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用原生js简单模仿angular的依赖注入

2017-05-08 23:00 441 查看
大家都知道angular 依赖注入很神奇,跟我们平常写代码的风格思维差别很大,不过仔细分析确是一个很有意思的东西,依赖注入早期也叫依赖倒置,是java中有的。废话不多少直接上例子 本帖属于原创,转载请出名出处。


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>无标题文档</title>
</head>
<body ng-app="myApp">
<div ng-controller="firstController">
</div>
<script>
var angular = {
injectionName: {
$scope: {
$$ChildScope: null,
$$childHead: null,
$$childTail: null,
$$listenerCount: 'Object',
$$listeners: 'Object',
$$nextSibling: null,
$$prevSibling: null,
$$watchers: null,
$$watchersCount: 0,
$id: 2,
$parent: 'Scope',
},
$injector: {
annotate: function (fn, strictDi, name) {
},
get: function (serviceName, caller) {
},
has: function (name) {
},
instantiate: function (Type, locals, serviceName) {
},
invoke: function (fn, self, locals, serviceName) {
},
modules: 'Object',
strictDi: false,
},
$rootScope: {
$$ChildScope: function(){},
$$applyAsyncQueue: Array[0],
$$asyncQueue: Array[0],
$$childHead: 'ChildScope',
$$childTail: 'ChildScope',
$$destroyed: false,
$$isolateBindings: null,
$$listenerCount: 'Object',
$$listeners: 'Object',
$$nextSibling: null,
$$phase: null,
$$postDigestQueue: Array[0],
$$prevSibling: null,
$$watchers: null,
$$watchersCount: 0,
$id: 1,
$parent: null,
$root: 'Scope'
},
$http: function(requestConfig) {

if (!isObject(requestConfig)) {
throw minErr('$http')('badreq', 'Http request configuration must be an object.  Received: {0}', requestConfig);
}

if (!isString($sce.valueOf(requestConfig.url))) {
throw minErr('$http')('badreq', 'Http request configuration url must be a string or a $sce trusted object.  Received: {0}', requestConfig.url);
}

var config = extend({
method: 'get',
transformRequest: defaults.transformRequest,
transformResponse: defaults.transformResponse,
paramSerializer: defaults.paramSerializer,
jsonpCallbackParam: defaults.jsonpCallbackParam
}, requestConfig);

config.headers = mergeHeaders(requestConfig);
config.method = uppercase(config.method);
config.paramSerializer = isString(config.paramSerializer) ?
$injector.get(config.paramSerializer) : config.paramSerializer;

$browser.$$incOutstandingRequestCount();

var requestInterceptors = [];
var responseInterceptors = [];
var promise = $q.resolve(config);

// apply interceptors
forEach(reversedInterceptors, function(interceptor) {
if (interceptor.request || interceptor.requestError) {
requestInterceptors.unshift(interceptor.request, interceptor.requestError);
}
if (interceptor.response || interceptor.responseError) {
responseInterceptors.push(interceptor.response, interceptor.responseError);
}
});

promise = chainInterceptors(promise, requestInterceptors);
promise = promise.then(serverRequest);
promise = chainInterceptors(promise, responseInterceptors);
promise = promise.finally(completeOutstandingRequest);

return promise;

function chainInterceptors(promise, interceptors) {
for (var i = 0, ii = interceptors.length; i < ii;) {
var thenFn = interceptors[i++];
var rejectFn = interceptors[i++];

promise = promise.then(thenFn, rejectFn);
}

interceptors.length = 0;

return promise;
}

function completeOutstandingRequest() {
$browser.$$completeOutstandingRequest(noop);
}

function executeHeaderFns(headers, config) {
var headerContent, processedHeaders = {};

forEach(headers, function(headerFn, header) {
if (isFunction(headerFn)) {
headerContent = headerFn(config);
if (headerContent != null) {
processedHeaders[header] = headerContent;
}
} else {
processedHeaders[header] = headerFn;
}
});

return processedHeaders;
}

function mergeHeaders(config) {
var defHeaders = defaults.headers,
reqHeaders = extend({}, config.headers),
defHeaderName, lowercaseDefHeaderName, reqHeaderName;

defHeaders = extend({}, defHeaders.common, defHeaders[lowercase(config.method)]);

