Struct ObservableProperty 

pub struct ObservableProperty<T> { /* private fields */ }

A thread-safe observable property that notifies observers when its value changes

This type wraps a value of type T and allows multiple observers to be notified whenever the value is modified. All operations are thread-safe and can be called from multiple threads concurrently.

Type Requirements

The generic type T must implement:

• Clone: Required for returning values and passing them to observers
• Send: Required for transferring between threads
• Sync: Required for concurrent access from multiple threads
• 'static: Required for observer callbacks that may outlive the original scope

Examples

use observable_property::ObservableProperty;
use std::sync::Arc;

let property = ObservableProperty::new("initial".to_string());

let observer_id = match property.subscribe(Arc::new(|old, new| {
    println!("Changed from '{}' to '{}'", old, new);
})) {
    Ok(id) => id,
    Err(e) => {
        eprintln!("Failed to subscribe observer: {}", e);
        return; // or handle error appropriately
    }
};

if let Err(e) = property.set("updated".to_string()) {
    eprintln!("Failed to set property value: {}", e);
} // Prints: Changed from 'initial' to 'updated'
 
if let Err(e) = property.unsubscribe(observer_id) {
    eprintln!("Failed to unsubscribe observer: {}", e);
}

Implementations

impl<T: Clone + Send + Sync + 'static> ObservableProperty<T>

pub fn new(initial_value: T) -> Self

Creates a new observable property with the given initial value

Arguments

• initial_value - The starting value for this property

Examples

use observable_property::ObservableProperty;

let property = ObservableProperty::new(42);
match property.get() {
    Ok(value) => assert_eq!(value, 42),
    Err(e) => eprintln!("Failed to get property value: {}", e),
}

Examples found in repository

examples/basic.rs (line 18)

    fn new(name: String, age: i32) -> Self {
        Self {
            name: ObservableProperty::new(name),
            age: ObservableProperty::new(age),
        }
    }

    fn get_name(&self) -> Result<String, observable_property::PropertyError> {
        self.name.get()
    }

    fn set_name(&self, new_name: String) -> Result<(), observable_property::PropertyError> {
        self.name.set(new_name)
    }

    fn get_age(&self) -> Result<i32, observable_property::PropertyError> {
        self.age.get()
    }

    fn set_age(&self, new_age: i32) -> Result<(), observable_property::PropertyError> {
        self.age.set(new_age)
    }

    fn celebrate_birthday(&self) -> Result<(), observable_property::PropertyError> {
        let current_age = self.age.get()?;
        self.age.set(current_age + 1)
    }
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    println!("=== Observable Property Basic Example ===\n");

    // Create a person
    let person = Person::new("Alice".to_string(), 25);

    // Subscribe to name changes
    let name_observer_id = person.name.subscribe(Arc::new(|old_name, new_name| {
        println!("📝 Name changed: '{}' → '{}'", old_name, new_name);
    }))?;

    // Subscribe to age changes
    let age_observer_id = person.age.subscribe(Arc::new(|old_age, new_age| {
        println!("🎂 Age changed: {} → {}", old_age, new_age);
    }))?;

    // Subscribe to only significant age changes (milestones)
    let milestone_observer_id = person.age.subscribe_filtered(
        Arc::new(|_old_age, new_age| {
            println!("🎉 Milestone reached! {} is now a special age: {}", 
                    if *new_age >= 18 { "Adult" } else { "Child" }, new_age);
        }),
        |old_age, new_age| {
            // Notify on milestone ages
            let milestones = [18, 21, 30, 40, 50, 65];
            milestones.contains(new_age) || 
            (milestones.contains(old_age) && !milestones.contains(new_age))
        }
    )?;

    println!("Initial state:");
    println!("  Name: {}", person.get_name()?);
    println!("  Age: {}\n", person.get_age()?);

    // Demonstrate property changes
    println!("Making changes...\n");

    // Change name
    person.set_name("Alice Johnson".to_string())?;

    // Age up a few times
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;

    // Change to milestone age
    person.set_age(21)?;

    // Direct property access
    println!("\nDirect property access:");
    let simple_property = ObservableProperty::new(100);
    
    simple_property.subscribe(Arc::new(|old, new| {
        println!("💰 Value changed: {} → {}", old, new);
    }))?;

    simple_property.set(200)?;
    simple_property.set(150)?;

    // Cleanup observers
    person.name.unsubscribe(name_observer_id)?;
    person.age.unsubscribe(age_observer_id)?;
    person.age.unsubscribe(milestone_observer_id)?;

    println!("\n✅ Example completed successfully!");
    Ok(())
}

examples/multithreaded.rs (line 16)

    fn new(name: String, age: i32) -> Self {
        Self {
            name: ObservableProperty::new(name),
            age: ObservableProperty::new(age),
        }
    }

pub fn get(&self) -> Result<T, PropertyError>

Gets the current value of the property

This method acquires a read lock, which allows multiple concurrent readers but will block if a writer currently holds the lock.

