Javascript malfunction - javascript

can someone explain me why this script is not working?
<script type="text/javascript">
function destroy(ID) {
if (confirm("Deleting is a very bad thing! Sure?"))
{
location.href='#Url.Action("SomeAction", new { id = ID })'
}
}
The error is: The name 'ID' does not exist in the current context, and occures here new { id = ID }
If I just replace ID in this way: new { id = 3 } it works fine. What is the problem?

You mix your Server code with the client code.
ID is a javascript variable- exist only on the client.
#Url.Action("SomeAction", server code, Exist only on the server.
You can't mix them!
You can do something like this:
function destroy(ID) {
if (confirm("Deleting is a very bad thing! Sure?")){
var url ='#Url.Action("SomeAction")';
url += '/?id =' + ID;
location.href = url;
}
}
You have to remember all the # stuff in the views are compiled and executed in the server and no longer exist in the client. tricky razor...
By the way, I would have change the confirm message...

Related

Flaskr url_for with javascript variable as parameters is not working to python

I'm trying to use flask with url_for. The problem is that when I try to launch an alert with the value of the javascript variable everything seems ok, but when I try to launch a alert with the url_for the content of the variable is not printed. What I'm doing wrong? or What is missing in my code?
How can I pass a JavaScript variable into the url_for function?
html code:
<a class="dissable_user_btn" data-user_id="{{user.id}}" href="#" title="Change Status"><i class="fa fa-plug"></i>
</a>
JS Code:
<script type="text/javascript">
$(document).ready(function(){
$('.dissable_user_btn').click(function( event ) {
var user_id = $(this).data("user_id")
alert(user_id) //everything ok
alert ('{{url_for('.dissable', _id=user_id)}}'); //dont print the valur of user_id
</script>
Short answer: you can't. Flask & Jinja2 render the template on the server side (e.g. Flask is translating all of the {{ }} stuff before it sends the HTML to the web browser).
For a URL like this where you're including a variable as part of the path you'd need to build this manually in javascript. If this is an XHR endpoint I'd recommend using GET/POST to transfer the values to the server as a better best practice than constructing the URL this way. This way you can use Jinja:
$(document).ready(function(){
var baseUrl = "{{ url_for('disable') }}";
$('.dissable_user_btn').click(function(event) {
var user_id = $(this).data("user_id");
// first part = url to send data
// second part = info to send as query string (url?user=user_id)
// third parameter = function to handle response from server
$.getJSON(baseUrl, {user: user_id}, function(response) {
console.log(response);
});
});
});
I found another solution for this. My problem started when I needed to pass a variable with space.
First I created a function to remove trailing and leading spaces
function strip(str) {
return str.replace(/^\s+|\s+$/g, '');}
After that, I used the function and encoded the URL
<script type="text/javascript">
$(document).ready(function(){
$('.dissable_user_btn').click(function( event ) {
var user_id = $(this).data("user_id")
alert(user_id)
user_id = strip(user_id).replace(" ","%20");
alert ('{{url_for('.dissable', _id='user_id')}}.replace('user_id',user_id);
</script>
It worked pretty nice for me!
This is how I applied to my problem
<script>
function strip(str) {
return str.replace(/^\s+|\s+$/g, '');}
$(document).ready(function() {
$('#exportcountry').click(function() {
var elemento = document.getElementById("countryexportbtn");
var country = strip(elemento.textContent).replace(" ","%20");
$('#exportevent').load("{{ url_for('get_events',country = 'pais') }}".replace('pais',country));
});
});
</script>

CasperJS; opening dynamic url

I am using casperJS to got ta a page and collect an id from the URL, this is what my start function is doing. I would then like to put the id in to a new url and go there.
This works for the user var, this is coming in from the terminal. However sid is undefined and not the value I updated it to.
Any help would be appreciated. I am wondering if I found a limitation with casperJS. please not that this is not the full code (as that is much longer), if you message me I can provide you the whole script.
var user = decodeURIComponent(casper.cli.get(0).replace(/\+/g, ' '))
var sid
casper.start('https://editor.storify.com/', function() {
sid = this.getCurrentUrl()
sid = sid.split('/')[3]
})
casper.thenOpen('https://storify.com/' + sid, function() {
console.log('lets view the posts')
console.log(token)
console.log(sid)
if (dev)
this.capture('storeheading.png')
})
you can solve this problem by warping the thenOpen inside of a then
casper.then(function() {
casper.thenOpen('https://storify.com/' + sid, function() {
console.log('lets view the posts')
console.log(token)
console.log(sid)
if (dev)
this.capture('storeheading.png')
})
})

Is there a very simple way to update a page in Perl Dancer using jQuery/AJAX?

