build_your_own_angularjs_sample

Build Your Own Angular Chapter 1. Scopes And Digest
Scope.prototype.$digest = function() {
var ttl = 10;
var dirty;
this.$$lastDirtyWatch = null;
this.$beginPhase("$digest");
do {
while (this.$$asyncQueue.length) {
var asyncTask = this.$$asyncQueue.shift();
asyncTask.scope.$eval(asyncTask.expression);
}
dirty = this.$$digestOnce();
if ((dirty || this.$$asyncQueue.length) && !(ttl--)) {
this.$clearPhase();
throw "10 digest iterations reached";
}
} while (dirty || this.$$asyncQueue.length);
this.$clearPhase();
};
Let’s also tweak $apply so that it also sets the phase for itself:
src/scope.js
Scope.prototype.$apply = function(expr) {
try {
this.$beginPhase("$apply");
return this.$eval(expr);
} finally {
this.$clearPhase();
this.$digest();
}
};
And finally we can add the scheduling of the $digest into $evalAsync. Let’s first define
the requirement as a unit test:
test/scope_spec.js
it("schedules a digest in $evalAsync", function(done) {
scope.aValue = "abc";
scope.counter = 0;
scope.$watch(
function(scope) { return scope.aValue; },
function(newValue, oldValue, scope) {
scope.counter++;
}
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