Code JS encapsulation Ajax cascade drop-down list

1 // trigger all links when a drop-down list changes. (warning: Do not use circular dependencies between the drop-down lists.) 2 // This function complies with the following specifications: no memory data is used (all data is used in real time, real-time retrieval, and real-time data), and registration is not initialized. 3 // This specification can cause any exceptions in HTML, maintain the best stability 4 function refreshlinkage (ddlctrl) {5 var curid =! Ddlctrl? "": Ddlctrl. ID; 6 // If (curid = undefined | curid. replace ("",""). length <= 0) return; // If the refresh control is not specified, refresh all controls 7 // var curvalue = ddlctrl. value; // after triggering, let the child control find the desired value: the current value is 8 9 If (curid & ddlctrl) {10 var hfvaluectrlid = $ (ddlctrl ). ATTR ("valuectrlid"); 11 if (! Hfvaluectrlid) hfvaluectrlid = "HF _" + curid; 12 $ ("#" + hfvaluectrlid ). val ($ (ddlctrl ). val (); 13} 14 15 $ ("select "). each (function (index, ELEM) {16 if (! Curid | ELEM. ID! = Curid) {// refresh all or do not link yourself 17 var parentid = $ (ELEM). ATTR ("parentid"); 18 if (parentid! = Undefined & ("" + parentid ). replace ("",""). length> 0) {19 var parentids = parentid. split (','); // split parent ID 20 if (! Curid | parentids. indexof (curid)> = 0) {// If a control is linked by the current control 21 // The operation is linked to the subcontrol 22 refreshoptions (ELEM ); 23} 24} 25} 26}); 27 28 // refresh the specified drop-down list 29 function refreshoptions (ELEM) {30 if (! ELEM |! ELEM. ID) return; 31 32 var parentid = $ (ELEM ). ATTR ("parentid"); 33 var parentkey = $ (ELEM ). ATTR ("parentkey"); 34 if (! Parentid |! Parentkey) return; 35 36 var parentids = parentid. Split (','); 37 var parentkeys = parentkey. Split (','); 38 39 if (parentkeys. length! = Parentids. Length) 40 throw new error ("linkage select \" "+ ELEM. ID +" \ ": 'parentkey' and 'parentid' length is not same! "); 41 42 var elemvalueid = $ (ddlctrl). ATTR (" valuectrlid "); 43 If (! Elemvalueid) elemvalueid = "HF _" + ELEM. ID; 44 45 46 // clear the drop-down list 47 if ($ (ELEM ). find ("option "). length> 0) 48 $ ("#" + elemvalueid ). val (''); 49 $ (ELEM ). find ("option "). remove (); 50 51 // create the default row 52 var withempty = $ (ELEM ). ATTR ("withempty ")! = "False"; 53 var emptyvalue = ($ (ELEM ). ATTR ("emptyvalue") | ''); 54 var emptytext = ($ (ELEM ). ATTR ("emptytext") | (getsettingvalue ("isenglish", true ))? "Please select": "select"); 55 if (withempty) {56 $ (ELEM ). append ("<option value = '{v}'> {t} </option> ". replace ("{v}", emptyvalue ). replace ("{t}", emptytext); 57} 58 59 60 // the required data 61 var parentisempty = true; 62 var jsonstr = "{\" _ Action \ ": \" refreshselect \ ", \" _ selectctrl \ ": \" "+ ELEM. ID + "\", "; 63 for (var j = 0; j <parentkeys. length; j ++) {64 var parentvalue = ($ ("#" + parentids [J]). val () | ''); 65 jsonstr = jsonstr +" \ "" + parentkeys [J] + "\": \ "" + parentvalue + "\" "+ (j = parentkeys. length-1? "": ","); 66 If (parentvalue & parentvalue! = Emptyvalue) parentisempty = false; 67} 68 jsonstr = jsonstr + "}"; 69 70 71 // if no data exists at the parent level, no Ajax 72 If (parentisempty) is performed) return; 73 74 75 // Ajax submit 76 var jsondata = JSON. parse (jsonstr); 77 var posturl = ($ (ELEM ). ATTR ("posturl") | (window. location. href); // If the post address is not specified, it will point to its own page 78 posturl = posturl + (posturl. indexof ("? ")> = 0? ("& _ RD =" + math. Random ()):("? _ RD = "+ math. random (); // prevents caching 79 $. post (posturl, jsondata, 80 function (data, status) {81 // alert ("data:" + Data + "\ nstatus:" + status); 82 If (Data! = Undefined & data. length> 0) {83 // dynamically obtained row 84 var optiontemp = ($ (ELEM ). ATTR ("optiontemp") | "<option value = '{v}'> {t} </option>"); 85 $. each (data, function (itemindex, itemelem) {86 var html = perfectexpres (optiontemp, itemelem); 87 $ (ELEM ). append (HTML); 88}); 89 90 // assign the value of the hidden control to the drop-down list control 91 var $ valuectrl =$ ("#" + elemvalueid ); 92 if ($ valuectrl. length> 0) 93 $ (ELEM ). val ($ valuectrl. val (); 94 95 // The change event that triggers this changed drop-down list 96 refreshlinkage (ELEM); 97} 98}, "JSON "); 99} 100 101 // all attributes in the cyclic object, replacing the corresponding part in expres; 102 function perfectexpres (expres, object) {103 for (var key in object) {104 expres = expres. replace ("{" + key + "}", (object [Key] | ''); 105} 106 return expres; 107} 108}