Returns

Ok(T) containing a clone of the current value, or Err(PropertyError) if the lock is poisoned.

Examples

use observable_property::ObservableProperty;

let property = ObservableProperty::new("hello".to_string());
match property.get() {
    Ok(value) => assert_eq!(value, "hello"),
    Err(e) => eprintln!("Failed to get property value: {}", e),
}

Examples found in repository

examples/basic.rs (line 24)

    fn get_name(&self) -> Result<String, observable_property::PropertyError> {
        self.name.get()
    }

    fn set_name(&self, new_name: String) -> Result<(), observable_property::PropertyError> {
        self.name.set(new_name)
    }

    fn get_age(&self) -> Result<i32, observable_property::PropertyError> {
        self.age.get()
    }

    fn set_age(&self, new_age: i32) -> Result<(), observable_property::PropertyError> {
        self.age.set(new_age)
    }

    fn celebrate_birthday(&self) -> Result<(), observable_property::PropertyError> {
        let current_age = self.age.get()?;
        self.age.set(current_age + 1)
    }

examples/multithreaded.rs (line 22)

    fn get_name(&self) -> Result<String, observable_property::PropertyError> {
        self.name.get()
    }

    fn set_name(&self, new_name: String) -> Result<(), observable_property::PropertyError> {
        self.name.set(new_name)
    }

    fn get_age(&self) -> Result<i32, observable_property::PropertyError> {
        self.age.get()
    }

    fn set_age(&self, new_age: i32) -> Result<(), observable_property::PropertyError> {
        self.age.set(new_age)
    }

    fn celebrate_birthday(&self) -> Result<(), observable_property::PropertyError> {
        let current_age = self.age.get()?;
        self.age.set(current_age + 1)
    }

pub fn set(&self, new_value: T) -> Result<(), PropertyError>

Sets the property to a new value and notifies all observers

This method will:

1. Acquire a write lock (blocking other readers/writers)
2. Update the value and capture a snapshot of observers
3. Release the lock
4. Notify all observers sequentially with the old and new values

Observer notifications are wrapped in panic recovery to prevent one misbehaving observer from affecting others.

Arguments

• new_value - The new value to set

Returns

Ok(()) if successful, or Err(PropertyError) if the lock is poisoned.

Examples

use observable_property::ObservableProperty;
use std::sync::Arc;

let property = ObservableProperty::new(10);
 
match property.subscribe(Arc::new(|old, new| {
    println!("Value changed from {} to {}", old, new);
})) {
    Ok(_) => println!("Observer subscribed successfully"),
    Err(e) => {
        eprintln!("Failed to subscribe observer: {}", e);
        return; // or handle error appropriately
    }
};

// Triggers observer notification
if let Err(e) = property.set(20) {
    eprintln!("Failed to set property value: {}", e);
}

Examples found in repository

examples/basic.rs (line 28)

    fn set_name(&self, new_name: String) -> Result<(), observable_property::PropertyError> {
        self.name.set(new_name)
    }

    fn get_age(&self) -> Result<i32, observable_property::PropertyError> {
        self.age.get()
    }

    fn set_age(&self, new_age: i32) -> Result<(), observable_property::PropertyError> {
        self.age.set(new_age)
    }

    fn celebrate_birthday(&self) -> Result<(), observable_property::PropertyError> {
        let current_age = self.age.get()?;
        self.age.set(current_age + 1)
    }
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    println!("=== Observable Property Basic Example ===\n");

    // Create a person
    let person = Person::new("Alice".to_string(), 25);

    // Subscribe to name changes
    let name_observer_id = person.name.subscribe(Arc::new(|old_name, new_name| {
        println!("📝 Name changed: '{}' → '{}'", old_name, new_name);
    }))?;

    // Subscribe to age changes
    let age_observer_id = person.age.subscribe(Arc::new(|old_age, new_age| {
        println!("🎂 Age changed: {} → {}", old_age, new_age);
    }))?;

