function Observer(data) {
this.data = data;
this.walk(data);
}
Observer.prototype = {
constructor: Observer,
walk: function(data) {
var me = this;
Object.keys(data).forEach(function(key) {
me.convert(key, data[key]);
});
},
convert: function(key, val) {
this.defineReactive(this.data, key, val);
},
defineReactive: function(data, key, val) {
var dep = new Dep();
var childObj = observe(val);
Object.defineProperty(data, key, {
enumerable: true./ / can be enumerated
configurable: false.// cannot define again
get: function() {
if (Dep.target) {
dep.depend();
}
return val;
},
set: function(newVal) {
if (newVal === val) {
return;
}
val = newVal;
// Listen if the new value is object
childObj = observe(newVal);
// Notify subscribersdep.notify(); }}); }};function observe(value, vm) {
if(! value ||typeofvalue ! = ='object') {
return;
}
return new Observer(value);
};
Copy the codevar uid = 0;
function Dep() {
this.id = uid++;
this.subs = [];
}
Dep.prototype = {
addSub: function(sub) {
this.subs.push(sub);
},
depend: function() {
Dep.target.addDep(this);
},
removeSub: function(sub) {
var index = this.subs.indexOf(sub);
if(index ! = -1) {
this.subs.splice(index, 1); }},notify: function() {
this.subs.forEach(function(sub) { sub.update(); }); }}; Dep.target =null;
Copy the codefunction Compile(el, vm) {
this.$vm = vm;
this.$el = this.isElementNode(el) ? el : document.querySelector(el);
if (this.$el) {
this.$fragment = this.node2Fragment(this.$el);
this.init();
this.$el.appendChild(this.$fragment);
}
}
Compile.prototype = {
constructor: Compile,
node2Fragment: function(el) {
var fragment = document.createDocumentFragment(),
child;
// Copy the native node to the fragment
while (child = el.firstChild) {
fragment.appendChild(child);
}
return fragment;
},
init: function() {
this.compileElement(this.$fragment);
},
compileElement: function(el) {
var childNodes = el.childNodes,
me = this;
[].slice.call(childNodes).forEach(function(node) {
var text = node.textContent;
var reg = / \ {\ {(. *) \} \} /;
if (me.isElementNode(node)) {
me.compile(node);
} else if (me.isTextNode(node) && reg.test(text)) {
me.compileText(node, RegExp.$1.trim());
}
if(node.childNodes && node.childNodes.length) { me.compileElement(node); }}); },compile: function(node) {
var nodeAttrs = node.attributes,
me = this;
[].slice.call(nodeAttrs).forEach(function(attr) {
var attrName = attr.name;
if (me.isDirective(attrName)) {
var exp = attr.value;
var dir = attrName.substring(2);
// Event command
if (me.isEventDirective(dir)) {
compileUtil.eventHandler(node, me.$vm, exp, dir);
// Common instruction
} else{ compileUtil[dir] && compileUtil[dir](node, me.$vm, exp); } node.removeAttribute(attrName); }}); },compileText: function(node, exp) {
compileUtil.text(node, this.$vm, exp);
},
isDirective: function(attr) {
return attr.indexOf('v-') = =0;
},
isEventDirective: function(dir) {
return dir.indexOf('on') = = =0;
},
isElementNode: function(node) {
return node.nodeType == 1;
},
isTextNode: function(node) {
return node.nodeType == 3; }};// Instruction processing set
var compileUtil = {
text: function(node, vm, exp) {
this.bind(node, vm, exp, 'text');
},
html: function(node, vm, exp) {
this.bind(node, vm, exp, 'html');
},
model: function(node, vm, exp) {
this.bind(node, vm, exp, 'model');
var me = this,
val = this._getVMVal(vm, exp);
node.addEventListener('input'.function(e) {
var newValue = e.target.value;
if (val === newValue) {
return;
}
me._setVMVal(vm, exp, newValue);
val = newValue;
});
},
class: function(node, vm, exp) {
this.bind(node, vm, exp, 'class');
},
bind: function(node, vm, exp, dir) {
var updaterFn = updater[dir + 'Updater'];
updaterFn && updaterFn(node, this._getVMVal(vm, exp));
new Watcher(vm, exp, function(value, oldValue) {
updaterFn && updaterFn(node, value, oldValue);
});
},
// Event processing
eventHandler: function(node, vm, exp, dir) {
var eventType = dir.split(':') [1],
fn = vm.$options.methods && vm.$options.methods[exp];
if (eventType && fn) {
node.addEventListener(eventType, fn.bind(vm), false); }},_getVMVal: function(vm, exp) {
var val = vm;
exp = exp.split('. ');
exp.forEach(function(k) {
val = val[k];
});
return val;
},
_setVMVal: function(vm, exp, value) {
