我是jQuery的绝对优势。我为我的应用程序编写了一些代码并将其放入.js文件中：
我应该如何避免jQuery中的代码重复？我应该在哪里存储我的.js代码（一个巨大的.js文件，几个较小或直接的html源代码）？
这是我的.js文件：
$(document).ready(function() {
$("label[for='id_category1'], #id_category1, label[for='id_subcategory1'],#id_subcategory1 ").hide();
$('select[name=subcategory]').empty();
$('select[name=subcategory]').prepend('<option value="Not selected" selected disabled>Select Category...</option>');
$('select[name=subcategory1]').empty();
$('select[name=subcategory1]').prepend('<option value="Not selected" selected disabled>Select Category...</option>');
// called when category field changes from initial value
$('#id_group').change(function() {
var $this = $(this);
if ($this.find('option:selected').attr('value') == 'premium') {
$("label[for='id_category1'], #id_category1").show();
$("label[for='id_subcategory1'], #id_subcategory1").show();
} else {
$("label[for='id_category1'], #id_category1").hide();
$("label[for='id_subcategory1'], #id_subcategory1").hide();
}
})
$('#id_category').change(function() {
var $this = $(this);
if ($this.find('option:selected').index() !== 0) {
category_id = $('select[name=category]').val();
request_url = '/get_subcategory/' + category_id + '/';
$.ajax({
url: request_url,
type: "GET",
success: function(data) {
$('select[name=subcategory]').empty();
$.each(data, function(key, value) {
$('select[name=subcategory]').append('<option value="' + key + '">' + value + '</option>');
});
}
})
}
})
$('#id_category1').change(function() {
var $this = $(this);
if ($this.find('option:selected').index() !== 0) {
category_id = $('select[name=category1]').val();
request_url = '/get_subcategory/' + category_id + '/';
$.ajax({
url: request_url,
type: "GET",
success: function(data) {
$('select[name=subcategory1]').empty();
$.each(data, function(key, value) {
$('select[name=subcategory1]').append('<option value="' + key + '">' + value + '</option>');
});
}
})
}
})
$("label[for='id_keywords']").html("Keywords 0/100");
$('#id_keywords').keyup(function() {
var charsno = $(this).val().length;
$("label[for='id_keywords']").html("Keywords (" + charsno + "/100)");
});
$("label[for='id_description']").html("Description 0/250");
$('#id_description').keyup(function() {
var charsno = $(this).val().length;
$("label[for='id_description']").html("Description (" + charsno + "/2500)");
});
});
感谢您提供有关初学者的任何线索。
答案 0 :(得分：0)
始终将JavaScript与HTML分开。
始终根据单独的功能分离并加载单独的javascript文件。
然后尝试分解为MVC类型的架构。我一直在那里javascript文件长达2000行 - 它无法管理编辑和调试。
总是尝试使用类。
类架构在Javascript中是伪的，但是：
var view;
var model;
var ctrl;
/** - js_include_mvc.js
* as per:
* http://stackoverflow.com/questions/15192722/javascript-extending-class
* provides the bare minimum facility to instantiate MVC objects if the base mvc classes are not subclassed
* this ensures there is always js mvc
*
*/
Ctrl.inherits(BaseCtrl);
function Ctrl(args) {
BaseCtrl.apply(this, arguments);
Ctrl.prototype.boot = function () {
}
}
View.inherits(BaseView);
function View(args) {
BaseView.apply(this, arguments);
View.prototype.boot = function () {
}
}
Model.inherits(BaseModel);
function Model(args) {
BaseModel.apply(this, arguments);
Model.prototype.boot = function () {
}
}
然后例如：
function BaseView() {
BaseView.prototype.somemethod = function () {
//some functionality here
return "I am a View";
}
}
最后在全局页面脚本中调用它：
var view=new BaseView();
view.somemethod();
输出：
“我是一个观点”
我将类定义为BaseView，因为我放置了总是在这里重用的代码，但是BaseView类可以根据应用程序进一步扩展。因此，BaseView被用作我所有应用程序的主存储库，并根据需要对其进行扩展。
答案 1 :(得分：0)
我的一些代码注释需要重写，但我的Ajax类是这样的：
if (SERVER_INTERFACES == undefined) {
var SERVER_INTERFACES = {};//global server array required for named multiple servers and asynch data callbacks
