TriggerClientEvent

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This function triggers an event previously registered on a client. This is the primary means of passing information between the server and the client. Clients have a similar triggerServerEvent function that can do the reverse. You can treat this function as if it was an asynchronous function call, using triggerServerEvent to pass back any returned information if necessary.

Almost any data types can be passed as expected, including elements and complex nested tables. Non-element MTA data types like xmlNodes or resource pointers will not be able to be passed as they do not necessarily have a valid representation on the client.

Events are sent reliably, so clients will receive them, but there may be (but shouldn't be) a significant delay before they are received. You should take this into account when using them.

Keep in mind the bandwidth issues when using events - don't pass a large list of arguments unless you really need to. It is marginally more efficient to pass one large event than two smaller ones.

[[{{{image}}}|link=]] Important Note: Non-element MTA data types like xmlNodes or resource pointers will not be able to be passed as they do not necessarily have a valid representation on the client.
[[{{{image}}}|link=]] Note: It is marginally more efficient to pass one large event than two smaller ones

Syntax

bool triggerClientEvent ( [table/element sendTo=getRootElement()], string name, element sourceElement, [arguments...] )

OOP Syntax Help! I don't understand this!

Method: player:triggerEvent(...)

Required Arguments

  • name: The name of the event to trigger client side. You should register this event with addEvent and add at least one event handler using addEventHandler.
  • sourceElement: The element that is the source of the event.
[[{{{image}}}|link=]] Note: To save client CPU, you should avoid setting sourceElement to the root element where possible. Using resourceRoot is usually sufficient if the event is handled by the same resource on the client.

Optional Arguments

NOTE: When using optional arguments, you might need to supply all arguments before the one you wish to use. For more information on optional arguments, see optional arguments.

  • sendTo: The event will be sent to all players that are children of the specified element. By default this is the root element, and hence the event is sent to all players. If you specify a single player it will just be sent to that player. This argument can also be a table of player elements.
  • arguments...: A list of arguments to trigger with the event. You can pass any lua data type (except functions). You can also pass elements.

Returns

Returns true if the event trigger has been sent, false if invalid arguments were specified.

Example

Example 1

This example shows how you can pass a simple "Hello World" message from the server to the all the clients using an event.

Click to collapse [-]
Client
function greetingHandler ( message )
    outputChatBox ( "The server says: " .. message )
end
addEvent( "onGreeting", true )
addEventHandler( "onGreeting", localPlayer, greetingHandler )
Click to collapse [-]
Server
function greetingCommand ( playerSource, commandName )
    triggerClientEvent ( playerSource, "onGreeting", playerSource, "Hello World!" )
end
addCommandHandler ( "greet", greetingCommand )

When the command "greet" is executed (by typing it in the server console or the player's console), the server's greetingCommand function is called. This triggers the client side event onGreeting with the string "Hello World!". This event is then handled by the greetingHandler function client side which then displays the message.

Example 2

This example shows how you can pass a simple "Hello World" message from the server to a single client using an event.

Click to collapse [-]
Client
function greetingHandler ( message )
    outputChatBox ( "The server says: " .. message )
end
addEvent( "onGreeting", true )
addEventHandler( "onGreeting", localPlayer, greetingHandler )
Click to collapse [-]
Server
function greetingCommandOne ( playerSource, commandName, playerName )
    if playerName then
        local thePlayer = getPlayerFromName ( playerName )
        if thePlayer then
            triggerClientEvent ( thePlayer, "onGreeting", thePlayer, "Hello World!" )
        else
            -- invalid player name specified
        end
    else
        -- No player name specified
    end 
end
addCommandHandler ( "greet_one", greetingCommandOne )

This works like the first example except an extra thePlayer argument is specified for triggerClientEvent.

Changelog

Version Description
1.3.0-9.04570 Added option to use a list of player elements for the 'sendTo' argument

See Also