Returns a custom strategy. You can set any of the optional properties in paramsBlock.
Property Detail
- (GNSDiscoveryMode) discoveryMode
readnonatomicassign
For nearby device discovery, one device must broadcast a pairing code and the other device must scan for pairing codes.
Because there is no way to negotiate beforehand, the default is for all devices to both broadcast and scan.
This property lets you customize this behavior, restricting your app to either broadcast or scan. For example, consider a mobile app that communicates with a set-top box. If the set-top box is programmed to broadcast a pairing code, the mobile app could be set to scan only, to improve latency.
The default is kGNSDiscoveryModeDefault.
- (GNSDiscoveryMediums) discoveryMediums
readnonatomicassign
Controls which mediums to use to broadcast and scan pairing codes when discovering nearby devices.
See discoveryMode for more details about device discovery.
The default is kGNSDiscoveryMediumsDefault.
- (BOOL) allowInBackground
readnonatomicassign
Try to use the discovery strategy when the app is in the background.
Note that not all strategies will be permitted to run in the background. You can request this here, and depending on other settings and circumstances, the strategy might be allowed to continue in the background. Currently only BLE scans/broadcasts are supported.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-12 UTC."],[[["\u003cp\u003eThe \u003ccode\u003eGNSStrategy\u003c/code\u003e class defines the approach for discovering nearby devices, encompassing discovery mode, mediums, and background operation.\u003c/p\u003e\n"],["\u003cp\u003eYou can obtain a default strategy with preset configurations or customize a strategy by specifying properties using a params block.\u003c/p\u003e\n"],["\u003cp\u003eFor device discovery, one device broadcasts a pairing code, and the other scans; you can customize this behavior by setting the \u003ccode\u003ediscoveryMode\u003c/code\u003e property.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003ediscoveryMediums\u003c/code\u003e property allows controlling the communication channels (e.g., Bluetooth, ultrasound) used for discovering nearby devices.\u003c/p\u003e\n"],["\u003cp\u003eWhile the default setting disallows background operation, you can request background execution for the discovery strategy using \u003ccode\u003eallowInBackground\u003c/code\u003e, although it's not always guaranteed.\u003c/p\u003e\n"]]],[],null,["# GNSStrategy Class\n\n[Class Methods](#pub-static-methods) \\| [Properties](#properties) \nGNSStrategy Class Reference \n\nOverview\n--------\n\nThe strategy to use to detect nearby devices.\n\nInherits NSObject.\n\n|----------------|---------------------------------------------------------------------------------------------------------------------------------------|\n| Class Method Summary -------------------- ||\n| (instancetype) | + [strategy](/nearby/messages/ios/reference/interface_g_n_s_strategy#afc67e9c07852a35945a13998bac050ed) |\n| | Returns the default strategy, which uses the default values for all properties. [More...](#afc67e9c07852a35945a13998bac050ed) |\n| ||\n| (instancetype) | + [strategyWithParamsBlock:](/nearby/messages/ios/reference/interface_g_n_s_strategy#af97d06481398cf1e5d7f2f8b54026966) |\n| | Returns a custom strategy. You can set any of the optional properties in `paramsBlock`. [More...](#af97d06481398cf1e5d7f2f8b54026966) |\n| ||\n\n|---------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| Property Summary ---------------- ||\n| GNSDiscoveryMode | [discoveryMode](/nearby/messages/ios/reference/interface_g_n_s_strategy#ad10088af20c44daa2d29f9099b9d6422) |\n| | For nearby device discovery, one device must broadcast a pairing code and the other device must scan for pairing codes. [More...](#ad10088af20c44daa2d29f9099b9d6422) |\n| ||\n| GNSDiscoveryMediums | [discoveryMediums](/nearby/messages/ios/reference/interface_g_n_s_strategy#ad9b6ae317c7ba8ba3ca9da28f831ae0a) |\n| | Controls which mediums to use to broadcast and scan pairing codes when discovering nearby devices. [More...](#ad9b6ae317c7ba8ba3ca9da28f831ae0a) |\n| ||\n| BOOL | [allowInBackground](/nearby/messages/ios/reference/interface_g_n_s_strategy#a4794a869b9225cca308c30e40905f39c) |\n| | Try to use the discovery strategy when the app is in the background. [More...](#a4794a869b9225cca308c30e40905f39c) |\n| ||\n\nMethod Detail\n-------------\n\n|---------------------------|---|---|---|\n| + (instancetype) strategy | | | |\n\nReturns the default strategy, which uses the default values for all properties. \n\n|-------------------------------------------|---|----------------------------------------------------------------------------------------------------|---------------|---|\n| + (instancetype) strategyWithParamsBlock: | | (void(\\^)([GNSStrategyParams](/nearby/messages/ios/reference/interface_g_n_s_strategy_params) \\*)) | *paramsBlock* | |\n\nReturns a custom strategy. You can set any of the optional properties in `paramsBlock`.\n\nProperty Detail\n---------------\n\n|-------------------------------------------------------------------------------|---------------------|\n| |------------------------------------| | - (GNSDiscoveryMode) discoveryMode | | readnonatomicassign |\n\nFor nearby device discovery, one device must broadcast a pairing code and the other device must scan for pairing codes.\n\nBecause there is no way to negotiate beforehand, the default is for all devices to both broadcast and scan.\n\nThis property lets you customize this behavior, restricting your app to either broadcast or scan. For example, consider a mobile app that communicates with a set-top box. If the set-top box is programmed to broadcast a pairing code, the mobile app could be set to scan only, to improve latency.\n\nThe default is `kGNSDiscoveryModeDefault`. \n\n|-------------------------------------------------------------------------------------------|---------------------|\n| |------------------------------------------| | - (GNSDiscoveryMediums) discoveryMediums | | readnonatomicassign |\n\nControls which mediums to use to broadcast and scan pairing codes when discovering nearby devices.\n\nSee `discoveryMode` for more details about device discovery.\n\nThe default is `kGNSDiscoveryMediumsDefault`. \n\n|---------------------------------------------------------------|---------------------|\n| |----------------------------| | - (BOOL) allowInBackground | | readnonatomicassign |\n\nTry to use the discovery strategy when the app is in the background.\n\nNote that not all strategies will be permitted to run in the background. You can request this here, and depending on other settings and circumstances, the strategy might be allowed to continue in the background. Currently only BLE scans/broadcasts are supported.\n\nThe default is `NO`."]]