    // Subscribe to only significant age changes (milestones)
    let milestone_observer_id = person.age.subscribe_filtered(
        Arc::new(|_old_age, new_age| {
            println!("🎉 Milestone reached! {} is now a special age: {}", 
                    if *new_age >= 18 { "Adult" } else { "Child" }, new_age);
        }),
        |old_age, new_age| {
            // Notify on milestone ages
            let milestones = [18, 21, 30, 40, 50, 65];
            milestones.contains(new_age) || 
            (milestones.contains(old_age) && !milestones.contains(new_age))
        }
    )?;

    println!("Initial state:");
    println!("  Name: {}", person.get_name()?);
    println!("  Age: {}\n", person.get_age()?);

    // Demonstrate property changes
    println!("Making changes...\n");

    // Change name
    person.set_name("Alice Johnson".to_string())?;

    // Age up a few times
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;

    // Change to milestone age
    person.set_age(21)?;

    // Direct property access
    println!("\nDirect property access:");
    let simple_property = ObservableProperty::new(100);
    
    simple_property.subscribe(Arc::new(|old, new| {
        println!("💰 Value changed: {} → {}", old, new);
    }))?;

    simple_property.set(200)?;
    simple_property.set(150)?;

    // Cleanup observers
    person.name.unsubscribe(name_observer_id)?;
    person.age.unsubscribe(age_observer_id)?;
    person.age.unsubscribe(milestone_observer_id)?;

    println!("\n✅ Example completed successfully!");
    Ok(())
}

examples/multithreaded.rs (line 26)

    fn set_name(&self, new_name: String) -> Result<(), observable_property::PropertyError> {
        self.name.set(new_name)
    }

    fn get_age(&self) -> Result<i32, observable_property::PropertyError> {
        self.age.get()
    }

    fn set_age(&self, new_age: i32) -> Result<(), observable_property::PropertyError> {
        self.age.set(new_age)
    }

    fn celebrate_birthday(&self) -> Result<(), observable_property::PropertyError> {
        let current_age = self.age.get()?;
        self.age.set(current_age + 1)
    }

pub fn set_async(&self, new_value: T) -> Result<(), PropertyError>

Sets the property to a new value and notifies observers asynchronously

This method is similar to set() but spawns observers in background threads for non-blocking operation. This is useful when observers might perform time-consuming operations.

Observers are batched into groups and each batch runs in its own thread to limit resource usage while still providing parallelism.

Arguments

• new_value - The new value to set

Returns

Ok(()) if successful, or Err(PropertyError) if the lock is poisoned. Note that this only indicates the property was updated successfully; observer execution happens asynchronously.

Examples

use observable_property::ObservableProperty;
use std::sync::Arc;
use std::time::Duration;

let property = ObservableProperty::new(0);
 
match property.subscribe(Arc::new(|old, new| {
    // This observer does slow work but won't block the caller
    std::thread::sleep(Duration::from_millis(100));
    println!("Slow observer: {} -> {}", old, new);
})) {
    Ok(_) => println!("Observer subscribed successfully"),
    Err(e) => {
        eprintln!("Failed to subscribe observer: {}", e);
        return; // or handle error appropriately
    }
};

// This returns immediately even though observer is slow
if let Err(e) = property.set_async(42) {
    eprintln!("Failed to set property value asynchronously: {}", e);
}

pub fn subscribe( &self, observer: Observer<T>, ) -> Result<ObserverId, PropertyError>

Subscribes an observer function to be called when the property changes

The observer function will be called with the old and new values whenever the property is modified via set() or set_async().

Arguments

• observer - A function wrapped in Arc that takes (&T, &T) parameters

Returns

Ok(ObserverId) containing a unique identifier for this observer, or Err(PropertyError) if the lock is poisoned.

Examples

use observable_property::ObservableProperty;
use std::sync::Arc;

let property = ObservableProperty::new(0);

let observer_id = match property.subscribe(Arc::new(|old_value, new_value| {
    println!("Property changed from {} to {}", old_value, new_value);
})) {
    Ok(id) => id,
    Err(e) => {
        eprintln!("Failed to subscribe observer: {}", e);
        return; // or handle error appropriately
    }
};

// Later, unsubscribe using the returned ID
if let Err(e) = property.unsubscribe(observer_id) {
    eprintln!("Failed to unsubscribe observer: {}", e);
}

Examples found in repository

examples/multithreaded.rs (lines 50-52)

fn main() -> Result<(), Box<dyn std::error::Error>> {
    println!("=== Observable Property Multithreaded Person Example ===\n");

    let person = Arc::new(Person::new("Bob".to_string(), 30));

