/** * This simple function is one of the handiest: pass it an object, and it * will pop an alert() listing all the properties of the object and their * values.(这个函数用来遍历对象的属性及其相应的值,并显示出来) * * @param inObj The object to display properties of. */ jscript.debug.enumProps = function(inObj) {
var props = ""; var i; for (i in inObj) { props += i + " = " + inObj[i] + "\n"; } alert(props);
} // End enumProps().
/** * This is a very simple logger that sends all log messages to a specified * DIV.(这是一个简单的 debug 日志记录系统) */ jscript.debug.DivLogger = function() {
/** * The following are faux constants that define the various levels a log * instance can be set to output.(下面的常量用来定义错误级别) */ this.LEVEL_TRACE = 1; this.LEVEL_DEBUG = 2; this.LEVEL_INFO = 3; this.LEVEL_WARN = 4; this.LEVEL_ERROR = 5; this.LEVEL_FATAL = 6;
/** * These are the font colors for each logging level.(定义各种错误的显示颜色) */ this.LEVEL_TRACE_COLOR = "a0a000"; this.LEVEL_DEBUG_COLOR = "64c864"; this.LEVEL_INFO_COLOR = "000000"; this.LEVEL_WARN_COLOR = "0000ff"; this.LEVEL_ERROR_COLOR = "ff8c00"; this.LEVEL_FATAL_COLOR = "ff0000";
/** * logLevel determines the minimum message level the instance will show.(需要显示的最小错误级别,默认为 3) */ this.logLevel = 3;
/** * targetDIV is the DIV object to output to. */ this.targetDiv = null;
/** * This function is used to set the minimum level a log instance will show. *(在这里定义需要显示的最小错误级别) * @param inLevel One of the level constants. Any message at this level * or a higher level will be displayed, others will not. */ this.setLevel = function(inLevel) {
this.logLevel = inLevel;
} // End setLevel().
/** * This function is used to set the target DIV that all messages are * written to. Note that when you call this, the DIV's existing contents * are cleared out.(设置信息显示的 DIV,调用此函数的时候,原有的信息将被清除) * * @param inTargetDiv The DIV object that all messages are written to. */ this.setTargetDiv = function(inTargetDiv) {
/** * This function is called to determine if a particular message meets or * exceeds the current level of the log instance and should therefore be * logged.(此函数用来判定现有的错误级别是否应该被显示) * * @param inLevel The level of the message being checked. */ this.shouldBeLogged = function(inLevel) {
/** * This function logs messages at TRACE level. *(格式化显示 TRACE 的错误级别信息,往依此类推) * @param inMessage The message to log. */ this.trace = function(inMessage) {
<a href="javascript:void(0);" id="enumPropsLink" onClick="jscript.debug.enumProps(document.getElementById('enumPropsLink'));"> enumProps()-Shows all the properties of this link(显示此链接标签对象的所有属性和值) </a> <br><br>
<div id="divLog" style="font-family:arial; font-size: 12pt; padding: 4px; background-color:#ffffff; border:1px solid #000000; width:50%; height:300px; overflow:scroll;">Log message will appear here</div> <script> var log = new jscript.debug.DivLogger(); log.setTargetDiv(document.getElementById("divLog")); log.setLevel(log.LEVEL_DEBUG); </script> <br> <a href="javascript:void(0);" onClick="log.trace('Were tracing along now');"> DivLogger.log.trace() - Try to add a TRACE message to the above DIV (won't work because it's below the specified DEBUG level); </a><br> <a href="javascript:void(0);" onClick="log.debug('Hmm, lets do some debugging');"> DivLogger.log.debug() - Try to add a DEBUG message to the above DIV </a><br> <a href="javascript:void(0);" onClick="log.info('Just for your information');"> DivLogger.log.info() - Add a INFO message to the above DIV </a><br> <a href="javascript:void(0);" onClick="log.warn('Warning! Danger Will Robinson!');"> DivLogger.log.warn() - Add a WARN message to the above DIV </a><br> <a href="javascript:void(0);" onClick="log.error('Dave, there is an error in the AE-35 module');"> DivLogger.log.error() - Add a ERROR message to the above DIV </a><br> <a href="javascript:void(0);" onClick="log.fatal('Game over man, game over!!');"> DivLogger.log.fatal() - Add a FATAL message to the above DIV </a><br> <br><br>
</div>
上面的测试代码里面的 <script> 段进行了 debug 的实例化,设置了显示信息的 DIV,而且设置了显示信息的最小级别为:LEVEL_DEBUG: var log = new jscript.debug.DivLogger(); log.setTargetDiv(document.getElementById("divLog")); log.setLevel(log.LEVEL_DEBUG); 来看看效果如何呢:
[Ctrl+A 全选 注:引入外部Js需再刷新一下页面才能执行] 在点击“enumProps()-Shows all ……”(第一个 link )的时候浏览器弹出的框如下图所示(Opera),详细地列出了你所点击的 a 标签对象的所有属性及值: