Active-GO/core/errs/try_catch.go

// =============================================================================
//  Active-GO Framework
//  Copyright (c) 2024 ActiveThing (https://activething.com)
//  Author: Juan V. Navarro juanvnl@activething.com
// =============================================================================
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
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//  copies of the Software, and to permit persons to whom the Software is
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//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
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//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// =============================================================================

package errs

// TryCatch struct defines the structure for handling Try-Catch-Finally operations.
// - Try: A function that will be executed in the "try" block.
// - Catch: A function that will be executed if a panic occurs in the "try" block (catching the panic).
// - Finally: A function that will be executed at the end of the execution, regardless of success or failure (finally block).
type TryCatch struct {
	Try     func(params ...any) // Function to execute in the "try" block
	Catch   func(err error)     // Function to handle errors if a panic occurs (catch block)
	Finally func(params ...any) // Function to execute in the "finally" block (always runs)
}

// Do executes the Try, Catch, and Finally blocks based on the provided parameters.
// It will:
// 1. Execute the Try block.
// 2. Catch any panics that occur during the Try block execution and pass them to the Catch block.
// 3. Always execute the Finally block at the end, whether an error occurred or not.
func (c TryCatch) Do(params ...any) {
	// If a Finally block is provided, defer its execution to ensure it runs last.
	if c.Finally != nil {
		defer c.Finally(params...)
	}

	ok := false // A flag to ensure the Catch block is only executed once.

	// If a Catch block is provided, defer a function that recovers from panics.
	// The recovery will invoke the Catch block if a panic occurs.
	if c.Catch != nil {
		defer func(done *bool) {
			if !(*done) { // Ensure the Catch block is only executed once.
				if rc := recover(); rc != nil { // If a panic occurred, handle it.
					c.Catch(*NewErrPanic(ToError(rc))) // Pass the recovered value (converted to error) to the Catch block.
				}
			}
		}(&ok)
	}

	// Execute the Try block.
	c.Try(params...)

	// Mark the flag as true to indicate the Try block has completed without triggering a panic.
	ok = true
}