I have the following code in my main Dancer app .pm:
package Deadlands;
use Dancer ':syntax';
use Dice;
our $VERSION = '0.1';
get '/' => sub {
my ($dieQty, $dieType, $bonus);
my $button = param('button');
$dieQty = param('dieQty');
$dieType = param('dieType');
$bonus = param('bonus');
if (defined $dieQty && defined $dieType) {
return Dice::Dice->new(dieType => $dieType, dieQty => $dieQty, bonus => $bonus)->getStandardResult();
}
template 'index';
};
true;
Here is my JavaScript:
$(document).ready(function() {
$('#standardRoll').click(function() {
$.get("/lib/Deadlands.pm", { button: '1', dieType: $("#dieType").val(), dieQty: $("#dieQty").val(), bonus: $("#bonus").val() }, processData);
function processData(data) {
$("#result").html(data);
}
});
});
I have a div in my web page called result that I want to be updated with the die roll result from Perl. Dancer keeps coming back with a 404 error in the command window when I push the submit button.
/lib/Deadlands.pm needs to be the URL of your route (probably / in this case), not the filesystem path of your Perl module.
Your AJAX request needs to point to a URL that actually exists, not a filename that has nothing to do with the web. Looks like $.get('/', ...) would do in this case.

Is it possible to ping a server from Javascript?

