[英]Return to ajax call only after all transactions are completed on nodejs router
我正在嘗試對節點頁面進行ajax調用,該節點頁面根據ajax調用中傳遞的參數對數據庫執行一些操作。 我面臨的問題是,該控件被傳遞回html頁面(我正在使用警報來測試請求完成),該頁面甚至在nodejs端上的所有數據庫事務都已完成之前就啟動了ajax調用。 我添加了一個較小的代碼版本,以更好地理解。
Origin: HTML page
<div id="paramList">
<form action='import/other' method='POST' style='display:none;' id="h_form">
<label><input type="checkbox" value="opt1" />Option 1</label>
<label><input type="checkbox" value="opt2" />Option 2</label>
<label><input type="checkbox" value="opt3" />Option 3</label>
<label><input type="checkbox" value="opt4" />Option 4</label>
<label><input type="checkbox" value="opt5" />Option 5</label>
</form>
</div>
<button onclick="startValidation()">Submit</button>
Handler: JS
function startValidation() {
var paramlist = '';
$("#paramList input[type='checkbox']").each(function() {
if ($(this).is(":checked")) {
paramlist += "'" + $(this).val() + "',";
}
});
paramlist = paramlist.substr(0, paramlist.length - 1);
var req = $.ajax({
url: '/import/validate',
type: 'POST',
data: { paramList: paramlist, fileName: finalName }
})
req.done(function(data, status) {
alert('Data validated successfully. Select Ok to go to validate sheet: ' + status);
var form = $("#h_form");
form.submit();
//redirect to the other page and load data from the latest insert
});
req.fail(function(xOptions, textStatus) {
alert('Error occured!: ' + textStatus);
});
}
服務器端腳本
NodeJS: Router
router.post('/validate',function(req,res){
var paramlist = req.body.paramList;
var fileName = req.body.fileName;
var cli = modImport.parseFile(fileName,paramlist);
res.send(cli);
});
//Import module: modImport.js
module.exports.executeQuery = function(strSQL, operationType, tableName, cb, param) {
logger.log('debug','running query: '+strSQL);
var request = new sql.Request(connection);
request.query(strSQL,function(err, recordset) {
if(err){
logger.error('ERROR in '+operationType+' ON '+tableName+': '+err);
}
logger.info(operationType+' ON '+tableName+' successful!');
if(cb){
cb(param);
}
});
},
module.exports.parseFile: function(filePath, validateParam){
sql.connect(config).then(function() {
var arr = [];
arr.push(data);arr.push(validateParam);
arr.push(tName);
var delQ = "DELETE FROM [Tbl_TempData]";
util.executeQuery(delQ,'DELETION','[Tbl_TempData]', module.exports.bulkImportIntoTempData, arr);
console.log("deletion completed");
}).catch(function(err) {
logger.error('other error: '+err);
});
},
module.exports.bulkImportIntoTempData: function(arr){
var data = arr[0];
var validateParam = arr[1];
var tName = arr[2];
var bInQ = "INSERT INTO [Tbl_TempData] (field1,field2,field3) VALUES ";
data.forEach(function(rec, index){
var keys = Object.keys(rec);
var kLen = keys.length - 1;
keys.forEach(function(datum,cursor){
bInQ += "('" + datum + "','" + rec[datum] + "','" + tName + ")";
if(cursor < kLen){
bInQ += ",";
}
});
});
module.exports.executeQuery(bInQ,'BULK INSERTION','[Omni_TempSurveyData]',module.exports.processForTempCalc,validateParam);
},
module.exports.processForTempCalc: function(validateParam){
var strSQL = "DELETE FROM [Tbl_TempCalc]";
util.executeQuery(strSQL,'DELETION','[Tbl_TempCalc]',module.exports.insertIntoTempCalc,validateParam);
},
module.exports.insertIntoTempCalc: function(validateParam){
var strSQL = "INSERT INTO .....";
//some transformations here from other tables
util.executeQuery(strSQL,'INSERTION','[Tbl_TempCalcData]');
},
module.exports.insertIntoBlankCalc: function(validateParam){
var strSQL = "INSERT INTO .....";
util.executeQuery(strSQL,'INSERTION','[Tbl_BlankCalcData]');
//TODO: return the ajax call
}
在ajax完成之后,將用戶重定向到正在從最后插入的表中加載數據的頁面。 但是由於警報是在最終插入之前彈出的,因此重定向頁面對用戶顯示為空白。 請提出如何克服這種情況的建議。
如果我是對的,那么“ modImport.parseFile”函數不會返回任何內容,而只是在promise中調用“ util.executeQuery”。