    // Subscribe to name changes
    let name_observer_id = person.name.subscribe(Arc::new(|old_name, new_name| {
        println!("📝 Name changed: '{}' → '{}'", old_name, new_name);
    }))?;

    // Subscribe to age changes
    let age_observer_id = person.age.subscribe(Arc::new(|old_age, new_age| {
        println!("🎂 Age changed: {} → {}", old_age, new_age);
    }))?;

    // Spawn threads to update name and age concurrently
    let person_clone1 = person.clone();
    let handle1 = thread::spawn(move || {
        for i in 0..3 {
            let new_name = format!("Bob #{}", i + 1);
            person_clone1.set_name(new_name).unwrap();
            thread::sleep(Duration::from_millis(50));
        }
    });

    let person_clone2 = person.clone();
    let handle2 = thread::spawn(move || {
        for _ in 0..3 {
            person_clone2.celebrate_birthday().unwrap();
            thread::sleep(Duration::from_millis(30));
        }
    });

    handle1.join().unwrap();
    handle2.join().unwrap();

    println!("\nFinal state:");
    println!("  Name: {}", person.get_name()?);
    println!("  Age: {}", person.get_age()?);

    // Cleanup observers
    person.name.unsubscribe(name_observer_id)?;
    person.age.unsubscribe(age_observer_id)?;

    println!("\n✅ Multithreaded Person example completed successfully!");
    Ok(())
}

examples/basic.rs (lines 52-54)

fn main() -> Result<(), Box<dyn std::error::Error>> {
    println!("=== Observable Property Basic Example ===\n");

    // Create a person
    let person = Person::new("Alice".to_string(), 25);

    // Subscribe to name changes
    let name_observer_id = person.name.subscribe(Arc::new(|old_name, new_name| {
        println!("📝 Name changed: '{}' → '{}'", old_name, new_name);
    }))?;

    // Subscribe to age changes
    let age_observer_id = person.age.subscribe(Arc::new(|old_age, new_age| {
        println!("🎂 Age changed: {} → {}", old_age, new_age);
    }))?;

    // Subscribe to only significant age changes (milestones)
    let milestone_observer_id = person.age.subscribe_filtered(
        Arc::new(|_old_age, new_age| {
            println!("🎉 Milestone reached! {} is now a special age: {}", 
                    if *new_age >= 18 { "Adult" } else { "Child" }, new_age);
        }),
        |old_age, new_age| {
            // Notify on milestone ages
            let milestones = [18, 21, 30, 40, 50, 65];
            milestones.contains(new_age) || 
            (milestones.contains(old_age) && !milestones.contains(new_age))
        }
    )?;

    println!("Initial state:");
    println!("  Name: {}", person.get_name()?);
    println!("  Age: {}\n", person.get_age()?);

    // Demonstrate property changes
    println!("Making changes...\n");

    // Change name
    person.set_name("Alice Johnson".to_string())?;

    // Age up a few times
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;

    // Change to milestone age
    person.set_age(21)?;

    // Direct property access
    println!("\nDirect property access:");
    let simple_property = ObservableProperty::new(100);
    
    simple_property.subscribe(Arc::new(|old, new| {
        println!("💰 Value changed: {} → {}", old, new);
    }))?;

    simple_property.set(200)?;
    simple_property.set(150)?;

    // Cleanup observers
    person.name.unsubscribe(name_observer_id)?;
    person.age.unsubscribe(age_observer_id)?;
    person.age.unsubscribe(milestone_observer_id)?;

    println!("\n✅ Example completed successfully!");
    Ok(())
}

pub fn unsubscribe(&self, id: ObserverId) -> Result<bool, PropertyError>

Removes an observer by its ID

Arguments

• id - The observer ID returned by subscribe()

Returns

Ok(bool) where true means the observer was found and removed, false means no observer with that ID existed. Returns Err(PropertyError) if the lock is poisoned.