}
/** Ajax_js - communicates with the server to retreive data
*
* @param String newName is the name this class can reference for things like callbacks
* @param Strin newUrl
* @param String newNamedServer is the resource url defined as a php ajax server class
* @returns {Ajax}
*/
function Ajax_m(newName, newUrl, newNamedServer) {
this.namedServer = newNamedServer;
this.interface_name = newName;
this.url = newUrl;
this.server_data; //allows a query to be given an id and the result data stored and accessible without having to manipulate into method arguments which might require data changes
this.server_data = new Array(); //allows a query to be given an id and the result data stored and accessible without having to manipulate into method arguments which might require data changes
this.request_index = 0;
this.multiqueryindex = 0;
this.multiqueryctrl = new Array();
this.dataType = "json";
this.reqType = "post";
SERVER_INTERFACES[this.interface_name] = this;
Ajax_m.prototype.request = function (requestobj, callback, optargs) {
optargs = model.array_defaults(optargs, {runtagvals: {}});
if (optargs.id == undefined) {
this.request_index++;
} else {
this.request_index = optargs.id;
}
var request_id = this.request_index;
if (typeof requestobj == "string") {
//legacy was the requestobj as a string which is set to request and defaults assumed
//attempt to parse ajaxRequestSubType as first 'word'
var clauseend = requestobj.indexOf(" ");
var ajaxRequestSubType = requestobj.substr(0, clauseend);
requestobj = {ajaxRequestSubType: ajaxRequestSubType, request: requestobj, callback: callback, request_id: request_id};
} else {
//for legacy if callback and id are defined they are added but if in requestobj they will be overridden
var args = {callback: callback, request_id: request_id};
for (var r in requestobj) {
args[r] = requestobj[r];
}
requestobj = args;
}
//ensure default settings
var requestbuild = model.array_defaults(
requestobj,
{
request: null,
callback: "",
errorCallback: null,
request_id: null,
interface_name: this.interface_name,
responsedata: null,
multirequestid: null,
ajaxRequestSubType: "",
ajaxRequestType: "database", //default to use database cfg definitions of site
ismultiparent: false,
_method: "PATCH"//for laravel5
}
);
requestbuild.request = model.runtagreplace(requestbuild.request, optargs.runtagvals);
this.server_data[request_id] = requestbuild;
//debug in chrome as firebug fucks up badly with switch control
switch (requestbuild.ajaxRequestSubType) {
//control processes so no actual ajax requests are required
case "multirequest_parent":
case "multilrequest_submit":
break;
default:
this.server_data[request_id].ajax = $.ajax({
headers: {
'X-CSRF-TOKEN': laravelCSRF//this is a constant from php JSCONSTANTS
},
url: this.url,
type: this.reqType,
data: requestbuild,
dataType: this.dataType,
success: function (server_response) {
var requestobj = SERVER_INTERFACES[server_response.interface_name]; //.server_data[request_id];
if (requestobj.server_data[request_id] != undefined) {//check existence - a reset might have been requested since query sent
requestobj.setRequestResult(server_response.request_id, server_response.data);
//check through request types to eventual detect a simple callback from client object
switch (server_response.ajaxRequestSubType) {
case "select":
case "call":
if (server_response.flag_multiRequestChild) {
var parentinterface_name = requestobj.interface_name;
var parentinterface_id = server_response.multirequest_parent;
var multiobj =
SERVER_INTERFACES[parentinterface_name].
