我在一个应用程序上放置一个验证组件，它接受一个任务名称（可以是一个字段名称）和一个值作为它的参数。对于每个找到的表单字段，都会启动任务。
如果验证失败，则返回错误，否则输入正常，下一个字段任务将启动，直到处理完所有字段。
通过下面的示例，task_1按预期工作。但是，如果可能需要 HTTP 请求（由setTimeout模拟），则task_2不会返回所需的结果。
我确信这与异步性有关，也许有更好的方法来实现这种机制。这实际上将在{strong> NodeJS 后端实现，async库可用，我会接受使用Async的解决方案。
请参阅以下Fiddle以获取以下示例。或者这个{{3}}用于异步实现。
/**
* Selecting task_1 below, will have the desired results,
* however if you run task_2 the final task will not work?
* A setTimeout() has been used to simulate a HTTP request etc..
*/
// output element
var $output = $$('output')
// configuration object, each task has an
// array of functions which must accept a
// value which would be validated
var jobs = {
task_1: [
function(val, cb) {
cb(null, val)
},
function(val, cb) {
cb('Error', null)
}
],
task_2: [
function(val, cb) {
cb(null, val)
},
function(val, cb) {
setTimeout(function() {
cb('An ajax request has an error', null)
}, 2000)
}
]
}
// run a task and pass a value
taskRunner('task_2', 'Karl')
// taskRunner
function taskRunner(job, val) {
var tasks = jobs[job]
var errors = []
if (tasks) {
// run the found tasks
for (i = 0; i < jobs[job].length; i++) {
tasks[i](val, function(err, result) {
if (err) {
errors.push(err)
}
})
}
// generate the html output
var html = errors.length > 0 ? [
'<strong class="text-danger">',
'Failure</strong>',
'<pre>',
errors,
'</pre>'
].join('') : [
'<strong class="text-success">',
'Success</strong>',
'<pre>All validations passed</pre>'
].join('')
$output.html(html).fadeIn()
} else {
// return an error message if no tasks have been found
$output.html('<span class="text-danger">There are no tasks for ' + job + '.</span>').fadeIn()
}
}
// select elements by data attribute
function $$(val) {
return $('[data-' + val + ']')
}/* default */
html,
body {
margin: 0;
padding: 0;
font-family: "Lucida Console", Monaco, monospace !important;
background: whitesmoke;
color: #333;
}
/* output container */
.output {
max-width: 75%;
margin: 5% auto;
padding: 15px;
border: 1px solid #ddd;
border-radius: 3px;
background: white;
box-shadow: 0 1px 2px rgba(0, 0, 0, .075);
}
/* formatted output */
pre {
background: #FAFAFA;
padding: 15px;
margin-bottom: 0;
}
/* type styles */
.text-muted {
opacity: .5
}
.text-danger {
color: #D00
}
.text-success {
color: #0D0
}
/* hide if empty */
.js-hide {
display: none
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="output js-hide" data-output></div>
答案 0 :(得分：1)
你应该在完成所有回调后生成html输出
为此目的，您可以使用promise.all
但是对于回调，您可以使用此代码
var doneCallback=0;
for (i = 0; i < jobs[job].length; i++) {
tasks[i](val, function(err, result) {
if (err) {
errors.push(err)
}
doneCallback++;
if(doneCallback==jobs[job].length)generateHtml();
})
}
// generate the html output
function generateHtml(){
var html = errors.length > 0 ? [
'<strong class="text-danger">',
'Failure</strong>',
'<pre>',
errors,
'</pre>'
].join('') : [
'<strong class="text-success">',
'Success</strong>',
'<pre>All validations passed</pre>'
].join('')
$output.html(html).fadeIn();
}
/**
* Selecting task_1 below, will have the desired results,
* however if you run task_2 the final task will not work?
* A setTimeout() has been used to simulate a HTTP request etc..
*/
// output element
var $output = $$('output')
// configuration object, each task has an
// array of functions which must accept a
// value which would be validated
var jobs = {
task_1: [
function(val, cb) {
cb(null, val)
},
function(val, cb) {
cb('Error', null)
}
],
task_2: [
function(val, cb) {
cb(null, val)
},
function(val, cb) {
setTimeout(function() {
cb('An ajax request has an error', null)
}, 2000)
}
]
}
// run a task and pass a value
taskRunner('task_2', 'Karl')
// taskRunner
function taskRunner(job, val) {
var tasks = jobs[job]
var errors = []
if (tasks) {
// run the found tasks
var doneCallback=0;
for (i = 0; i < jobs[job].length; i++) {
tasks[i](val, function(err, result) {
if (err) {
errors.push(err)
}
doneCallback++;
if(doneCallback==jobs[job].length)generateHtml();
})
}
// generate the html output
function generateHtml(){
var html = errors.length > 0 ? [
'<strong class="text-danger">',
'Failure</strong>',
'<pre>',
errors,
'</pre>'
].join('') : [
'<strong class="text-success">',
'Success</strong>',
'<pre>All validations passed</pre>'
].join('')
$output.html(html).fadeIn();
}
} else {
// return an error message if no tasks have been found
$output.html('<span class="text-danger">There are no tasks for ' + job + '.</span>').fadeIn()
}
}
// select elements by data attribute
function $$(val) {
return $('[data-' + val + ']')
}/* default */
html,
body {
margin: 0;
padding: 0;
font-family: "Lucida Console", Monaco, monospace !important;
background: whitesmoke;
color: #333;
}
/* output container */
.output {
max-width: 75%;
margin: 5% auto;
padding: 15px;
border: 1px solid #ddd;
border-radius: 3px;
background: white;
box-shadow: 0 1px 2px rgba(0, 0, 0, .075);
}
/* formatted output */
pre {
background: #FAFAFA;
padding: 15px;
margin-bottom: 0;
}
/* type styles */
.text-muted {
opacity: .5
}
.text-danger {
color: #D00
}
.text-success {
color: #0D0
}
/* hide if empty */
.js-hide {
display: none
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="output js-hide" data-output></div>
答案 1 :(得分：0)
awk -v line='DELIMITER AS '"'|'"'' '1; /LOAD_FILE/{print line }' input
FROM LOCAL :LOAD_FILE
DELIMITER AS '|'
REJECTED DATA :REJECT_PATH