I'm making a web app that requires that I check to see if remote servers are online or not. When I run it from the command line, my page load goes up to a full 60s (for 8 entries, it will scale linearly with more).
I decided to go the route of pinging on the user's end. This way, I can load the page and just have them wait for the "server is online" data while browsing my content.
If anyone has the answer to the above question, or if they know a solution to keep my page loads fast, I'd definitely appreciate it.
I have found someone that accomplishes this with a very clever usage of the native Image object.
From their source, this is the main function (it has dependences on other parts of the source but you get the idea).
function Pinger_ping(ip, callback) {
if(!this.inUse) {
this.inUse = true;
this.callback = callback
this.ip = ip;
var _that = this;
this.img = new Image();
this.img.onload = function() {_that.good();};
this.img.onerror = function() {_that.good();};
this.start = new Date().getTime();
this.img.src = "http://" + ip;
this.timer = setTimeout(function() { _that.bad();}, 1500);
}
}
This works on all types of servers that I've tested (web servers, ftp servers, and game servers). It also works with ports. If anyone encounters a use case that fails, please post in the comments and I will update my answer.
Update: Previous link has been removed. If anyone finds or implements the above, please comment and I'll add it into the answer.
Update 2: #trante was nice enough to provide a jsFiddle.
http://jsfiddle.net/GSSCD/203/
Update 3: #Jonathon created a GitHub repo with the implementation.
https://github.com/jdfreder/pingjs
Update 4: It looks as if this implementation is no longer reliable. People are also reporting that Chrome no longer supports it all, throwing a net::ERR_NAME_NOT_RESOLVED error. If someone can verify an alternate solution I will put that as the accepted answer.
Ping is ICMP, but if there is any open TCP port on the remote server it could be achieved like this:
function ping(host, port, pong) {
var started = new Date().getTime();
var http = new XMLHttpRequest();
http.open("GET", "http://" + host + ":" + port, /*async*/true);
http.onreadystatechange = function() {
if (http.readyState == 4) {
var ended = new Date().getTime();
var milliseconds = ended - started;
if (pong != null) {
pong(milliseconds);
}
}
};
try {
http.send(null);
} catch(exception) {
// this is expected
}
}
you can try this:
put ping.html on the server with or without any content, on the javascript do same as below:
<script>
function ping(){
$.ajax({
url: 'ping.html',
success: function(result){
alert('reply');
},
error: function(result){
alert('timeout/error');
}
});
}
</script>
You can't directly "ping" in javascript.
There may be a few other ways:
Ajax
Using a java applet with isReachable
Writing a serverside script which pings and using AJAX to communicate to your serversidescript
You might also be able to ping in flash (actionscript)
You can't do regular ping in browser Javascript, but you can find out if remote server is alive by for example loading an image from the remote server. If loading fails -> server down.
You can even calculate the loading time by using onload-event. Here's an example how to use onload event.
Pitching in with a websocket solution...
function ping(ip, isUp, isDown) {
var ws = new WebSocket("ws://" + ip);
ws.onerror = function(e){
isUp();
ws = null;
};
setTimeout(function() {
if(ws != null) {
ws.close();
ws = null;
isDown();
}
},2000);
}
Update: this solution does not work anymore on major browsers, since the onerror callback is executed even if the host is a non-existent IP address.
To keep your requests fast, cache the server side results of the ping and update the ping file or database every couple of minutes(or however accurate you want it to be). You can use cron to run a shell command with your 8 pings and write the output into a file, the webserver will include this file into your view.
The problem with standard pings is they're ICMP, which a lot of places don't let through for security and traffic reasons. That might explain the failure.
Ruby prior to 1.9 had a TCP-based ping.rb, which will run with Ruby 1.9+. All you have to do is copy it from the 1.8.7 installation to somewhere else. I just confirmed that it would run by pinging my home router.
There are many crazy answers here and especially about CORS -
You could do an http HEAD request (like GET but without payload).
See https://ochronus.com/http-head-request-good-uses/
It does NOT need a preflight check, the confusion is because of an old version of the specification, see
Why does a cross-origin HEAD request need a preflight check?
So you could use the answer above which is using the jQuery library (didn't say it) but with
type: 'HEAD'
--->
<script>
function ping(){
$.ajax({
url: 'ping.html',
type: 'HEAD',
success: function(result){
alert('reply');
},
error: function(result){
alert('timeout/error');
}
});
}
</script>
Off course you can also use vanilla js or dojo or whatever ...
If what you are trying to see is whether the server "exists", you can use the following:
function isValidURL(url) {
var encodedURL = encodeURIComponent(url);
var isValid = false;
$.ajax({
url: "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22" + encodedURL + "%22&format=json",
type: "get",
async: false,
dataType: "json",
success: function(data) {
isValid = data.query.results != null;
},
error: function(){
isValid = false;
}
});
return isValid;
}
This will return a true/false indication whether the server exists.
If you want response time, a slight modification will do:
function ping(url) {
var encodedURL = encodeURIComponent(url);
var startDate = new Date();
var endDate = null;
$.ajax({
url: "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22" + encodedURL + "%22&format=json",
type: "get",
async: false,
dataType: "json",
success: function(data) {
if (data.query.results != null) {
endDate = new Date();
} else {
endDate = null;
}
},
error: function(){
endDate = null;
}
});
if (endDate == null) {
throw "Not responsive...";
}
return endDate.getTime() - startDate.getTime();
}
The usage is then trivial:
var isValid = isValidURL("http://example.com");
alert(isValid ? "Valid URL!!!" : "Damn...");
Or:
var responseInMillis = ping("example.com");
alert(responseInMillis);
const ping = (url, timeout = 6000) => {
return new Promise((resolve, reject) => {
const urlRule = new RegExp('(https?|ftp|file)://[-A-Za-z0-9+&##/%?=~_|!:,.;]+[-A-Za-z0-9+&##/%=~_|]');
if (!urlRule.test(url)) reject('invalid url');
try {
fetch(url)
.then(() => resolve(true))
.catch(() => resolve(false));
setTimeout(() => {
resolve(false);
}, timeout);
} catch (e) {
reject(e);
}
});
};
use like this:
ping('https://stackoverflow.com/')
.then(res=>console.log(res))
.catch(e=>console.log(e))
I don't know what version of Ruby you're running, but have you tried implementing ping for ruby instead of javascript? http://raa.ruby-lang.org/project/net-ping/
let webSite = 'https://google.com/'
https.get(webSite, function (res) {
// If you get here, you have a response.
// If you want, you can check the status code here to verify that it's `200` or some other `2xx`.
console.log(webSite + ' ' + res.statusCode)
}).on('error', function(e) {
// Here, an error occurred. Check `e` for the error.
console.log(e.code)
});;
if you run this with node it would console log 200 as long as google is not down.
You can run the DOS ping.exe command from javaScript using the folowing:
function ping(ip)
{
var input = "";
var WshShell = new ActiveXObject("WScript.Shell");
var oExec = WshShell.Exec("c:/windows/system32/ping.exe " + ip);
while (!oExec.StdOut.AtEndOfStream)
{
input += oExec.StdOut.ReadLine() + "<br />";
}
return input;
}
Is this what was asked for, or am i missing something?
just replace
file_get_contents
with
$ip = $_SERVER['xxx.xxx.xxx.xxx'];
exec("ping -n 4 $ip 2>&1", $output, $retval);
if ($retval != 0) {
echo "no!";
}
else{
echo "yes!";
}
It might be a lot easier than all that. If you want your page to load then check on the availability or content of some foreign page to trigger other web page activity, you could do it using only javascript and php like this.
yourpage.php
<?php
if (isset($_GET['urlget'])){
if ($_GET['urlget']!=''){
$foreignpage= file_get_contents('http://www.foreignpage.html');
// you could also use curl for more fancy internet queries or if http wrappers aren't active in your php.ini
// parse $foreignpage for data that indicates your page should proceed
echo $foreignpage; // or a portion of it as you parsed
exit(); // this is very important otherwise you'll get the contents of your own page returned back to you on each call
}
}
?>
<html>
mypage html content
...
<script>
var stopmelater= setInterval("getforeignurl('?urlget=doesntmatter')", 2000);
function getforeignurl(url){
var handle= browserspec();
handle.open('GET', url, false);
handle.send();
var returnedPageContents= handle.responseText;
// parse page contents for what your looking and trigger javascript events accordingly.
// use handle.open('GET', url, true) to allow javascript to continue executing. must provide a callback function to accept the page contents with handle.onreadystatechange()
}
function browserspec(){
if (window.XMLHttpRequest){
return new XMLHttpRequest();
}else{
return new ActiveXObject("Microsoft.XMLHTTP");
}
}
</script>
That should do it.
The triggered javascript should include clearInterval(stopmelater)
Let me know if that works for you
Jerry
You could try using PHP in your web page...something like this:
<html><body>
<form method="post" name="pingform" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<h1>Host to ping:</h1>
<input type="text" name="tgt_host" value='<?php echo $_POST['tgt_host']; ?>'><br>
<input type="submit" name="submit" value="Submit" >
</form></body>
</html>
<?php
$tgt_host = $_POST['tgt_host'];
$output = shell_exec('ping -c 10 '. $tgt_host.');
echo "<html><body style=\"background-color:#0080c0\">
<script type=\"text/javascript\" language=\"javascript\">alert(\"Ping Results: " . $output . ".\");</script>
</body></html>";
?>
This is not tested so it may have typos etc...but I am confident it would work. Could be improved too...

