天天看點

fixture.detectChange開始單步調試,如何執行到Directive的ngAfterViewInit鈎子

/**
 * Processes a view in update mode. This includes a number of steps in a specific order:
 * - executing a template function in update mode;
 * - executing hooks;
 * - refreshing queries;
 * - setting host bindings;
 * - refreshing child (embedded and component) views.
 */
function refreshView(tView, lView, templateFn, context) {
    ngDevMode && assertEqual(isCreationMode(lView), false, 'Should be run in update mode');
    const flags = lView[FLAGS];
    if ((flags & 256 /* Destroyed */) === 256 /* Destroyed */)
        return;
    enterView(lView, lView[T_HOST]);
    const checkNoChangesMode = getCheckNoChangesMode();
    try {
        resetPreOrderHookFlags(lView);
        setBindingIndex(tView.bindingStartIndex);
        if (templateFn !== null) {
            executeTemplate(tView, lView, templateFn, 2 /* Update */, context);
        }
        const hooksInitPhaseCompleted = (flags & 3 /* InitPhaseStateMask */) === 3 /* InitPhaseCompleted */;
        // execute pre-order hooks (OnInit, OnChanges, DoCheck)
        // PERF WARNING: do NOT extract this to a separate function without running benchmarks
        if (!checkNoChangesMode) {
            if (hooksInitPhaseCompleted) {
                const preOrderCheckHooks = tView.preOrderCheckHooks;
                if (preOrderCheckHooks !== null) {
                    executeCheckHooks(lView, preOrderCheckHooks, null);
                }
            }
            else {
                const preOrderHooks = tView.preOrderHooks;
                if (preOrderHooks !== null) {
                    executeInitAndCheckHooks(lView, preOrderHooks, 0 /* OnInitHooksToBeRun */, null);
                }
                incrementInitPhaseFlags(lView, 0 /* OnInitHooksToBeRun */);
            }
        }
        // First mark transplanted views that are declared in this lView as needing a refresh at their
        // insertion points. This is needed to avoid the situation where the template is defined in this
        // `LView` but its declaration appears after the insertion component.
        markTransplantedViewsForRefresh(lView);
        refreshEmbeddedViews(lView);
        // Content query results must be refreshed before content hooks are called.
        if (tView.contentQueries !== null) {
            refreshContentQueries(tView, lView);
        }
        // execute content hooks (AfterContentInit, AfterContentChecked)
        // PERF WARNING: do NOT extract this to a separate function without running benchmarks
        if (!checkNoChangesMode) {
            if (hooksInitPhaseCompleted) {
                const contentCheckHooks = tView.contentCheckHooks;
                if (contentCheckHooks !== null) {
                    executeCheckHooks(lView, contentCheckHooks);
                }
            }
            else {
                const contentHooks = tView.contentHooks;
                if (contentHooks !== null) {
                    executeInitAndCheckHooks(lView, contentHooks, 1 /* AfterContentInitHooksToBeRun */);
                }
                incrementInitPhaseFlags(lView, 1 /* AfterContentInitHooksToBeRun */);
            }
        }
        setHostBindingsByExecutingExpandoInstructions(tView, lView);
        // Refresh child component views.
        const components = tView.components;
        if (components !== null) {
            refreshChildComponents(lView, components);
        }
        // View queries must execute after refreshing child components because a template in this view
        // could be inserted in a child component. If the view query executes before child component
        // refresh, the template might not yet be inserted.
        const viewQuery = tView.viewQuery;
        if (viewQuery !== null) {
            executeViewQueryFn(2 /* Update */, viewQuery, context);
        }
        // execute view hooks (AfterViewInit, AfterViewChecked)
        // PERF WARNING: do NOT extract this to a separate function without running benchmarks
        if (!checkNoChangesMode) {
            if (hooksInitPhaseCompleted) {
                const viewCheckHooks = tView.viewCheckHooks;
                if (viewCheckHooks !== null) {
                    executeCheckHooks(lView, viewCheckHooks);
                }
            }
            else {
                const viewHooks = tView.viewHooks;
                if (viewHooks !== null) {
                    executeInitAndCheckHooks(lView, viewHooks, 2 /* AfterViewInitHooksToBeRun */);
                }
                incrementInitPhaseFlags(lView, 2 /* AfterViewInitHooksToBeRun */);
            }
        }
        if (tView.firstUpdatePass === true) {
            // We need to make sure that we only flip the flag on successful `refreshView` only
            // Don't do this in `finally` block.
            // If we did this in `finally` block then an exception could block the execution of styling
            // instructions which in turn would be unable to insert themselves into the styling linked
            // list. The result of this would be that if the exception would not be throw on subsequent CD
            // the styling would be unable to process it data and reflect to the DOM.
            tView.firstUpdatePass = false;
        }
        // Do not reset the dirty state when running in check no changes mode. We don't want components
        // to behave differently depending on whether check no changes is enabled or not. For example:
        // Marking an OnPush component as dirty from within the `ngAfterViewInit` hook in order to
        // refresh a `NgClass` binding should work. If we would reset the dirty state in the check
        // no changes cycle, the component would be not be dirty for the next update pass. This would
        // be different in production mode where the component dirty state is not reset.
        if (!checkNoChangesMode) {
            lView[FLAGS] &= ~(64 /* Dirty */ | 8 /* FirstLViewPass */);
        }
        if (lView[FLAGS] & 1024 /* RefreshTransplantedView */) {
            lView[FLAGS] &= ~1024 /* RefreshTransplantedView */;
            updateTransplantedViewCount(lView[PARENT], -1);
        }
    }
    finally {
        leaveView();
    }
}
      

從refreshView函數調用hook的順序來看,ngOnChanges hook的執行一定先于ngAfterViewInit:

fixture.detectChange開始單步調試,如何執行到Directive的ngAfterViewInit鈎子

繼續閱讀