server_data[parentinterface_id];
multiobj.request_returned++;
if (multiobj.request_returned == multiobj.request_total) {
requestobj.multiRequestFinish(requestobj.server_data[request_id].multirequest_parent);
}
} else if (server_response.callback != "") {
eval(server_response.callback + "(" + server_response.request_id + ",'" + requestobj.interface_name + "')");
}
break;
case "submit":
if (!server_response.ismultipart) {
if (server_response.callback != "") {
eval(server_response.callback + "(" + server_response.request_id + ")");
}
} else {
var multiobj = SERVER_INTERFACES[server_response.interface_name].server_data[requestobj.server_data[request_id].multisubmit_parent];
multiobj.submit_returned++;
if (multiobj.submit_returned == multiobj.submit_total) {
requestobj.multiSubmitFinish(requestobj.server_data[request_id].multisubmit_parent);
}
}
break;
case "jscsv":
var downloadobj = SERVER_INTERFACES[server_response.interface_name].server_data[request_id];
requestobj.downloadrun(downloadobj);
break;
default://need failover as cannot determine what to do
break;
}
} else {
var faildata = "error";
}
},
error: function (server_response) {
//parse unhelpful error 'data' to relocate correct ajax request object
var errordata = this.data.split("&");
var intefacename;
var requestid;
var errorobj = {isajaxerror: true};
for (var i in errordata) {
var keyval = errordata[i].split("=");
errorobj[keyval[0]] = keyval[1];
if (errordata[i].indexOf("request_id=") != -1) {
requestid = errordata[i].substr(errordata[i].indexOf("=") + 1);
}
if (errordata[i].indexOf("interface_name=") != -1) {
interfacename = errordata[i].substr(errordata[i].indexOf("=") + 1);
}
}
var parentobj = SERVER_INTERFACES[interfacename];
var requestobj = parentobj.server_data[requestid];
//new object required as out of scope
errorobj["responseText"] = server_response.responseText;
parentobj.setRequestResult(errorobj["request_id"], errorobj);
eval(errorobj["callback"] + "(" + errorobj["request_id"] + ")");
}
});
break;
}
return request_id;
}
/*
* handles ajax where data is not expected back such as an insert statement or email send
* but can expect a response message such as 'ok' or an error message
*/
Ajax_m.prototype.submit = function (type, submitdata, callback) {
this.request({ajaxRequestSubType: "submit", type: type, submitdata: submitdata, ismultipart: false, callback: callback});
}
/*
* 'multiSubmit' handles ajax where data is not expected back such as an insert statement or email send
* but can expect a response message such as 'ok' or an error message
* EXAMPLE
var multisub = [
{
type: "update",
data: {
table: "[xondbs1].stats.dbo.a_ppuser",
values: {'email': 'tim'},
matchfield: 'keyval', matchvalue: 'Q00010017'
}
},
{
type: "update",
data: {
table: "[xondbs1].stats.dbo.a_ppuser",
values: {'email': 'tim'},
matchfield: 'keyval', matchvalue: 'Q00010017'
}
}
];
ajaxdbobj.multiSubmit(multisub, "callbackfunctionname");
*/
Ajax_m.prototype.multiSubmit = function (submitobject, callback) {
var parent_request_id = this.request({ajaxRequestSubType: "multisubmit_parent", submit_total: count(submitobject), submit_returned: 0, id_list: [], submit: {}, response: {}, callback: callback});
for (var s in submitobject) {
var child_request_id = this.request({
ajaxRequestSubType: "submit",
multisubmit_parent: parent_request_id,
ismultipart: true,
type: submitobject[s].type,
submitdata: submitobject[s].data
});
this.server_data[parent_request_id].id_list[child_request_id] = s;
}
return parent_request_id;
}
/*
* sets up mutli queries to only run callback when all complete
* the requestobject is key=>query assoc to which results are assign the same key
* when all results complete the callback is run giving the request_id in the normal way
* to return the multi result object
*/
Ajax_m.prototype.multiRequest = function (requestobject, callback) {
var parent_request_id = this.request({ajaxRequestSubType: "multirequest_parent", request_total: count(requestobject), request_returned: 0, id_list: [], request: {}, data: {}, callback: callback});
for (var r in requestobject) {
/*var child_request = {
request: requestobject[r],
ajaxRequestSubType: "multirequest_child",
}*/
var child_request = requestobject[r];
child_request.multirequest_parent = parent_request_id;
child_request.flag_multiRequestChild = true;
var child_request_id = this.request(child_request);
this.server_data[parent_request_id].id_list[child_request_id] = r;
}
return parent_request_id;
}
/*
* sets up facility for javascript to download data locally
* there is no callback facility required as this is a one-way request
* with a url returned pointing to the resultant file, this is ultimately sent as a new
* window request to the file which will be handled on the native machine settings
*
* for integrity and security the server sets a unique filename ending
*
* First a meta query is sent to process what action to take - eg inform that data is emailed when ready if a length query
* This is then fed back to the user as to what is happening before the actual query can begin.