var val = vm;
exp = exp.split('. ');
exp.forEach(function(k, i) {
// Not the last key, update the value of val
if (i < exp.length - 1) {
val = val[k];
} else{ val[k] = value; }}); }};var updater = {
textUpdater: function(node, value) {
node.textContent = typeof value == 'undefined' ? ' ' : value;
},
htmlUpdater: function(node, value) {
node.innerHTML = typeof value == 'undefined' ? ' ' : value;
},
classUpdater: function(node, value, oldValue) {
var className = node.className;
className = className.replace(oldValue, ' ').replace(/\s$/.' ');
var space = className && String(value) ? ' ' : ' ';
node.className = className + space + value;
},
modelUpdater: function(node, value, oldValue) {
node.value = typeof value == 'undefined' ? ' ': value; }};Copy the codefunction Watcher(vm, expOrFn, cb) {
this.cb = cb;
this.vm = vm;
this.expOrFn = expOrFn;
this.depIds = {};
if (typeof expOrFn === 'function') {
this.getter = expOrFn;
} else {
this.getter = this.parseGetter(expOrFn.trim());
}
this.value = this.get();
}
Watcher.prototype = {
constructor: Watcher,
update: function() {
this.run();
},
run: function() {
var value = this.get();
var oldVal = this.value;
if(value ! == oldVal) {this.value = value;
this.cb.call(this.vm, value, oldVal); }},addDep: function(dep) {
// 1. Every time run() is called, the getter for the corresponding property is fired
// The getter will fire dep.depend(), which will fire addDep here
// 2. If the depIds of the corresponding attribute are already in the depIds of the current watcher, it is not a new attribute, but has changed its value
// There is no need to add the current watcher to the deP of the property
// 3. If the property is a new property, add the current watcher to the deP of the new property
// If the value of child.name is changed by vm.child = {name: 'a'}, child.name is a new attribute
// Add the current watcher(child.name) to the dep of the new child.name
// If watcher is not added to the dep of the new child.name, the setter and dep are invalid
// The watcher will not receive notification when the child. Name = XXX is assigned
// 4. The watcher of each child is added to the deP of the child as well as the parent
// The watcher of the child property is notified to update the parent property when the parent property changes
// this is done in this.get() --> this.getVmVal (). ForEach will evaluate from the parent, indirectly calling its getter
// addDep() is triggered, and the current wacher is added to the deP of each parent procedure attribute throughout the forEach process
// For example, if the current watcher is 'child.child.name', then the deP of child, child.child, and child.child.name will be added to the current watcher
if (!this.depIds.hasOwnProperty(dep.id)) {
dep.addSub(this);
this.depIds[dep.id] = dep; }},get: function() {
Dep.target = this;
var value = this.getter.call(this.vm, this.vm);
Dep.target = null;
return value;
},
parseGetter: function(exp) {
if (/[^\w.$]/.test(exp)) return;
var exps = exp.split('. ');
return function(obj) {
for (var i = 0, len = exps.length; i < len; i++) {
if(! obj)return;
obj = obj[exps[i]];
}
returnobj; }}};Copy the codefunction MVVM(options) {
this.$options = options || {};
var data = this._data = this.$options.data;
var me = this;
// Data broker
// implement vm.xxx -> vm._data.xxx
Object.keys(data).forEach(function(key) {
me._proxyData(key);
});
this._initComputed();
observe(data, this);
this.$compile = new Compile(options.el || document.body, this)
}
MVVM.prototype = {
constructor: MVVM,
$watch: function(key, cb, options) {
new Watcher(this, key, cb);
},
_proxyData: function(key, setter, getter) {
var me = this;
setter = setter ||
Object.defineProperty(me, key, {
configurable: false.enumerable: true.get: function proxyGetter() {
return me._data[key];
},
set: function proxySetter(newVal) { me._data[key] = newVal; }}); },_initComputed: function() {
var me = this;
var computed = this.$options.computed;
if (typeof computed === 'object') {
Object.keys(computed).forEach(function(key) {
Object.defineProperty(me, key, {
get: typeof computed[key] === 'function'
? computed[key]
: computed[key].get,
set: function() {}}); }); }}};Copy the code