2018-10-25 12:58:40 -04:00

240 lines
8.7 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {devModeEqual} from '../change_detection/change_detection_util';
import {assertDefined, assertLessThan} from './assert';
import {ACTIVE_INDEX, LContainer} from './interfaces/container';
import {LContext, MONKEY_PATCH_KEY_NAME} from './interfaces/context';
import {ComponentDef, DirectiveDef} from './interfaces/definition';
import {NO_PARENT_INJECTOR, RelativeInjectorLocation, RelativeInjectorLocationFlags} from './interfaces/injector';
import {TContainerNode, TElementNode, TNode, TNodeFlags} from './interfaces/node';
import {RComment, RElement, RText} from './interfaces/renderer';
import {StylingContext} from './interfaces/styling';
import {CONTEXT, DECLARATION_VIEW, FLAGS, HEADER_OFFSET, HOST, HOST_NODE, LViewData, LViewFlags, PARENT, RootContext, TData, TVIEW} from './interfaces/view';
/**
* Returns whether the values are different from a change detection stand point.
*
* Constraints are relaxed in checkNoChanges mode. See `devModeEqual` for details.
*/
export function isDifferent(a: any, b: any, checkNoChangesMode: boolean): boolean {
if (ngDevMode && checkNoChangesMode) {
return !devModeEqual(a, b);
}
// NaN is the only value that is not equal to itself so the first
// test checks if both a and b are not NaN
return !(a !== a && b !== b) && a !== b;
}
export function stringify(value: any): string {
if (typeof value == 'function') return value.name || value;
if (typeof value == 'string') return value;
if (value == null) return '';
return '' + value;
}
/**
* Flattens an array in non-recursive way. Input arrays are not modified.
*/
export function flatten(list: any[]): any[] {
const result: any[] = [];
let i = 0;
while (i < list.length) {
const item = list[i];
if (Array.isArray(item)) {
if (item.length > 0) {
list = item.concat(list.slice(i + 1));
i = 0;
} else {
i++;
}
} else {
result.push(item);
i++;
}
}
return result;
}
/** Retrieves a value from any `LViewData` or `TData`. */
export function loadInternal<T>(index: number, arr: LViewData | TData): T {
ngDevMode && assertDataInRangeInternal(index + HEADER_OFFSET, arr);
return arr[index + HEADER_OFFSET];
}
export function assertDataInRangeInternal(index: number, arr: any[]) {
assertLessThan(index, arr ? arr.length : 0, 'index expected to be a valid data index');
}
/**
* Takes the value of a slot in `LViewData` and returns the element node.
*
* Normally, element nodes are stored flat, but if the node has styles/classes on it,
* it might be wrapped in a styling context. Or if that node has a directive that injects
* ViewContainerRef, it may be wrapped in an LContainer. Or if that node is a component,
* it will be wrapped in LViewData. It could even have all three, so we keep looping
* until we find something that isn't an array.
*
* @param value The initial value in `LViewData`
*/
export function readElementValue(value: RElement | StylingContext | LContainer | LViewData):
RElement {
while (Array.isArray(value)) {
value = value[HOST] as any;
}
return value;
}
/**
* Retrieves an element value from the provided `viewData`, by unwrapping
* from any containers, component views, or style contexts.
*/
export function getNativeByIndex(index: number, arr: LViewData): RElement {
return readElementValue(arr[index + HEADER_OFFSET]);
}
export function getNativeByTNode(tNode: TNode, hostView: LViewData): RElement|RText|RComment {
return readElementValue(hostView[tNode.index]);
}
export function getTNode(index: number, view: LViewData): TNode {
return view[TVIEW].data[index + HEADER_OFFSET] as TNode;
}
export function getComponentViewByIndex(nodeIndex: number, hostView: LViewData): LViewData {
// Could be an LViewData or an LContainer. If LContainer, unwrap to find LViewData.
const slotValue = hostView[nodeIndex];
return slotValue.length >= HEADER_OFFSET ? slotValue : slotValue[HOST];
}
export function isContentQueryHost(tNode: TNode): boolean {
return (tNode.flags & TNodeFlags.hasContentQuery) !== 0;
}
export function isComponent(tNode: TNode): boolean {
return (tNode.flags & TNodeFlags.isComponent) === TNodeFlags.isComponent;
}
export function isComponentDef<T>(def: DirectiveDef<T>): def is ComponentDef<T> {
return (def as ComponentDef<T>).template !== null;
}
export function isLContainer(value: RElement | RComment | LContainer | StylingContext): boolean {
// Styling contexts are also arrays, but their first index contains an element node
return Array.isArray(value) && typeof value[ACTIVE_INDEX] === 'number';
}
/**
* Retrieve the root view from any component by walking the parent `LViewData` until
* reaching the root `LViewData`.
