fix(ChangeDetector): fix issues with handling empty ranges

Author: vsavkin

modules/change_detection/src/record_range.js

@@ -100,28 +100,37 @@ export class RecordRange {
  this.headRecord = Record.createMarker(this);
  this.tailRecord = Record.createMarker(this);
 
- _glue(this.headRecord, this.tailRecord);
+ _link(this.headRecord, this.tailRecord);
  }
 
  /// addRecord assumes that the record is newly created, so it is enabled.
  addRecord(record:Record) {
  var lastRecord = this.tailRecord.prev;
 
- _glue(lastRecord, record);
- _glueEnabled(lastRecord, record);
- _glue(record, this.tailRecord);
+ _link(lastRecord, record);
+ if (!lastRecord.disabled) {
+ _linkEnabled(lastRecord, record);
+ }
+ _link(record, this.tailRecord);
  }
 
  addRange(child:RecordRange) {
  var lastRecord = this.tailRecord.prev;
- var lastEnabledRecord = this.findLastEnabledRecord();
+ var prevEnabledRecord = this._prevEnabled(this.tailRecord);
+ var nextEnabledRerord = this._nextEnabled(this.tailRecord);
+
  var firstEnabledChildRecord = child.findFirstEnabledRecord();
+ var lastEnabledChildRecord = child.findLastEnabledRecord();
+
+ _link(lastRecord, child.headRecord);
+ _link(child.tailRecord, this.tailRecord);
 
- _glue(lastRecord, child.headRecord);
- _glue(child.tailRecord, this.tailRecord);
+ if (isPresent(prevEnabledRecord) && isPresent(firstEnabledChildRecord)) {
+ _linkEnabled(prevEnabledRecord, firstEnabledChildRecord);
+ }
 
- if (isPresent(lastEnabledRecord) && isPresent(firstEnabledChildRecord)) {
- _glueEnabled(lastEnabledRecord, firstEnabledChildRecord);
+ if (isPresent(nextEnabledRerord) && isPresent(lastEnabledChildRecord)) {
+ _linkEnabled(lastEnabledChildRecord, nextEnabledRerord);
  }
  }
 
@@ -132,21 +141,14 @@ export class RecordRange {
  var next = child.tailRecord.next;
  var prev = child.headRecord.prev;
 
- _glue(prev, next);
-
- var nextEnabled = lastEnabledChildRecord.nextEnabled;
- var prevEnabled = firstEnabledChildRecord.prevEnabled;
-
- if (isPresent(nextEnabled)) nextEnabled.prevEnabled = prevEnabled;
- if (isPresent(prevEnabled)) prevEnabled.nextEnabled = nextEnabled;
- }
-
- findFirstEnabledRecord() {
- return this._nextEnabledInCurrentRange(this.headRecord);
- }
+ _link(prev, next);
 
- findLastEnabledRecord() {
- return this._prevEnabledInCurrentRange(this.tailRecord);
+ if (isPresent(firstEnabledChildRecord)) {
+ var nextEnabled = lastEnabledChildRecord.nextEnabled;
+ var prevEnabled = firstEnabledChildRecord.prevEnabled;
+ if (isPresent(nextEnabled)) nextEnabled.prevEnabled = prevEnabled;
+ if (isPresent(prevEnabled)) prevEnabled.nextEnabled = nextEnabled;
+ }
  }
 
  disableRecord(record:Record) {
@@ -162,8 +164,8 @@ export class RecordRange {
  enableRecord(record:Record) {
  if (!record.disabled) return;
 
- var prevEnabled = this._prevEnabledInCurrentRange(record);
- var nextEnabled = this._nextEnabledInCurrentRange(record);
+ var prevEnabled = this._prevEnabled(record);
+ var nextEnabled = this._nextEnabled(record);
 
  record.prevEnabled = prevEnabled;
  record.nextEnabled = nextEnabled;
@@ -188,29 +190,38 @@ export class RecordRange {
  }
 
  enableRange(child:RecordRange) {
- var prevEnabledRecord = this._prevEnabledInCurrentRange(child.headRecord);
- var nextEnabledRecord = this._nextEnabledInCurrentRange(child.tailRecord);
+ var prevEnabledRecord = this._prevEnabled(child.headRecord);
+ var nextEnabledRecord = this._nextEnabled(child.tailRecord);
 
