061 part 1 - make applicable user roles available in the app

[LDSamson]

This is step 1 to resolve #61 .

After this PR is implemented, the application will:

1. read all user roles (dependent on the config settings - posit connect, shinyproxy, or shinymanager deployment)
2. select the roles applicable for ClinSight (as defined in the golem-config.yml)

In the rare case that multiple roles are available, it will select the first role available (in the order as defined in the config file.
If no roles are available, an empty character will be provided as user role.

[LDSamson]

@jthompson-arcus and @aclark02-arcus this PR is ready. Would one of you be able to review this somehwere this week?

This is the 'base' PR for some (soon available) follow-up PRs that ultimately will make the user role visible in multiple places in the application, and will document the role together with the user name when needed.

[LDSamson]

@jthompson-arcus I noticed that the input of the HTTP header that contains the role information in ShinyProxy needs sanitizing; it gives the roles in all capital letters, and returns a single string, with all roles separated with commas. Therefore, the changes in my latest PR do not yet work properly in the production environment.

I am working on a change to fix this. In general, I will do something like this for both the posit_connect group variable and the shinyproxy one:

trimws(unlist(strsplit(tolower(USER_GROUP_VARIABLE), ",")))

I think if the string is already sanitized, this will not change the outcome. However, please let me know if this is not the case or if this is not desirable for deployment using posit connect

[jthompson-arcus]

@jthompson-arcus I noticed that the input of the HTTP header that contains the role information in ShinyProxy needs sanitizing; it gives the roles in all capital letters, and returns a single string, with all roles separated with commas. Therefore, the changes in my latest PR do not yet work properly in the production environment.

I am working on a change to fix this. In general, I will do something like this for both the posit_connect group variable and the shinyproxy one:

trimws(unlist(strsplit(tolower(USER_GROUP_VARIABLE), ",")))

I think if the string is already sanitized, this will not change the outcome. However, please let me know if this is not the case or if this is not desirable for deployment using posit connect

Connect will already parse the object with that deployment. Shiny will see the object as a list.

[LDSamson]

@jthompson-arcus I noticed that the input of the HTTP header that contains the role information in ShinyProxy needs sanitizing; it gives the roles in all capital letters, and returns a single string, with all roles separated with commas. Therefore, the changes in my latest PR do not yet work properly in the production environment.
I am working on a change to fix this. In general, I will do something like this for both the posit_connect group variable and the shinyproxy one:

trimws(unlist(strsplit(tolower(USER_GROUP_VARIABLE), ",")))

I think if the string is already sanitized, this will not change the outcome. However, please let me know if this is not the case or if this is not desirable for deployment using posit connect

Connect will already parse the object with that deployment. Shiny will see the object as a list.

Okay I will fix it so that it also works with posit connect

[jthompson-arcus]

Few discussion points below.

Sorry if any comments are addressed in the follow up PRs. I tried to cross reference a little.

[jthompson-arcus]

LGTM