progress july 11 - store/selection to object list

src/app/shared/object-list/selectable-list/selectable-list.reducer.ts

@@ -0,0 +1,106 @@
+import { ListableObject } from '../../object-collection/shared/listable-object.model';
+import {
+  SelectableListAction,
+  SelectableListActionTypes,
+  SelectableListSelectAction,
+  SelectableListSelectSingleAction,
+  SelectableListDeselectAction,
+  SelectableListDeselectSingleAction, SelectableListSetSelectionAction
+} from './selectable-list.actions';
+import { hasNoValue } from '../../empty.util';
+
+/**
+ * Represents the state of all selectable lists in the store
+ */
+export type SelectableListsState = {
+  [id: string]: SelectableListState;
+}
+
+/**
+ * Represents the state of a single selectable list in the store
+ */
+export interface SelectableListState {
+  id: string;
+  selection: ListableObject[];
+}
+
+/**
+ * Reducer that handles SelectableListAction to update the SelectableListsState
+ * @param {SelectableListsState} state The initial SelectableListsState
+ * @param {SelectableListAction} action The Action to be performed on the state
+ * @returns {SelectableListsState} The new, reducer SelectableListsState
+ */
+export function selectableListReducer(state: SelectableListsState = {}, action: SelectableListAction): SelectableListsState {
+  const listState: SelectableListState = state[action.id] || clearSelection(action.id);
+  switch (action.type) {
+    case SelectableListActionTypes.SELECT: {
+      const newListState = select(listState, action as SelectableListSelectAction);
+      return Object.assign({}, state, { [action.id]: newListState });
+    }
+    case SelectableListActionTypes.SELECT_SINGLE: {
+      const newListState = selectSingle(listState, action as SelectableListSelectSingleAction);
+      return Object.assign({}, state, { [action.id]: newListState });
+    }
+    case SelectableListActionTypes.DESELECT: {
+      const newListState = deselect(listState, action as SelectableListDeselectAction);
+      return Object.assign({}, state, { [action.id]: newListState });
+    }
+    case SelectableListActionTypes.DESELECT_SINGLE: {
+      const newListState = deselectSingle(listState, action as SelectableListDeselectSingleAction);
+      return Object.assign({}, state, { [action.id]: newListState });
+    }
+    case SelectableListActionTypes.SET_SELECTION: {
+      const newListState = setList(listState, action as SelectableListSetSelectionAction);
+      return Object.assign({}, state, { [action.id]: newListState });
+    }
+    case SelectableListActionTypes.DESELECT_ALL: {
+      const newListState = clearSelection(action.id);
+      return Object.assign({}, state, { [action.id]: newListState });
+    }
+    default: {
+      return state;
+    }
+  }
+}
+
+function select(state: SelectableListState, action: SelectableListSelectAction) {
+  const filteredNewObjects = action.payload.filter((object) => !isObjectInSelection(state.selection, object));
+  const newSelection = [...state.selection, ...filteredNewObjects];
+  return Object.assign({}, state, { selection: newSelection });
+}
+
+function selectSingle(state: SelectableListState, action: SelectableListSelectSingleAction) {
+  let newSelection;
+  if (action.payload.multipleSelectionsAllowed && !isObjectInSelection(state.selection, action.payload)) {
+    newSelection = [...state.selection, action.payload.object];
+  } else {
+    newSelection = [action.payload.object];
+  }
+  return Object.assign({}, state, { selection: newSelection });
+}
+
+function deselect(state: SelectableListState, action: SelectableListDeselectAction) {
+  const newSelection = state.selection.filter((selected) => hasNoValue(action.payload.find((object) => object === selected)));
+  return Object.assign({}, state, { selection: newSelection });
+}
+
+function deselectSingle(state: SelectableListState, action: SelectableListDeselectSingleAction) {
+  const newSelection = state.selection.filter((selected) => {
+    return selected !== action.payload
+  });
+  return Object.assign({}, state, { selection: newSelection });
+}
+
+function setList(state: SelectableListState, action: SelectableListSetSelectionAction) {
+  const newSelection = [...state.selection, action.payload];
+  return Object.assign({}, state, { selection: newSelection });
+}
+
+function clearSelection(id: string) {
+  return { id: id, selection: [] };
+}
+
+
+function isObjectInSelection(selection: ListableObject[], object: ListableObject) {
+  return selection.findIndex((selected) => selected === object) >= 0
+}