// $Id: debug.js,v 1.9 2004/09/29 10:39:21 cscharf Exp $ // $Date: 2004/09/29 10:39:21 $ // $Author: cscharf $ // -- Debugging Window -- // Global flag to use to enable/disable error messages. var DEBUGGING_ENABLED = false; var debugWindow; // Creates a pop-up window and draws messages into it. If the window already // exists it will reuse it. // // functionName: Header of the message block. // error: Text of the messag block. // isImportant: Optional parameter which will highlight the block when set to // true. function debug( functionName, error, isImportant ) { if( !DEBUGGING_ENABLED ) return; // Test to see if the debug window exists and if we have permission to // write into it. We lose access rights when the URL changes and have // to recreate the window. try { var accessTest = debugWindow.document.documentElement; delete accessTest; } catch( exception ) { debugWindow = null; } if( !debugWindow ) { debugWindow = window.open( null, 'debugWindow', 'width=500, height=650, scrollbars=yes, resizable=yes' ); var debugDocument = debugWindow.document; with( debugDocument ) { open( ); writeln( '' ); writeln( '' ); writeln( 'Javascript Debug Log' ); writeln( '' ); writeln( '' ); writeln( '' ); writeln( '

' ); writeln( 'Debug log for: ' ); writeln( document.location ); writeln( '

' ); writeln( '' ); writeln( '' ); writeln( '
' ); writeln( '' ); writeln( '' ); writeln( '' ); writeln( '' ); close( ); } } if( isImportant ) { var headerText = debugWindow.document.createTextNode( ' === ' + functionName + ' === ' ); var headerNode = debugWindow.document.createElement( 'em' ); headerNode.appendChild( headerText ); } else var headerNode = debugWindow.document.createTextNode( functionName ); var messageHeader = debugWindow.document.createElement( 'h2' ); messageHeader.appendChild( headerNode ); debugWindow.document.getElementById( 'errorLocation' ).appendChild( messageHeader ); var messageBody = debugWindow.document.createElement( 'pre' ); messageBody.appendChild( debugWindow.document.createTextNode( error ) ); // This would be safer, but it's harder to read. Maybe just escape // tags? //messageBody.appendChild( debugWindow.document.createTextNode( encodeHTML( error ) ) ); var codeTag = debugWindow.document.createElement( 'code' ); codeTag.appendChild( messageBody ); var pTag = debugWindow.document.createElement( 'p' ); pTag.appendChild( codeTag ); debugWindow.document.getElementById( 'errorLocation' ).appendChild( pTag ); // This gets really annoying with event handlers. if( isImportant ) debugWindow.focus( ); } // Registers a global error catching event handler. This will catch all // javascript errors that the window generates. If this function returns false // the error will be displayed as normal. If it returns true the browser will // silently drop it. window.onerror = function( message, location, lineNumber ) { debug( location + ' at line ' + lineNumber, message ); return !DEBUGGING_ENABLED; }