uCalc API Version: 5.7.0-preview.1 Released: 7/30/2026

Warning

uCalc API Preview Release Notice:This preview documentation describes the intended behavior of the API. It is not fully accurate or complete.The current preview build contains incomplete features, unoptimized performance, and is subject to breaking changes.Use of the preview version in your production code is not recommended.

Active = [bool]

Property

Product: 

Transformer Library

Class: 

Rule

Gets or sets a value indicating whether the rule is active and will be considered during pattern matching operations.

Remarks

The Active property provides a way to enable or disable a Rule at runtime without permanently deleting it. When a rule is inactive (false), the Transformer will completely ignore it during a Find(), Filter(), or Transform() operation.

This is a powerful feature for dynamically changing the behavior of a parser or for managing different sets of rules for different modes of operation.

⚙️ Getter and Setter Behavior

This property functions as both a getter and a setter:

  • Getter: var isActive = myRule.Active;Returns true if the rule is active (the default), and false if it has been disabled.

  • Setter: myRule.Active = false;Sets the active state of the rule. This (SetActive() method in VB and C#, or Active() in C++) returns the Rule object itself, allowing for a fluent, chainable syntax.

⚠️ Re-evaluation is Required

It is crucial to understand that changing a rule's Active state does not immediately affect the results of a previous transformation. You must call Find(), Filter(), or Transform() again to re-evaluate the input text with the updated rule set.

Active vs. Release() vs. Focusable()

Choose the right tool for managing a rule's lifecycle:

MethodPurposeStateReversibility
@Active(false)Temporarily disable a rule.The rule's definition is preserved in memory.Fully reversible by calling @Active(true).
Release()Permanently delete a rule.The rule is removed from memory and its resources are freed.Irreversible. The rule must be redefined.
@Focusable(false)Visually filter a rule's matches from the result list.The rule remains active and participates in matching, but its results can be hidden.Fully reversible. Does not require a re-scan.

💡 Why uCalc? (Comparative Analysis)

In most regex-based systems, "disabling" a pattern is not a built-in feature. A developer would typically have to:

  1. Store regex patterns as strings.
  2. Programmatically build a final "master" regex string by concatenating only the active patterns.
  3. Recompile the entire master regex object whenever the active set changes.

This is verbose, inefficient, and error-prone, especially when dealing with complex patterns.

uCalc's Active property provides a declarative, high-performance alternative. You define all your rules once, and then simply toggle their state with a boolean flag. The engine handles the complexity of ignoring inactive rules efficiently, leading to cleaner, more maintainable, and more dynamic code.

Examples

Demonstrates the basic toggle functionality of the Active property.

ID: 862

See: Active = [bool] 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();
string UserText = "The cat saw another cat.";
t.Text = UserText;

// Define a rule and hold its handle
var catRule = t.FromTo("cat", "dog");

Console.Write("1. Rule Active (Default): ");
Console.WriteLine(t.Transform());

// Deactivate the rule
catRule.Active = false;

// Re-run the transform to see the change
Console.Write("2. Rule Inactive: ");
t.Text = UserText;
Console.WriteLine(t.Transform());

// Reactivate the rule
catRule.Active = true;
Console.Write("3. Rule Reactivated: ");
Console.WriteLine(t.Transform());
				
			
1. Rule Active (Default): The dog saw another dog.
2. Rule Inactive: The cat saw another cat.
3. Rule Reactivated: The dog saw another dog.
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();
   string UserText = "The cat saw another cat.";
   t.Text(UserText);

   // Define a rule and hold its handle
   auto catRule = t.FromTo("cat", "dog");

   cout << "1. Rule Active (Default): ";
   cout << t.Transform() << endl;

   // Deactivate the rule
   catRule.Active(false);

   // Re-run the transform to see the change
   cout << "2. Rule Inactive: ";
   t.Text(UserText);
   cout << t.Transform() << endl;

   // Reactivate the rule
   catRule.Active(true);
   cout << "3. Rule Reactivated: ";
   cout << t.Transform() << endl;
}
				
			
1. Rule Active (Default): The dog saw another dog.
2. Rule Inactive: The cat saw another cat.
3. Rule Reactivated: The dog saw another dog.
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      Dim UserText As String = "The cat saw another cat."
      t.Text = UserText
      
      '// Define a rule and hold its handle
      Dim catRule = t.FromTo("cat", "dog")
      
      Console.Write("1. Rule Active (Default): ")
      Console.WriteLine(t.Transform())
      
      '// Deactivate the rule
      catRule.Active = false
      
      '// Re-run the transform to see the change
      Console.Write("2. Rule Inactive: ")
      t.Text = UserText
      Console.WriteLine(t.Transform())
      
      '// Reactivate the rule
      catRule.Active = true
      Console.Write("3. Rule Reactivated: ")
      Console.WriteLine(t.Transform())
   End Sub
End Module
				
			
1. Rule Active (Default): The dog saw another dog.
2. Rule Inactive: The cat saw another cat.
3. Rule Reactivated: The dog saw another dog.
Explore 600+ other examples
How to dynamically enable or disable transformation rules using the Active property.

