The Mozilla Developer Network page on the browser-provided Javascript console object says: "Note: At least in Firefox, if a page defines a console object, that object overrides the one built into Firefox.". Is there any way to overwrite this object, but still interact with the browser's Web Console?
A use case is to intercept console.log() calls and do something extra or take different parameters, such as a log classification, while retaining the line number/file information provided when logging to console by tools like Firebug or Google Chrome Inspect Element. The closest matching answer I could find is: Intercepting web browser console messages, but it doesn't dive into interacting with the web console through a custom console object, and using a custom defined debug service like
debug.log = function(string, logLevel) {
checkLogLevel(logLevel); // return false if environment log setting is below logLevel
var changedString = manipulate(string);
console.log(changedString);
}
doesn't retain the line number/file source of the function calling debug.log(). An option is to do something with console.trace() and crawl one level up the trace stack, but I was curious about extending console.log() first. I'd also like to find a solution that works with existing Web Consoles/tools like Firebug rather than creating a custom browser extension or Firebug plugin, but if anybody knows of existing solutions for this I'd be interested in them.
Obviously something like:
console = {
log: function (string) {
console.log('hey!');
}
}
console.log('hey!');
won't work and results in infinite recursion.
It's easy, just save a reference to the (original) console before overwriting it:
var originalConsole = window.console;
console = {
log: function(message) {
originalConsole.log(message);
// do whatever custom thing you want
}
}