如何放置调试点

Question

I've a php file calling another php file which sometimes calls another php file to execute some actions (all through ajax).

What I use to do was to echo at different points to know upto where the codes are executing properly. But with this approach, I can keep echo-ing.

So how do I know upto where my code is executing?? Is there a tool for Google Chrome browser to detect it??

Answer 1

Firefox的Firebug插件可让您放置实际的调试断点并逐步执行代码-调试JavaScript比回显要容易得多

Answer 2

In your web browser, click the wrench icon, then "Tools", then "Developer tools". You can debug and step through JavaScript, you can see a timeline of requests with the request and response headers and bodies fully inspectable, etc. You should be able to debug all your AJAX request without any additional software/plugins.

Answer 3

If you look on how to set a debugging environent with PHP, you'll find a lot of dead ends, trust me, I did. Therefore you've got 2 choices.

A: Keep echo-ing which will leave a trail of painful echo's in your code.

B: Use a logger. I've used for a while FirePHP , which comes as a FireBug extension and lets you send debugging messages to the browser, which is ideal for debugging Javascript based apps with heavy Ajax.

Hope I can help!

Answer 4

The technique you're using is called bullet tracing. There's no real way to track which code executes and when within an php file (like breakpoints) but you can pinpoint points of errors on lines of code as provided by the php debugger.

When AJAX requests are made, you can track the progress through XMLHttpRequest States . To check the headers and payload of the packets being sent, you could use Firebug in Firefox 3.6.x, Firefox 4 Beta's built-in developer console, or Google Chrome's developer console. (Packet sniffers also work)