  var firstEnabledChildRecord = child.findFirstEnabledRecord();
  var lastEnabledChildRecord = child.findLastEnabledRecord();
 
  if (isPresent(firstEnabledChildRecord) && isPresent(prevEnabledRecord)){
- _glueEnabled(prevEnabledRecord, firstEnabledChildRecord);
+ _linkEnabled(prevEnabledRecord, firstEnabledChildRecord);
  }
 
  if (isPresent(lastEnabledChildRecord) && isPresent(nextEnabledRecord)){
- _glueEnabled(lastEnabledChildRecord, nextEnabledRecord);
+ _linkEnabled(lastEnabledChildRecord, nextEnabledRecord);
  }
 
  child.disabled = false;
  }
 
- /// Returns the next enabled record in the current range. If no such record, returns null.
- _nextEnabledInCurrentRange(record:Record) {
- if (record === this.tailRecord) return null;
-
- record = record.next;
- while (isPresent(record) && record !== this.tailRecord && record.disabled) {
+ /**
+ * Returns the first enabled record in the current range.
+ *
+ * [H ER1 ER2 R3 T] returns ER1
+ * [H R1 ER2 R3 T] returns ER2
+ *
+ * If no enabled records, returns null.
+ *
+ * [H R1 R2 R3 T] returns null
+ *
+ * The function skips disabled sub ranges.
+ */
+ findFirstEnabledRecord() {
+ var record = this.headRecord.next;
+ while (record !== this.tailRecord && record.disabled) {
  if (record.isMarkerRecord && record.recordRange.disabled) {
  record = record.recordRange.tailRecord.next;
  } else {
@@ -220,19 +231,66 @@ export class RecordRange {
  return record === this.tailRecord ? null : record;
  }
 
- /// Returns the prev enabled record in the current range. If no such record, returns null.
- _prevEnabledInCurrentRange(record:Record) {
- if (record === this.headRecord) return null;
+ /**
+ * Returns the last enabled record in the current range.
+ *
+ * [H ER1 ER2 R3 T] returns ER2
+ * [H R1 ER2 R3 T] returns ER2
+ *
+ * If no enabled records, returns null.
+ *
+ * [H R1 R2 R3 T] returns null
+ *
+ * The function skips disabled sub ranges.
+ */
+ findLastEnabledRecord() {
+ var record = this.tailRecord.prev;
+ while (record !== this.headRecord && record.disabled) {
+ if (record.isMarkerRecord && record.recordRange.disabled) {
+ record = record.recordRange.headRecord.prev;
+ } else {
+ record = record.prev;
+ }
+ }
+ return record === this.headRecord ? null : record;
+ }
 
+ /**
+ * Returns the next enabled record. This search is not limited to the current range.
+ *
+ * [H ER1 T] [H ER2 T] _nextEnable(ER1) will return ER2
+ *
+ * The function skips disabled sub ranges.
+ */
+ _nextEnabled(record:Record) {
+ record = record.next;
+ while (isPresent(record) && record.disabled) {
+ if (record.isMarkerRecord && record.recordRange.disabled) {
+ record = record.recordRange.tailRecord.next;
+ } else {
+ record = record.next;
+ }
+ }
+ return record;
+ }
+
+ /**
+ * Returns the prev enabled record. This search is not limited to the current range.
+ *
+ * [H ER1 T] [H ER2 T] _nextEnable(ER2) will return ER1
+ *
+ * The function skips disabled sub ranges.
+ */
+ _prevEnabled(record:Record) {
  record = record.prev;
- while (isPresent(record) && record !== this.headRecord && record.disabled) {
+ while (isPresent(record) && record.disabled) {
  if (record.isMarkerRecord && record.recordRange.disabled) {
  record = record.recordRange.headRecord.prev;
  } else {
  record = record.prev;
  }
  }
- return record === this.headRecord ? null : record;
+ return record;
  }
 
  /**
@@ -253,12 +311,12 @@ export class RecordRange {
  }
 }
 
-function _glue(a:Record, b:Record) {
+function _link(a:Record, b:Record) {
  a.next = b;
  b.prev = a;
 }
 
-function _glueEnabled(a:Record, b:Record) {
+function _linkEnabled(a:Record, b:Record) {
  a.nextEnabled = b;
  b.prevEnabled = a;
 }