Revise 0273-webengine-projection-mode

[Jack-Byrne]

Introduction

This is a revision to an accepted, and unimplemented proposal (but is currently under review). The suggested revision is to add clarifying language to the Policy Control section of the original proposal about the behavior of including vs omitting the AppHMIType parameter.

Motivation

Traditionally, if the AppHMIType parameter was omitted from an app's policy entry, that implied that all AppHMIType values would be allowed without issue. The language used in the proposal does not explicitly state that the behavior of omitting AppHMIType should change, but it could be implied that AppHMIType: ["WEB_VIEW"] must be included in an app's policy in order for a registration to be allowed. I added a clarifying note to the proposal which will help preserve the original policy behavior in SDL Core.

In addition to the clarifying note, I added an example policy entry that contains the AppHMIType parameter in case some SDLC members were unaware of this parameter's usage.

Proposed Solution

• Add note to the proposal stating the existing behavior of "omitting AppHMIType", and that this behavior should not change.

Note: If the AppHMIType parameter is omitted from app policy, then that app is permitted to use all AppHMIType values. This is an existing behavior in Core and should not be changed for the enforcement of the WEB_VIEW AppHMIType.

Potential Downsides

Preserving the original AppHMIType behavior makes policy control slightly more permissive for WEB_VIEW but I believe this outweighs the downside of including a 1 off exception in the policy table.

Impact On Existing Code

The code under review for this feature will need to be updated in SDL Core to allow all AppHMIType values (including WEB_VIEW) if the AppHMIType param is omitted.

SDL server should make sure AppHMIType is included in an app policy when it is specified.

Alternatives Considered

Use the implementation where AppHMIType: ["WEB_VIEW"] must be defined in the policy table.

[Jack-Byrne]

@theresalech Ready for review

[theresalech]

Hi @JackLivio I've suggested one change to your PR, and also noted a few changes that should be made to the PR description:

• Please update the last sentence of the Motivation section to:

In addition to the clarifying note, I added an example policy entry that contains the AppHMIType parameter in case some SDLC members were unaware of this parameter's usage.

• Please change "The Code under review..." to "The code under review..." in the Potential Downsides section.
• Please add consistent code blocks to AppHMIType and WEB_VIEW throughout the description.

[theresalech]

Suggested change

	Note: If the AppHMIType parameter is omitted from app policy, then that app is permitted to use all AppHMITypes. This is an existing behavior in Core and should not be changed for the enforcement of the `WEB_VIEW` `AppHMIType`.
	Note: If the `AppHMIType` parameter is omitted from app policy, then that app is permitted to use all AppHMITypes. This is an existing behavior in Core and should not be changed for the enforcement of the `WEB_VIEW` `AppHMIType`.

[theresalech]

Please update this in the PR description as well.

[Jack-Byrne]

@theresalech Ready for review

[theresalech]

Author has withdrawn this proposal. Closing PR.