# Namespace ImaSdkSettings

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| Enumerations ||
|---|---|
| `https://developers.google.com/interactive-media-ads/docs/sdks/html5/client-side/reference/namespace/google.ima.ImaSdkSettings#google.ima.ImaSdkSettings.CompanionBackfillMode` | Defines a set of constants for the companion backfill setting. |
| `https://developers.google.com/interactive-media-ads/docs/sdks/html5/client-side/reference/namespace/google.ima.ImaSdkSettings#google.ima.ImaSdkSettings.VpaidMode` | A set of constants for enabling VPAID functionality. |

## Enumerations

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### CompanionBackfillMode

`CompanionBackfillMode` Defines a set of constants for the companion backfill setting. This setting indicates whether companions should be backfilled in various scenarios.  


If the value is `ALWAYS`, companion backfill will be attempted in all
situations, even when there is no main ad returned.


If the value is `ON_MASTER_AD`, companion backfill will be attempted if
there is a main ad with fewer companions than there are companion slots. The missing
companions will be backfilled.

The default value is `ALWAYS`.
Note that client-side companion backfill requires tagging your companions properly with a Google Publisher Tag (GPT). To enable backfill, the following changes to standard GPT setup are necessary:

```
 ... let slot1 = googletag.defineSlot('/1234/adunit', [300, 250], 'slot-div'); slot1.addService(googletag.companionAds()).addService(googletag.pubads()); ... googletag.companionAds().setRefreshUnfilledSlots(true); ... googletag.enableServices(); 
```
For autoplay videos, the following additional change is recommended to prevent companion slots from being preloaded and then immediately replaced with companions.

```
 googletag.pubads().disableInitialLoad(); ... googletag.enableServices(); 
```

| Enumeration Members ||
|---|---|
| `ALWAYS` |   |
| `ON_MASTER_AD` |   |

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### VpaidMode

`VpaidMode` A set of constants for enabling VPAID functionality.

| Enumeration Members ||
|---|---|
| `DISABLED` | VPAID ads will not play and an error will be returned. |
| `ENABLED` | VPAID ads are enabled using a cross domain iframe. The VPAID ad cannot access the site. VPAID ads that depend on friendly iframe access may error. This is the default. |
| `INSECURE` | VPAID ads are enabled using a friendly iframe. This allows the ad access to the site through JavaScript. |