GPII-1251: Fixed to merge cleanly and work with the review 4 branch

documentation/PCPChannel.md

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+## The PCP Interface
+
+This document describes how the __PCP Interface__ works and what its API is.
+
+### Introduction
+The PCP stands for the Personal Control Panel and can be considered the GPIIs main place for displaying messages to the user as well as providing the user with a place to adjust some of their settings, along with other useful controls
+
+The PCP Interface can be connected to via the web socket: `http://localhost:8081/pcpChannel` and its API provide functionality for:
+* Notifying when a user is logging in and logging out
+* Sending a list of desired adjusters to the PCP
+* Sending messages to be displayed in the PCP
+* Receiving responses to messages from PCP
+
+Message types:
+(Info<- default), Error, Warning
+{
+    type: "infoMessage",
+    message: "Howdy user! This is a message to you"
+}
+
+### Internal API
+
+The PCPChannel is a component of the Flowmanager, used in the local/hybrid deployment on the local device. Its 3 main invokers are:
+* `sendUserMessage`: This will send a message to be displayed in the PCP and takes a 'message' and a 'messageType' argument. 
+  * **message** A string to display to the user
+  * **messageType** (optional) should be either "infoMessage", "warningMessage" or "errorMessage" - and will default to "infoMessage" if no second argument is given.
+* `notifyLogin`: Should be called when notifying the PCP of a new user login. It takes two arguments; userToken and adjusters:
+  * **userToken** should be the token of the user logging in
+  * **adjusters** (optional) An object of the adjusters to display as keys and the value to show for the given adjuster as value. Will default to `{ "http://registry.gpii.net/common/highContrastEnabled": false }`
+* `notifyLogout`: Should be called when notifying the PCP of a user logout. Does not take any arguments
+
+
+### External API
+
+
+#### Connection
+
+Connection to the PCP is done as a WebSockets connection to the URL `/pcpChannel`.
+
+
+#### On login [`login` message]:
+
+When a user logs into the GPII system, it will emit a `login` message to the PCP client. The body of this will be a JSON object with a key `userToken` for the userToken of the user logging in, and a `settings` key with the adjusters to be displayed. An example of a `settings` value is: `{ "http://registry.gpii.net/common/highContrastEnabled": false }`
+
+
+#### On logout [`logout` message]
+
+When a user logs out of the GPII system, it will emit a `logout` message to the PCP client.
+
+
+#### Sending user messages [`message` message]
+
+When the GPII system has a message that it wants the PCP client to display, the system will emit a `message` message. It will have the format:
+
+```
+{
+    "type": "infoMessage",
+    "message": "My message"
+}
+```
+
+Where the `"type"` can be either "infoMessage", "warningMessage" or "errorMessage", and `"message"` will contain the message to be displayed.