*
* @param component any component
*/
export function getRootView(target: LViewData | {}): LViewData {
ngDevMode && assertDefined(target, 'component');
let lViewData = Array.isArray(target) ? (target as LViewData) : readPatchedLViewData(target) !;
while (lViewData && !(lViewData[FLAGS] & LViewFlags.IsRoot)) {
lViewData = lViewData[PARENT] !;
}
return lViewData;
}
export function getRootContext(viewOrComponent: LViewData | {}): RootContext {
return getRootView(viewOrComponent)[CONTEXT] as RootContext;
}
/**
* Returns the monkey-patch value data present on the target (which could be
* a component, directive or a DOM node).
*/
export function readPatchedData(target: any): LViewData|LContext|null {
return target[MONKEY_PATCH_KEY_NAME];
}
export function readPatchedLViewData(target: any): LViewData|null {
const value = readPatchedData(target);
if (value) {
return Array.isArray(value) ? value : (value as LContext).lViewData;
}
return null;
}
export function hasParentInjector(parentLocation: RelativeInjectorLocation): boolean {
return parentLocation !== NO_PARENT_INJECTOR;
}
export function getParentInjectorIndex(parentLocation: RelativeInjectorLocation): number {
return (parentLocation as any as number) & RelativeInjectorLocationFlags.InjectorIndexMask;
}
export function getParentInjectorViewOffset(parentLocation: RelativeInjectorLocation): number {
return (parentLocation as any as number) >> RelativeInjectorLocationFlags.ViewOffsetShift;
}
/**
* Unwraps a parent injector location number to find the view offset from the current injector,
* then walks up the declaration view tree until the view is found that contains the parent
* injector.
*
* @param location The location of the parent injector, which contains the view offset
* @param startView The LViewData instance from which to start walking up the view tree
* @returns The LViewData instance that contains the parent injector
*/
export function getParentInjectorView(
location: RelativeInjectorLocation, startView: LViewData): LViewData {
let viewOffset = getParentInjectorViewOffset(location);
let parentView = startView;
// For most cases, the parent injector can be found on the host node (e.g. for component
// or container), but we must keep the loop here to support the rarer case of deeply nested
// <ng-template> tags or inline views, where the parent injector might live many views
// above the child injector.
while (viewOffset > 0) {
parentView = parentView[DECLARATION_VIEW] !;
viewOffset--;
}
return parentView;
}
/**
* Unwraps a parent injector location number to find the view offset from the current injector,
* then walks up the declaration view tree until the TNode of the parent injector is found.
*
* @param location The location of the parent injector, which contains the view offset
* @param startView The LViewData instance from which to start walking up the view tree
* @param startTNode The TNode instance of the starting element
* @returns The TNode of the parent injector
*/
export function getParentInjectorTNode(
location: RelativeInjectorLocation, startView: LViewData, startTNode: TNode): TElementNode|
TContainerNode|null {
if (startTNode.parent && startTNode.parent.injectorIndex !== -1) {
// view offset is 0
const injectorIndex = startTNode.parent.injectorIndex;
let parentTNode = startTNode.parent;
while (parentTNode.parent != null && injectorIndex == parentTNode.injectorIndex) {
parentTNode = parentTNode.parent;
}
return parentTNode;
}
let viewOffset = getParentInjectorViewOffset(location);
let parentView = startView;
let parentTNode = startView[HOST_NODE] as TElementNode;
while (viewOffset > 0) {
parentView = parentView[DECLARATION_VIEW] !;
parentTNode = parentView[HOST_NODE] as TElementNode;
viewOffset--;
}
return parentTNode;
}