The <a4j:log > component generates JavaScript that opens a debug window with useful debug information.

The <a4j:log > component generates JavaScript that opens a log window with useful debug information, which contains data on requests and responses, DOM tree changes et al. The log could be generated not only in a new window, but also on the current page in a separate <div> element. This feature is controlled with the component "popup" attribute. The window is opened on pressing of "CTRL+SHIFT+L", which is default registered key. The hot key could be changed with the "hotkey" attribute, where it's necessary to define one letter that together with "CTRL+SHIFT" opens a window.

The "level" attribute has several possible values "FATAL", "ERROR", "WARN", "INFO", "ALL" and is used when it is necessary to change a logging level.

Example:

<a4j:log level="ALL" popup="false" width="400" height="200"/>

The component defined this way is decoded on a page as <div> inside a page, where all the information beginning with informational message is generated.

Table of <a4j:log> attributes.

Visit the Log page at RichFaces LiveDemo for example of component usage and their sources.

You can find some cases when <a4j:log> might cause JavaScript error on Ajax Core Components Page.