ID: 120

See: Active = [bool], Active(bool) 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();
t.Str("<h3>Title</h3><b>Bold statement</b><h3>Title B</h3><b>Other text</b>");

var BoldTag = t.Pattern("<b>{text}</b>");
var H3Tag = t.Pattern("<h3>{text}</h3>");
t.Find();


Console.WriteLine(t.Matches.Text);
Console.WriteLine("");

BoldTag.Active = false;
Console.WriteLine($"BoldTag.Active(): {BoldTag.Active}");
Console.WriteLine("-----------------------");
t.Find();
Console.WriteLine(t.Matches.Text);
Console.WriteLine("");

BoldTag.Active = true;
Console.WriteLine($"BoldTag.Active(): {BoldTag.Active}");
Console.WriteLine("----------------------");

t.Find();
Console.WriteLine(t.Matches.Text);
Console.WriteLine("");

				
			
<h3>Title</h3>
<b>Bold statement</b>
<h3>Title B</h3>
<b>Other text</b>

BoldTag.Active(): False
-----------------------
<h3>Title</h3>
<h3>Title B</h3>

BoldTag.Active(): True
----------------------
<h3>Title</h3>
<b>Bold statement</b>
<h3>Title B</h3>
<b>Other text</b>
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

#define tf(IsTrue) ((IsTrue) ? "True" : "False")

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();
   t.Str("<h3>Title</h3><b>Bold statement</b><h3>Title B</h3><b>Other text</b>");

   auto BoldTag = t.Pattern("<b>{text}</b>");
   auto H3Tag = t.Pattern("<h3>{text}</h3>");
   t.Find();


   cout << t.Matches().Text() << endl;
   cout << "" << endl;

   BoldTag.Active(false);
   cout << "BoldTag.Active(): " << tf(BoldTag.Active()) << endl;
   cout << "-----------------------" << endl;
   t.Find();
   cout << t.Matches().Text() << endl;
   cout << "" << endl;

   BoldTag.Active(true);
   cout << "BoldTag.Active(): " << tf(BoldTag.Active()) << endl;
   cout << "----------------------" << endl;

   t.Find();
   cout << t.Matches().Text() << endl;
   cout << "" << endl;

}
				
			
<h3>Title</h3>
<b>Bold statement</b>
<h3>Title B</h3>
<b>Other text</b>

BoldTag.Active(): False
-----------------------
<h3>Title</h3>
<h3>Title B</h3>

BoldTag.Active(): True
----------------------
<h3>Title</h3>
<b>Bold statement</b>
<h3>Title B</h3>
<b>Other text</b>
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      t.Str("<h3>Title</h3><b>Bold statement</b><h3>Title B</h3><b>Other text</b>")
      
      Dim BoldTag = t.Pattern("<b>{text}</b>")
      Dim H3Tag = t.Pattern("<h3>{text}</h3>")
      t.Find()
      
      
      Console.WriteLine(t.Matches.Text)
      Console.WriteLine("")
      
      BoldTag.Active = false
      Console.WriteLine($"BoldTag.Active(): {BoldTag.Active}")
      Console.WriteLine("-----------------------")
      t.Find()
      Console.WriteLine(t.Matches.Text)
      Console.WriteLine("")
      
      BoldTag.Active = true
      Console.WriteLine($"BoldTag.Active(): {BoldTag.Active}")
      Console.WriteLine("----------------------")
      
      t.Find()
      Console.WriteLine(t.Matches.Text)
      Console.WriteLine("")
      
   End Sub
End Module
				
			
<h3>Title</h3>
<b>Bold statement</b>
<h3>Title B</h3>
<b>Other text</b>

BoldTag.Active(): False
-----------------------
<h3>Title</h3>
<h3>Title B</h3>

BoldTag.Active(): True
----------------------
<h3>Title</h3>
<b>Bold statement</b>
<h3>Title B</h3>
<b>Other text</b>
Explore 600+ other examples
Toggling a rule on and off.

ID: 885

See: Active = [bool], Rules 
				
					using uCalcSoftware;

var uc = new uCalc();
var t = uc.NewTransformer();
var r = t.FromTo("Hello", "Hi");

// Disable
r.Active = false;
Console.WriteLine(t.Transform("Hello").Text); // Output: Hello (No change)

// Enable
r.Active = true;
Console.WriteLine(t.Transform("Hello").Text); // Output: Hi
				
			
Hello
Hi
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto t = uc.NewTransformer();
   auto r = t.FromTo("Hello", "Hi");

   // Disable
   r.Active(false);
   cout << t.Transform("Hello").Text() << endl; // Output: Hello (No change)

   // Enable
   r.Active(true);
   cout << t.Transform("Hello").Text() << endl; // Output: Hi
}
				
			
Hello
Hi
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim t = uc.NewTransformer()
      Dim r = t.FromTo("Hello", "Hi")
      
      '// Disable
      r.Active = false
      Console.WriteLine(t.Transform("Hello").Text) '// Output: Hello (No change)
      
      '// Enable
      r.Active = true
      Console.WriteLine(t.Transform("Hello").Text) '// Output: Hi
   End Sub
End Module
				
			
Hello
Hi
Explore 600+ other examples