所以在這一行“ var cli = modImport.parseFile(fileName,paramlist);” cli未被重視,並引發錯誤;
我認為您應該發送“ res.send(cli)”作為“ modImport.parseFile”作為參數的回調,然后發送給“ util.executeQuery”,否則您應該更改功能
更新:我以這種方式更改了您的代碼。 所以我不能運行它,但我想它將起作用。 希望能幫助到你。
router.post('/validate',function(req,res){
var paramlist = req.body.paramList;
var fileName = req.body.fileName;
var GLOBAL.response_function = function(err,data)
{
//here you can do anything with your data or err;
// like that
if (err)
{
return res.status(404).send(err.toString());
}
else
{
// if your data is json
return res.status(200).send(JSON.stringify(data));
}
};
modImport.parseFile(fileName,paramlist) ;
});
module.exports.executeQuery = function(strSQL, operationType, tableName, cb, param) {
logger.log('debug','running query: '+strSQL);
var request = new sql.Request(connection);
request.query(strSQL,function(err, recordset) {
if(err){
logger.error('ERROR in '+operationType+' ON '+tableName+': '+err);
}
logger.info(operationType+' ON '+tableName+' successful!');
if(cb){
if (param.is_return_callback)
{
cb(err, recordset)
}
else
{
cb(param);
}
}
});
},
關鍵是您應通過執行查詢的最后一個函數發送此“,GLOBAL.response_function,{is_return_callback:true}”
module.exports.insertIntoTempCalc: function(validateParam){
var strSQL = "INSERT INTO .....";
//some transformations here from other tables
util.executeQuery(strSQL,'INSERTION','[Tbl_TempCalcData]',GLOBAL.response_function, {is_return_callback:true});
},
如果其他功能運行正常,將解決問題:
NodeJS: Router
router.post('/validate',function(req,res){
var paramlist = req.body.paramList;
var fileName = req.body.fileName;
var cli = modImport.parseFile(fileName,paramlist,function(){
res.send(cli);
});
});
//Import module: modImport.js
module.exports.executeQuery = function(strSQL, operationType, tableName, cb, param) {
logger.log('debug','running query: '+strSQL);
var request = new sql.Request(connection);
request.query(strSQL,function(err, recordset) {
if(err){
logger.error('ERROR in '+operationType+' ON '+tableName+': '+err);
}
logger.info(operationType+' ON '+tableName+' successful!');
if(cb){
cb(param);
}
});
},
module.exports.parseFile: function(filePath, validateParam,callback){
sql.connect(config).then(function() {
var arr = [];
arr.push(data);arr.push(validateParam);
arr.push(tName);
var delQ = "DELETE FROM [Tbl_TempData]";
util.executeQuery(delQ,'DELETION','[Tbl_TempData]', module.exports.bulkImportIntoTempData, arr);
console.log("deletion completed");
callback()
}).catch(function(err) {
logger.error('other error: '+err);
callback()
});
},
module.exports.bulkImportIntoTempData: function(arr){
var data = arr[0];
var validateParam = arr[1];
var tName = arr[2];
var bInQ = "INSERT INTO [Tbl_TempData] (field1,field2,field3) VALUES ";
data.forEach(function(rec, index){
var keys = Object.keys(rec);
var kLen = keys.length - 1;
keys.forEach(function(datum,cursor){
bInQ += "('" + datum + "','" + rec[datum] + "','" + tName + ")";
if(cursor < kLen){
bInQ += ",";
}
});
});
module.exports.executeQuery(bInQ,'BULK INSERTION','[Omni_TempSurveyData]',module.exports.processForTempCalc,validateParam);
},
module.exports.processForTempCalc: function(validateParam){
var strSQL = "DELETE FROM [Tbl_TempCalc]";
util.executeQuery(strSQL,'DELETION','[Tbl_TempCalc]',module.exports.insertIntoTempCalc,validateParam);
},
module.exports.insertIntoTempCalc: function(validateParam){
var strSQL = "INSERT INTO .....";
//some transformations here from other tables
util.executeQuery(strSQL,'INSERTION','[Tbl_TempCalcData]');
},
module.exports.insertIntoBlankCalc: function(validateParam){
var strSQL = "INSERT INTO .....";
util.executeQuery(strSQL,'INSERTION','[Tbl_BlankCalcData]');
//TODO: return the ajax call
}
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