Examples

use observable_property::ObservableProperty;
use std::sync::Arc;

let property = ObservableProperty::new(0);
 
// First, subscribe an observer
let id = match property.subscribe(Arc::new(|_, _| {})) {
    Ok(id) => id,
    Err(e) => {
        eprintln!("Failed to subscribe observer: {}", e);
        return; // or handle error appropriately
    }
};

// Then unsubscribe it
match property.unsubscribe(id) {
    Ok(was_removed) => {
        assert!(was_removed); // Observer existed and was removed
    },
    Err(e) => eprintln!("Failed to unsubscribe observer: {}", e),
}

// Try unsubscribing again - should return false
match property.unsubscribe(id) {
    Ok(was_removed_again) => {
        assert!(!was_removed_again); // Observer no longer exists
    },
    Err(e) => eprintln!("Failed to unsubscribe observer: {}", e),
}

Examples found in repository

examples/multithreaded.rs (line 85)

fn main() -> Result<(), Box<dyn std::error::Error>> {
    println!("=== Observable Property Multithreaded Person Example ===\n");

    let person = Arc::new(Person::new("Bob".to_string(), 30));

    // Subscribe to name changes
    let name_observer_id = person.name.subscribe(Arc::new(|old_name, new_name| {
        println!("📝 Name changed: '{}' → '{}'", old_name, new_name);
    }))?;

    // Subscribe to age changes
    let age_observer_id = person.age.subscribe(Arc::new(|old_age, new_age| {
        println!("🎂 Age changed: {} → {}", old_age, new_age);
    }))?;

    // Spawn threads to update name and age concurrently
    let person_clone1 = person.clone();
    let handle1 = thread::spawn(move || {
        for i in 0..3 {
            let new_name = format!("Bob #{}", i + 1);
            person_clone1.set_name(new_name).unwrap();
            thread::sleep(Duration::from_millis(50));
        }
    });

    let person_clone2 = person.clone();
    let handle2 = thread::spawn(move || {
        for _ in 0..3 {
            person_clone2.celebrate_birthday().unwrap();
            thread::sleep(Duration::from_millis(30));
        }
    });

    handle1.join().unwrap();
    handle2.join().unwrap();

    println!("\nFinal state:");
    println!("  Name: {}", person.get_name()?);
    println!("  Age: {}", person.get_age()?);

    // Cleanup observers
    person.name.unsubscribe(name_observer_id)?;
    person.age.unsubscribe(age_observer_id)?;

    println!("\n✅ Multithreaded Person example completed successfully!");
    Ok(())
}

examples/basic.rs (line 105)

fn main() -> Result<(), Box<dyn std::error::Error>> {
    println!("=== Observable Property Basic Example ===\n");

    // Create a person
    let person = Person::new("Alice".to_string(), 25);

    // Subscribe to name changes
    let name_observer_id = person.name.subscribe(Arc::new(|old_name, new_name| {
        println!("📝 Name changed: '{}' → '{}'", old_name, new_name);
    }))?;

    // Subscribe to age changes
    let age_observer_id = person.age.subscribe(Arc::new(|old_age, new_age| {
        println!("🎂 Age changed: {} → {}", old_age, new_age);
    }))?;

    // Subscribe to only significant age changes (milestones)
    let milestone_observer_id = person.age.subscribe_filtered(
        Arc::new(|_old_age, new_age| {
            println!("🎉 Milestone reached! {} is now a special age: {}", 
                    if *new_age >= 18 { "Adult" } else { "Child" }, new_age);
        }),
        |old_age, new_age| {
            // Notify on milestone ages
            let milestones = [18, 21, 30, 40, 50, 65];
            milestones.contains(new_age) || 
            (milestones.contains(old_age) && !milestones.contains(new_age))
        }
    )?;

    println!("Initial state:");
    println!("  Name: {}", person.get_name()?);
    println!("  Age: {}\n", person.get_age()?);

    // Demonstrate property changes
    println!("Making changes...\n");

    // Change name
    person.set_name("Alice Johnson".to_string())?;

    // Age up a few times
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;

    // Change to milestone age
    person.set_age(21)?;

    // Direct property access
    println!("\nDirect property access:");
    let simple_property = ObservableProperty::new(100);
    
    simple_property.subscribe(Arc::new(|old, new| {
        println!("💰 Value changed: {} → {}", old, new);
    }))?;

    simple_property.set(200)?;
    simple_property.set(150)?;

    // Cleanup observers
    person.name.unsubscribe(name_observer_id)?;
    person.age.unsubscribe(age_observer_id)?;
    person.age.unsubscribe(milestone_observer_id)?;

    println!("\n✅ Example completed successfully!");
    Ok(())
}

pub fn subscribe_filtered<F>( &self, observer: Observer<T>, filter: F, ) -> Result<ObserverId, PropertyError>

where F: Fn(&T, &T) -> bool + Send + Sync + 'static,

Subscribes an observer that only gets called when a filter condition is met

This is useful for observing only specific types of changes, such as when a value increases or crosses a threshold.