How to use jquery to decode the return json object?

I trid to use an upload plugin for jQuery.
http://valums.com/ajax-upload/
When I set the returning respond type to json, firefox will popup a dialog asking how I like to handle the returning json object.
People have asked the same question at the upload script's author's page but no answer so far. Hopefully javascript guys here can figure out how we can handle this.
Thanks.
<script type= "text/javascript">
/*<![CDATA[*/
$(document).ready(function(){
/* example 1 */
var button = $('#button1'), interval;
new AjaxUpload(button, {
//action: 'upload-test.php', // I disabled uploads in this example for security reasons
action: '/posts/upload_images/',
name: 'myfile',
responseType: 'json',
onSubmit : function(file, ext){
// change button text, when user selects file
button.text('Uploading');
// If you want to allow uploading only 1 file at time,
// you can disable upload button
this.disable();
// Uploding -> Uploading. -> Uploading...
interval = window.setInterval(function(){
var text = button.text();
if (text.length < 13){
button.text(text + '.');
} else {
button.text('Uploading');
}
}, 200);
},
onComplete: function(file, response){
var json = response;
alert(json);
button.text('Upload');
window.clearInterval(interval);
// enable upload button
this.enable();
// add file to the list
// $('<li></li>').appendTo('#example1 .files').text(json.response_text);
$('<li></li>').appendTo('#example1 .files').text(file);
}
});
});
/*]]>*/
</script>
http://api.jquery.com/jQuery.parseJSON/
var obj = jQuery.parseJSON('{"name":"John"}');
alert( obj.name === "John" );
This jQuery plugin makes it simple to convert to and from JSON: http://code.google.com/p/jquery-json/
Also, you might be interested in this comment on the blog post you referenced:
Sorry to spam your blog post (which is great), but I thought I’d mention that I found the problem:
For whatever reason, the response always has <pre> tags around the entire response when the response is of type plain/text. That was causing the eval() call to fail. My current solution was just to strip those tags off before the eval() call and now everything works. Not a great solution but at least I can keep working for now.
I was looking for a solution for the same script and stumbled upon this page. I didn't found a solution online so here's how I fixed it:
# upload-file.php:
replace
echo "success".$cc;
with
echo json_encode(array(
status' => 'success',
'id' => $picid,
'image' => $imgurl
));
# front end:
replace
var bb=response.substr(0,7)
var idd=response.replace('success',' ');
var idb =idd.replace(/^\s*|\s*$/g,'');
if(bb==="success")
{
$('<span></span>').appendTo('#files').html('<img src="images/'+file+'" alt="" width="120" height="120" style="margin:5px;" />').addClass('success');
}
else
{
$('<span></span>').appendTo('#files').text(file).addClass('error');
}
with
var what = jQuery.parseJSON(response);
if(what.status == 'success')
{
$('<span id='+what.id+'></span>').appendTo('#files').html('<img src="'+what.image+'" alt="" width="120" height="120" style="margin:5px;" /><br>Delete').addClass('success');
}
else
{
$('<span></span>').appendTo('#files').text(response).addClass('error');
}
And to actually answer this question.
jQuery.parseJSON(response);
does..
This may be it, I don't know because I know nothing about that plugin, but you may need to take a look at the response type you are setting on the server-side of things; you should set the HTTP response to have a content/MIME type of something like "text/plain", "text/javascript" or "application/javascript" - see if that fixes your problem.

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