Server Connections

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These functions manage and inspect the network connection between the Meteor client and server.

This method returns the status of the connection between the client and the server. The return value is an object with the following fields:

connectedBoolean

True if currently connected to the server. If false, changes and method invocations will be queued up until the connection is reestablished.

statusString

Describes the current reconnection status. The possible values are connected (the connection is up and running), connecting (disconnected and trying to open a new connection), failed (permanently failed to connect; e.g., the client and server support different versions of DDP), waiting (failed to connect and waiting to try to reconnect) and offline (user has disconnected the connection).

retryCountNumber

The number of times the client has tried to reconnect since the connection was lost. 0 when connected.

retryTimeNumber or undefined

The estimated time of the next reconnection attempt. To turn this into an interval until the next reconnection, use retryTime - (new Date()).getTime(). This key will be set only when status is waiting.

reasonString or undefined

If status is failed, a description of why the connection failed.

Instead of using callbacks to notify you on changes, this is a reactive data source. You can use it in a template or computation to get realtime updates.

Call this method to disconnect from the server and stop all live data updates. While the client is disconnected it will not receive updates to collections, method calls will be queued until the connection is reestablished, and hot code push will be disabled.

Call Meteor.reconnect to reestablish the connection and resume data transfer.

This can be used to save battery on mobile devices when real time updates are not required.

onConnection returns an object with a single method stop. Calling stop unregisters the callback, so that this callback will no longer be called on new connections.

The callback is called with a single argument, the server-side connection representing the connection from the client. This object contains the following fields:

idString

A globally unique id for this connection.

closeFunction

Close this DDP connection. The client is free to reconnect, but will receive a different connection with a new id if it does.

onCloseFunction

Register a callback to be called when the connection is closed. If the connection is already closed, the callback will be called immediately.

clientAddressString

The IP address of the client in dotted form (such as 127.0.0.1).

If you’re running your Meteor server behind a proxy (so that clients are connecting to the proxy instead of to your server directly), you’ll need to set the HTTP_FORWARDED_COUNT environment variable for the correct IP address to be reported by clientAddress.

Set HTTP_FORWARDED_COUNT to an integer representing the number of proxies in front of your server. For example, you’d set it to 1 when your server was behind one proxy.

httpHeadersObject

When the connection came in over an HTTP transport (such as with Meteor’s default SockJS implementation), this field contains whitelisted HTTP headers.

Cookies are deliberately excluded from the headers as they are a security risk for this transport. For details and alternatives, see the SockJS documentation.

Currently when a client reconnects to the server (such as after temporarily losing its Internet connection), it will get a new connection each time. The onConnection callbacks will be called again, and the new connection will have a new connection id.

In the future, when client reconnection is fully implemented, reconnecting from the client will reconnect to the same connection on the server: the onConnection callback won’t be called for that connection again, and the connection will still have the same connection id.

To call methods on another Meteor application or subscribe to its data sets, call DDP.connect with the URL of the application. DDP.connect returns an object which provides:

• subscribe - Subscribe to a record set. See Meteor.subscribe.
• call - Invoke a method. See Meteor.call.
• apply - Invoke a method with an argument array. See Meteor.apply.
• methods - Define client-only stubs for methods defined on the remote server. See Meteor.methods.
• status - Get the current connection status. See Meteor.status.
• reconnect - See Meteor.reconnect.
• disconnect - See Meteor.disconnect.

By default, clients open a connection to the server from which they’re loaded. When you call Meteor.subscribe, Meteor.status, Meteor.call, and Meteor.apply, you are using a connection back to that default server.