Arguments

• observer - The observer function to call when the filter passes
• filter - A predicate function that receives (old_value, new_value) and returns bool

Returns

Ok(ObserverId) for the filtered observer, or Err(PropertyError) if the lock is poisoned.

Examples

use observable_property::ObservableProperty;
use std::sync::Arc;

let property = ObservableProperty::new(0);

// Only notify when value increases
let id = match property.subscribe_filtered(
    Arc::new(|old, new| println!("Value increased: {} -> {}", old, new)),
    |old, new| new > old
) {
    Ok(id) => id,
    Err(e) => {
        eprintln!("Failed to subscribe filtered observer: {}", e);
        return; // or handle error appropriately
    }
};

// Triggers observer (0 -> 10)
if let Err(e) = property.set(10) {
    eprintln!("Failed to set property value: {}", e);
}
 
// Does NOT trigger observer (10 -> 5)
if let Err(e) = property.set(5) {
    eprintln!("Failed to set property value: {}", e);
}
 
// Triggers observer (5 -> 15)
if let Err(e) = property.set(15) {
    eprintln!("Failed to set property value: {}", e);
}

Examples found in repository

examples/basic.rs (lines 62-73)

fn main() -> Result<(), Box<dyn std::error::Error>> {
    println!("=== Observable Property Basic Example ===\n");

    // Create a person
    let person = Person::new("Alice".to_string(), 25);

    // Subscribe to name changes
    let name_observer_id = person.name.subscribe(Arc::new(|old_name, new_name| {
        println!("📝 Name changed: '{}' → '{}'", old_name, new_name);
    }))?;

    // Subscribe to age changes
    let age_observer_id = person.age.subscribe(Arc::new(|old_age, new_age| {
        println!("🎂 Age changed: {} → {}", old_age, new_age);
    }))?;

    // Subscribe to only significant age changes (milestones)
    let milestone_observer_id = person.age.subscribe_filtered(
        Arc::new(|_old_age, new_age| {
            println!("🎉 Milestone reached! {} is now a special age: {}", 
                    if *new_age >= 18 { "Adult" } else { "Child" }, new_age);
        }),
        |old_age, new_age| {
            // Notify on milestone ages
            let milestones = [18, 21, 30, 40, 50, 65];
            milestones.contains(new_age) || 
            (milestones.contains(old_age) && !milestones.contains(new_age))
        }
    )?;

    println!("Initial state:");
    println!("  Name: {}", person.get_name()?);
    println!("  Age: {}\n", person.get_age()?);

    // Demonstrate property changes
    println!("Making changes...\n");

    // Change name
    person.set_name("Alice Johnson".to_string())?;

    // Age up a few times
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;
    person.celebrate_birthday()?;

    // Change to milestone age
    person.set_age(21)?;

    // Direct property access
    println!("\nDirect property access:");
    let simple_property = ObservableProperty::new(100);
    
    simple_property.subscribe(Arc::new(|old, new| {
        println!("💰 Value changed: {} → {}", old, new);
    }))?;

    simple_property.set(200)?;
    simple_property.set(150)?;

    // Cleanup observers
    person.name.unsubscribe(name_observer_id)?;
    person.age.unsubscribe(age_observer_id)?;
    person.age.unsubscribe(milestone_observer_id)?;

    println!("\n✅ Example completed successfully!");
    Ok(())
}

Trait Implementations

impl<T: Clone> Clone for ObservableProperty<T>

fn clone(&self) -> Self

Creates a new reference to the same observable property

This creates a new ObservableProperty instance that shares the same underlying data with the original. Changes made through either instance will be visible to observers subscribed through both instances.

Examples

use observable_property::ObservableProperty;
use std::sync::Arc;

let property1 = ObservableProperty::new(42);
let property2 = property1.clone();

match property2.subscribe(Arc::new(|old, new| {
    println!("Observer on property2 saw change: {} -> {}", old, new);
})) {
    Ok(_) => println!("Observer subscribed successfully"),
    Err(e) => {
        eprintln!("Failed to subscribe observer: {}", e);
        return; // or handle error appropriately
    }
};

// This change through property1 will trigger the observer on property2
if let Err(e) = property1.set(100) {
    eprintln!("Failed to set property value: {}", e);
}

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Clone + Debug + Send + Sync + 'static> Debug for ObservableProperty<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Debug implementation that shows the current value if accessible