* @param type determines what download process should be used
* @param dataArgs determines how the data is retrieived
*/
Ajax_m.prototype.requestDownload = function (fileprefix, type, downloadData) {
view.dialogOpen({
title: "Download",
dialogbody: "preparing download . . .",
closeButton: false//change to false after test
});
this.request({ajaxRequestType: "requestDownload", fileprefix: fileprefix, ajaxRequestSubType: type, downloadData: downloadData});
//this.server_data[downloadid].callbacktype = action;
}
/*
* opens url to processed data downloadRequest in a new window / tab
*/
Ajax_m.prototype.downloadrun = function (reqobj) {
//getRequestResult
var meta = this.getRequestResult(reqobj.request_id);
switch (reqobj.ajaxRequestSubType) {
case "jscsv":
view.dialogOpen({
title: "Download",
dialogbody: "Your file download has finished processing.<br />Please ensure you have popups enabled for this site to be able to access the file.",
closeOK: true
});
window.open(meta.downloadurl, "download");
break;
case "dbcsv":
view.dialogOpen({
title: "Download",
dialogbody: meta.msg,
closeOK: true
});
this.request({ajaxRequestSubType: "downloadrun", filename: reqobj.filename, type: reqobj.type, downloadsource: reqobj.downloadsource}, '');
break;
}
}
/*
* kills data (returning requested will be ignored)
*/
Ajax_m.prototype.reset = function () {
for (var s in this.server_data) {
if (this.server_data[s].ajax) {
this.server_data[s].ajax.abort();
}
}
this.server_data = new Array();
this.request_index = 0;
}
/*
* relates misc data to query eg
*/
Ajax_m.prototype.setMisc = function (request_id, miscobject) {
this.server_data[request_id].misc = miscobject;
}
/*
* gets misc data to query eg
*/
Ajax_m.prototype.getMisc = function (request_id) {
return this.server_data[request_id].misc;
}
/*
* get orig query sent
*/
Ajax_m.prototype.setAjaxRequestType = function (type) {
this.reqType = type;
}
/*
* get orig query sent
*/
Ajax_m.prototype.setDataType = function (type) {
this.dataType = type;
}
/*
* get orig query sent
*/
Ajax_m.prototype.getRequest = function (request_id) {
return this.server_data[request_id].request;
}
/*
* return result data for given request id
*/
Ajax_m.prototype.getRequestResult = function (id) {
var data;//leave as undefined so code fails in the client
if (this.server_data[id]) {
data = this.server_data[id].data;
}
return data;
//return data;
}
/*
* return result data for given request id indexed by a field name
* if its not unique there will be data loss and a 'distinct' set will be returned
*/
Ajax_m.prototype.getRequestResultByCol = function (id, colname) {
var reqdata = this.getRequestResult(id);
var data = {};
for (var r in reqdata) {
data.r[colname] = data.r;
delete data.r[colname][colname];
}
return data;
//return data;
}
/**
* return a single value for given request id, if request id did actual generate
* multiple values then only the first is returned
* if this was a multirequest, the named key of the multi request is required
*/
Ajax_m.prototype.getRequestValue = function (id, multi_id) {
var retval;
if (!this.server_data[id].ismultiparent) {
retval = this.server_data[id].data[0];
} else {
retval = this.server_data[id].data[multi_id][0];
}
if (retval == undefined) {
retval = null;
}
return retval;
}
/*
* removes a query and data from memory
*/
Ajax_m.prototype.deleteRequest = function (request_id) {
delete this.server_data[request_id];
