# YUI configuration to filter log messages

This example illustrates how to configure your YUI instance to ignore certain log messages to aid in reducing the signal-to-noise ratio when debugging.

Log messages filtered out from the YUI config are permanently ignored. If you want to be able to temporarily hide and reshow messages, use the ConsoleFilters plugin. It is not uncommon to set up `logInclude` or `logExclude` in the YUI configuration and use the ConsoleFilters plugin.

Log messages can be ignored based on the source (e.g. `event` or `attribute`) or based on their log level (info, warn, error).

#### Source filter

`sourceA` `sourceB` `sourceC`

#### Log level

info warn error

#### Log a message

Source: A B C Category: info warn error

#### Code preview

    // YUI instance configuration
    var Y = YUI({
        "logLevel": "info",
        "logExclude": {
            "sourceC": true
        }
    });

    // Log statement
    Y.log("This is a log message!", "info", "sourceA");