live_cells_core 0.18.2

live_cells_core: ^0.18.2 copied to clipboard

• Add .withDefault() and .onTrigger methods for handling EmptyMetaCellError.

• Add key argument to ActionCell constructor.

New features:

• Meta Cells

  A meta cell (MetaCell) is a cell that points to another cell. The value of a meta cell is the value of the pointed to cell, and its observers are notified when the pointed to cell's value changes.

  The pointed to cell can be changed multiple times.

  Example:

  final a = MutableCell(0);
  final b = MutableCell(1);
    
  final meta = MetaCell<int>();
    
  meta.setCell(a);
  print(meta.value); // 0
    
  meta.setCell(b);
  print(meta.value); // 1
  

• The .hold() method for keeping a cell active until it is released with .release()

  final a = MutableCell(0, key: aKey);
    
  // Ensure that a is active
  final hold = a.hold();
  ...
  // Allow a to be disposed
  hold.release();
  

Breaking Changes:

• Removed dispose() method from MutableCell interface.

• Reading/writing the value of a keyed MutableCell while it is inactive now throws an InactivePersistentStatefulCellError.

  Use .hold() to ensure a keyed MutableCell is active before using it.

New features:

• Functionality for automatically generating cell keys, using AutoKey.
• Mutable cells can now have keys.

• Add exception handling in initial call to cell watch functions.
• Improve unhandled exception notices.

New features:

• and(), or() and not() now return keyed cells.

• The following methods for waiting for changes in cell values:

  • .nextChange()
  • .untilValue()
  • .untilTrue()
  • .untilFalse()

• ActionCell

  A cell without a value, used solely to represent actions and events.

• Fix issue with .isCompleted having incorrect value when Future completes with an error.

New features:

• .awaited property on cells holding a Future.

  Returns a cell which evaluates to the value of the Future when completed, throws an UninitializedCellError when it is pending.

• .isCompleted property on cells holding a Future.

  Returns a cell which evaluates to true when the Future is complete, false while it is pending.

• .initialValue(...) which returns a cell with takes on the value of the given cell until it is initialized.

Minor additions:

• .waitLast property which is the same as .wait but if a new Future is recevied before the previous one has resolved, the previous value update is dropped.

New features for asynchronous cells:

• .wait property for creating a cell that awaits a Future held in another cell.
• .delayed for creating a cell that takes the value of another cell but only notifies its observers after a given delay.

Breaking changes:

• Removed DelayCell.

• .cell extension property is now available on all types
• Additions to Iterable cell extension:
  • cast<E>() method
  • map() method
• Additions to List cell extension:
  • cast<E>() method
  • mapCells() method

• Fix potential issues when the computed value of a mutable computed cell is the same as its assigned value.

• Fix issue with recomputing the value of mutable computed cells.

• Reduce minimum version of meta dependency

New features:

• Record extension methods for creating lightweight computed (and mutable computed) cells:

  (a, b).apply((a,b) => a + b);
  (a, b).mutableApply((a,b) => a + b, (v) {...});
  

• changesOnly option in cell constructors. When this option is set to true, the cell only notifies its observers when its value has actually changed.

• Relaxed restriction that MutableCellView only accept a single argument

• Extensions which allow Iterable, List, Map and Set methods and properties to be used directly on cells:

  ValueCell<List<int>> listCell;
  ValueCell<int> index;
  ... 
  final elementI = listCell[index];
  final length = listCell.length;
  

Breaking changes:

• CellObserver.update now takes a second didChange parameter. This only affects code that uses the CellObserver interface directly.
• DependentCell, ComputeCell and MutableCellView now take an argument Set as opposed to an argument List. This only affects code which instantiates these classes directly.
• Remove CellListenableExtension. This will be moved to the live_cell_widgets package.

Other changes:

• Removed dependency on Flutter. This package can now be used in pure Dart applications.
• Deprecated ListComputeExtension, i.e. [a, b].computeCell(...). Use the record compute extensions instead.

• Core live cell definitions extracted from live_cells package to this package.