}
Ajax_m.prototype.error = function (serverData, st, ert) {
//all errors should have been handled, but just in case
var errorReport = "error";
errorReport += st;
alert("error");
}
/**********************************************************************************************************
INTENDED AS PRIVATE FUNCTIONS
**********************************************************************************************************/
/*
* sets result data for this instance for given query id - eliminates the need for eval unknown ajax data
*/
Ajax_m.prototype.setRequestResult = function (request_id, data) {
this.server_data[request_id].data = data;
}
/*
* compiles the data from the multi query parts into the array entry referenced by the query_index returned
* from client code calling the multiquery function. This also allows the required callback with a reference id to this data
*/
Ajax_m.prototype.multiRequestFinish = function (multirequestid) {
var requestobj = this.server_data[multirequestid];
var multidata = {};
var compactdata;
for (var i in requestobj.id_list) {
requestobj.data[requestobj.id_list[i]] = this.getRequestResult(i);
this.deleteRequest(i);
}
eval(requestobj.callback + "(" + multirequestid + ")");
}
/*
* finalises multisubmit and runs callback
*/
Ajax_m.prototype.multiSubmitFinish = function (multirequestid) {
var requestobj = this.server_data[multirequestid];
var multidata = {};
var compactdata;
for (var i in requestobj.id_list) {
//requestobj.data[requestobj.id_list[i]] = this.getRequestResult(i);
this.deleteRequest(i);
}
eval(requestobj.callback + "(" + multirequestid + ")");
}
}
答案 2 :(得分：0)
您的代码中有很多重复。与@Datadimension 相反，我没有完全重构您的代码，而是试图向您展示参数化一些表达式和函数的方法：
$(document).ready(function() {
var labcatsubcat1=
$("label[for='id_category1'],#id_category1,label[for='id_subcategory1'],#id_subcategory1 ")
.hide();
$('select[name=subcategory],select[name=subcategory1]')
.html('<option value="Not selected" selected disabled>Select Category...</option>');
// called when category field changes from initial value:
$('#id_group').change(function() {
labcatsubcat1.toggle($(this).val()=='premium');
})
$('#id_category,#id_category1').change(function() {
var $this = $(this), postfix=this.id.match(/1*$/)[0];
if ($this.find('option:selected').index() > 0) {
category_id = $('select[name=category'+postfix+']').val();
request_url = '/get_subcategory/' + category_id + '/';
$.ajax({
url: request_url,
type: "GET",
success: function(data) {
$('select[name=subcategory'+postfix+']').empty();
$.each(data, function(key, value) {
$('select[name=subcategory'+postfix+']').append('<option value="' + key + '">' + value + '</option>');
});
}
})
}
});
["keywords,Keywords,100","description,Description,250"].forEach(e=>{
var[id,nam,len]=e.split(",");
$("label[for='id_"+id+"']").html(nam+" 0/"+len);
$('#id_'+id).keyup(function() {
var charsno = $(this).val().length;
$("label[for='id_"+id+"']").html(nam+" (" + charsno + "/"+len+")");
});
});
});<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>不幸的是，这（还）不是一个工作片段，因为您没有发布您的 HTML ...
关于 postfix 的简短说明：此变量将保存字符串 "1" 或 ""，具体取决于 this 是指 #id_category1 还是#id_category DOM 元素。
答案 3 :(得分：-1)
我要做的一件事就是结合两个AJAX请求。您可以为change处理程序使用多个选择器。像$('#id_category', '#id_category1').change(etc...这样的东西。我相信你可以找到一种方法来准确定位哪一个正在处理哪个请求。您可以为其他函数以及the docs使用多个选择器。
如果文件相对较短（约100 - 200行），我认为您可以将所有内容保存在一个地方。否则，绝对将函数分成文件，然后根据需要require。你可以使用requireJS。