How to retrieve PHP backtrace summary in WordPress
The WordPress function wp_debug_backtrace_summary is a debugging tool that returns a concise summary of the backtrace. The backtrace is a list of all the function calls made up to the point where the function is called. This function provides a snapshot of the function call stack, which can be useful for identifying the sequence of function calls leading up to a specific point in the code.
By using wp_debug_backtrace_summary, developers can gain insights into the flow of execution and identify potential issues or bottlenecks in their code. This function is especially useful in complex applications where the flow of execution can be difficult to track. It can help developers understand how different parts of the application interact, and can be instrumental in debugging and optimizing the code.
It’s important to note that the wp_debug_backtrace_summary function does not alter the program’s state or affect its execution in any way. It simply provides a summary of the function call stack for debugging purposes.
Parameters
The wp_debug_backtrace_summary function in WordPress accepts three parameters which are described below:
$ignore_class(string): This is an optional parameter whose default value is null. It is used to specify a class from which all function calls will be ignored. This is particularly helpful when you want to provide information only about the calling function.$skip_frames(int): Another optional parameter that helps to skip a certain number of stack frames. The default value is 0. This is beneficial when you need to trace back to the origin of the issue.$pretty(bool): This is also an optional parameter with a default value of true. It determines whether the output should be a comma-separated string instead of the default raw array.
Return Value
The wp_debug_backtrace_summary function returns either a string or an array. If a string is returned, it will be a reversed comma-separated trace. If an array is returned, it will consist of individual calls.
If the function does not accept any parameters, this will be explicitly stated.
Examples
How to use wp_debug_backtrace_summary to get a comma separated string of the call stack
The following code snippet demonstrates how to use the wp_debug_backtrace_summary function to get a comma separated string of the call stack.
function debug_backtrace_example() {
$backtrace = wp_debug_backtrace_summary();
echo '<p>' . $backtrace . '</p>';
}
debug_backtrace_example();
How to use wp_debug_backtrace_summary to get an array of the call stack
The following code snippet demonstrates how to use the wp_debug_backtrace_summary function to get an array of the call stack. Here we set the third parameter, $pretty, to false.
function debug_backtrace_example() {
$backtrace = wp_debug_backtrace_summary(null, 0, false);
echo '<pre>';
print_r($backtrace);
echo '</pre>';
}
debug_backtrace_example();
How to use wp_debug_backtrace_summary to ignore calls within a specific class
The following code snippet demonstrates how to use the wp_debug_backtrace_summary function to ignore all function calls within a specific class. Here we set the first parameter, $ignore_class, to the class name we want to ignore.
function debug_backtrace_example() {
$backtrace = wp_debug_backtrace_summary('ClassNameToIgnore');
echo '<p>' . $backtrace . '</p>';
}
debug_backtrace_example();
Conclusion
The wp_debug_backtrace_summary function in WordPress is a tool which provides a snapshot of the function call stack at any given point in time. It can be leveraged by developers for debugging purposes, as it displays a summary of the current function calls, the file they are located in, and the line number from where they were called. This can be particularly beneficial in identifying the source of errors or anomalies within the code, thereby assisting in timely resolution of issues and ensuring the smooth operation of the WordPress site.