Is
there any API in cache class that I could use?

Any pointers?

Thank you.