General:
- Use CommonJS idioms to be compatible with Browserify
- NPM packaging and versioning
- Tests ???
Model features:
- Implement isolated nodes.
- A more convenient node registry.
- JSON serialization.
- Move all model updates to editor-level instead of surface-level (actually, the need for a "level" was removed, transforms and behavior functions are now functions without context).
- Clearly separate and/or re-organize event handlers, model transforms and base commands.
- Full UTF-8 support.
- Editor destruction.
UI features:
- Implement a toolbar.
- Keyboard shortcuts (associated to toolbar buttons)
- Support copy/paste.
- Implement annotations and styles ! Bold, italics, etc.
- Maybe support additional keys like delete, tab, shift+enter, etc.
Behavior function: A transformation function that takes a range as first argument, and a DOM event as second optional argument. They can handle critical inputs (in which case the DOM event is provided, and they have side-effects on the selection) or be used as normal transformation functions.
Command: A cancellable operation that updates the model. It can be thought of as a set of two functions, execute and cancel, that take the current document state and return a new one (but in fact, the state is muted, not replaced).
Critical inputs: Inputs from the user that are handled by default by contentEditable in a way that will certainly break the mapping rules between document model and DOM. For example: enter, backspace, delete, paste…
Model/Document node: A document's building block; could represent a paragraph for example.
Node: Might be DOM node or model node.
Range: A continuous portion of the document selected by the user. It is delimited by two points, a start and an end, which are successive in reading direction. It is always associated to one surface.
Selection: A range selected by the user. Technically, there is always a selection as the caret is represented by a selection with identical start and end.
Surface: An object associated to a unique DOM element whose contenteditable property is set to true. All model nodes are represented by DOM nodes inside the surface.
Surface hierarchy: See dedicated section.
Surface node: A DOM node that is a direct child of the Surface DOM element.
Transformation function: A function that returns a command. They can also be called "transforms".
The editor consists of one main surface; but inside this surface, some nodes can integrate surfaces themselves. We call these child surfaces and the main surface can also be called the mother surface.
For practical reasons (performance and simplicity of code), this hierarchy is limited to two levels. On the first level can only sit the mother surface; child surfaces sit on the second level.
Indeed, if, when handling selection, the anchor and focus points belong to different surfaces, the handling of critical inputs must be delegated to their lowest common ancestor. However, we didn't want to implement an algorithm to compute that just to handle selection… Limiting the surface hierarchy ensures that the lowest common ancestor be always the mother surface, plus who would need a surface imbricated in a surface itself imbricated in the main surface ?