When the reconnect(presentationId) method is called on a PresentationRequest presentationRequest, the user agent MUST run the following steps to reconnect to a presentation:

• presentationRequest, the PresentationRequest object that reconnect() was called on.
• presentationId, a valid presentation identifier

P, a Promise.

1. Using the document's settings object run the prohibits mixed security contexts algorithm.
2. If the result of the algorithm is "Prohibits Mixed Security Contexts" and the presentation request URL of presentationRequest is an a priori unauthenticated URL, then return a Promise rejected with a SecurityError and abort these steps.
3. If the document object's active sandboxing flag set has the sandboxed presentation browsing context flag set, then return a Promise rejected with a SecurityError and abort these steps.
4. Let P be a new Promise.
5. Return P but continue running these steps in parallel.
6. Search the set of controlled presentations for a PresentationConnection that meets the following criteria: its controlling browsing context is the current browsing context, its presentation connection state is not terminated, its presentation URL is equal to one of the presentation request URLs of presentationRequest and its presentation identifier is equal to presentationId.
7. If such a PresentationConnection exists, run the following steps:
   1. Let S be that PresentationConnection.
   2. Resolve P with S.
   3. If the presentation connection state of S is connecting or connected, then abort all remaining steps.
   4. Set the presentation connection state of S to connecting.
   5. Establish a presentation connection with S.
   6. Abort all remaining steps.
8. Search the set of controlled presentations for the first PresentationConnection that meets the following criteria: its presentation connection state is not terminated, its presentation URL is equal to one of the presentation request URLs of presentationRequest, and its presentation identifier is equal to presentationId.
9. If such a PresentationConnection exists, let E be that PresentationConnection, and run the following steps:
   1. Create a new PresentationConnection S.
   2. Set the presentation identifier of S to presentationId.
   3. Set the presentation URL of S to the presentation URL of E.
   4. Set the presentation connection state of S to connecting.
   5. Add S to the set of controlled presentations.
   6. Resolve P with S.
   7. Queue a task to fire a trusted event with the name connectionavailable, that uses the PresentationConnectionAvailableEvent interface with the connection attribute initialized to S, at presentationRequest. The event must not bubble and cancelable and should have no default action.
   8. Establish a presentation connection with S.
   9. Abort all remaining steps.
10. Reject P with a NotFoundError exception.