// using for-in instead of forEach to avoid unnecessary iteration after header has been found
defaultHeadersIteration:
for (defHeaderName in defHeaders) {
lowercaseDefHeaderName = lowercase(defHeaderName);

for (reqHeaderName in reqHeaders) {
if (lowercase(reqHeaderName) === lowercaseDefHeaderName) {
continue defaultHeadersIteration;
}
}

reqHeaders[defHeaderName] = defHeaders[defHeaderName];
}

// execute if header value is a function for merged headers
return executeHeaderFns(reqHeaders, shallowCopy(config));
}

function serverRequest(config) {
var headers = config.headers;
var reqData = transformData(config.data, headersGetter(headers), undefined, config.transformRequest);

// strip content-type if data is undefined
if (isUndefined(reqData)) {
forEach(headers, function(value, header) {
if (lowercase(header) === 'content-type') {
delete headers[header];
}
});
}

if (isUndefined(config.withCredentials) && !isUndefined(defaults.withCredentials)) {
config.withCredentials = defaults.withCredentials;
}

// send request
return sendReq(config, reqData).then(transformResponse, transformResponse);
}

function transformResponse(response) {
// make a copy since the response must be cacheable
var resp = extend({}, response);
resp.data = transformData(response.data, response.headers, response.status,
config.transformResponse);
return (isSuccess(response.status))
? resp
: $q.reject(resp);
}
},
$q:function(resolver) {
if (!isFunction(resolver)) {
throw $qMinErr('norslvr', 'Expected resolverFn, got \'{0}\'', resolver);
}

var promise = new Promise();

function resolveFn(value) {
resolvePromise(promise, value);
}

function rejectFn(reason) {
rejectPromise(promise, reason);
}

resolver(resolveFn, rejectFn);

return promise;
},
$log: console.log,
$window: window,
$timeout: setTimeout,
$interval: setInterval,
$location: window.location
},
getEle: function (ele, ele2) {
if (arguments.length == 1) {
return document.getElementsByTagName(ele);
} else {
return ele.getElementsByTagName(ele2);
}

},
module: function (module_str) {
var ele_arr = this.getEle("*"),
flag = false;
app_ele = null;
for (var i = 0; i < ele_arr.length; i++) {
if (ele_arr[i].getAttribute('ng-app') != null) {
flag = true;
app_ele = ele_arr[i];
break;
}

}

if (app_ele.getAttribute('ng-app') != module_str) {
throw new Error("angular ng-app  " + module_str + " not registered ");
}
if (!flag) {
throw new Error("angular   ng-app not registered   ");
}
this.tool.appEle = app_ele;
return this.tool;

},
tool: {
controller: function (controller_str, functionName) {
var ele_arr = angular.getEle(this.appEle, "*"),
flag = false;
app_ele = null;
for (var i = 0; i < ele_arr.length; i++) {
if (ele_arr[i].getAttribute('ng-controller') != null) {
flag = true;
app_ele = ele_arr[i];
break;
}

}

if (app_ele.getAttribute('ng-controller') != controller_str) {
throw new Error("angular ng-controller  " + controller_str + " not registered ");
}
if (!flag) {
throw new Error("angular   ng-controller not registered   ");
}

var pattern = new RegExp("\\((.| )+?\\)", "igm");
var str = functionName.toString().match(pattern)
str = str[0].replace(/\s/g, "");
str = str.substring(1, str.toString().length - 1);
var arr = str.split(',');
var args = [];
for (var i = 0; i < arr.length; i++) {
args[i] = angular.injectionName[arr[i]]
}
functionName.apply(null, args);

}

}
}
angular.module('myApp')
.controller('firstController', function ($scope,$injector) {

console.log($scope);
console.log($injector)
});

</script>
</body>
</html>



                                            
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