# what is the META property of UPROPERTY?

**URL:** <https://forums.unrealengine.com/t/what-is-the-meta-property-of-uproperty/88618>\
**Category:** C++\
**Tags:** unreal-engine\
**Created:** [March 27, 2017, 12:58pm UTC](https://forums.unrealengine.com/t/what-is-the-meta-property-of-uproperty/88618 "2017-03-27T12:58:41Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![ikfk](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ikfk](https://forums.unrealengine.com/u/ikfk)\
**Post date:** [March 27, 2017, 12:58pm UTC](https://forums.unrealengine.com/t/what-is-the-meta-property-of-uproperty/88618/1 "2017-03-27T12:58:41Z")

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in the tutorial batterycollector , that girl write this  
UPROPERTY(VisibleAnywhere,BlueprintReadOnly,Category = “PickupMesh”,meta = (AllowPrivateAccess = “true”))

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looks like this is all the valid meta propertis?

where is this “AllowPrivateAccess” come from? even not found it in any very offical document

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**Author:** ![ExtraLifeMatt](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/extralifematt/32/918695_2.png) [@ExtraLifeMatt](https://forums.unrealengine.com/u/ExtraLifeMatt)\
**Post date:** [March 27, 2017, 2:16pm UTC](https://forums.unrealengine.com/t/what-is-the-meta-property-of-uproperty/88618/2 "2017-03-27T14:16:04Z")

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The Wiki is user maintained, so don’t take it as authoritative. Feel free to update it as you find missing items (like this one) 🙂

If you search for AllowPrivateAccess you can find some documentation within the code base as to what it does:

> [@](#):
>
> // The AllowPrivateAccess meta flag will allow this (property) to be exposed to Blueprint, but only to graphs internal to this class.

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**Author:** ![ikfk](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ikfk](https://forums.unrealengine.com/u/ikfk)\
**Post date:** [March 27, 2017, 2:47pm UTC](https://forums.unrealengine.com/t/what-is-the-meta-property-of-uproperty/88618/3 "2017-03-27T14:47:23Z")

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thank you!

where can i get a sneak peek at all these mysterious meta flags？:rolleyes:

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**Author:** ![Fitz](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/fitz/32/1078894_2.png) [@Fitz](https://forums.unrealengine.com/u/Fitz)\
**Post date:** [March 27, 2017, 3:20pm UTC](https://forums.unrealengine.com/t/what-is-the-meta-property-of-uproperty/88618/4 "2017-03-27T15:20:47Z")

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In \Engine\Source\Runtime\CoreUObject\Public\UObject\ObjectMacros.h you will find a number of enums which define the various parameters to the UE4 macros (UCLASS, USTRUCT, UPROPERTY etc). I think the first super good info starts at namespace UC (the values you can pass to a UCLASS macro), but keep scrolling down to namespace UM for the metadata related definitions.

Another place to look is in the FBlueprintMetadata struct which is defined in \Engine\Source\Editor\BlueprintGraph\Classes\EdGraphSchema\_K2.h. These are variable names such as “MD\_ChildCanTick” but as you might deduce, the Meta value would be “ChildCanTick” which is defined in the associated cpp file.

Cheers,

Jonathan

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**Author:** ![ikfk](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ikfk](https://forums.unrealengine.com/u/ikfk)\
**Post date:** [March 28, 2017, 2:25am UTC](https://forums.unrealengine.com/t/what-is-the-meta-property-of-uproperty/88618/5 "2017-03-28T02:25:32Z")

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> [@'\[EPIC](#):
>
> Fitz;686514’]In \Engine\Source\Runtime\CoreUObject\Public\UObject\ObjectMacros.h you will find a number of enums which define the various parameters to the UE4 macros (UCLASS, USTRUCT, UPROPERTY etc). I think the first super good info starts at namespace UC (the values you can pass to a UCLASS macro), but keep scrolling down to namespace UM for the metadata related definitions.
> 
> Another place to look is in the FBlueprintMetadata struct which is defined in \Engine\Source\Editor\BlueprintGraph\Classes\EdGraphSchema\_K2.h. These are variable names such as “MD\_ChildCanTick” but as you might deduce, the Meta value would be “ChildCanTick” which is defined in the associated cpp file.
> 
> Cheers,
> 
> Jonathan

cooool! really appreciate thanks!