I used several editors for javaScript and i write
var firstName = "John";
console.log(firstName);
problem is that i do not get console.log in Chrome (or other browser)
anyone knows what might happening?
Simply writing:
var firstName = "John"; console.log(firstName);
Isn't enough for javascript to run. Javascript is a scripting language meaning you need to provide some other infrastructure for it to work. In this case that infrastructure is HTML. You can use HTML and Javascript together like so:
<!DOCTYPE html>
<html>
<script>
var firstName = "John"; console.log(firstName);
</script>
</html>
The script tags indicate that you are writing Javascript. Save this file as a .html file and then right-click your file and click view in chrome. Then check the console for results
Check:
You have saved the file (something like index.html)
You have the correct file open in the browser
You have put the js inside a script tag
Related
The powers that be have asked me to look into this and as much as I think it's not possible I want to be sure before going back to them. Don't ask me why they want this haha
They want to be able to use JavaScript that is defined in a variable. Let me explain...
Let's say you have this variable:
var testvar = "function dan() { alert('hello world'); }";
They want to be able to call dan() and have an alert popup in the web page. Something like this doesn't appear to be useable (of course).
var importjs = document.createElement('script');
importjs.src = testvar;
document.getElementsByTagName("head")[0].appendChild(importjs);
Any ideas or jargon I can use to explain why it's not doable. I believe it's essentially a cross origin issue. Our solution requires users to install software, which uses web sockets. This software performs a file GET for the JS and we then want to use the JS in the browser.
You should set the innerHTML of the script element to your String. The src of a script element should only be used to load an external script.
var testvar = "function dan() { alert('hello world'); }";
var importjs = document.createElement('script');
importjs.innerHTML = testvar;
document.getElementsByTagName("head")[0].appendChild(importjs);
dan();
I want to make a JQuery routine that can write information (append) to a text file that either exists or does not exists. If the file does not exists than it should create the file and if it does it should either append or start writing new data to the file. I think append would be the best choice for a file logger. So it must append the data to the file.
I found this code on the internet and am trying to work it around so that I can use it on my page to write information to a simple text file.
Question: How can I make the following code log to a file for download?
Below is the new code and how I read the page that was listed in the comments on how a logger in Java script should work. The code is not working and I am not really certain as to why.
I am not really certain as to how the download works either but if I can just get the logger to work I will be happy for the time being.
Code:
<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js">
<script src="log4moz.js">
</head>
<script>
getLocalDirectory : function() {
let directoryService = Cc["#mozilla.org/file/directory_service;1"].getService(Ci.nsIProperties);
// this is a reference to the profile dir (ProfD) now.
let localDir = directoryService.get("ProfD", Ci.nsIFile);
localDir.append("XULSchool");
if (!localDir.exists() || !localDir.isDirectory()) {
// read and write permissions to owner and group, read-only for others.
localDir.create(Ci.nsIFile.DIRECTORY_TYPE, 0774);
}
return localDir;
}
let myFile = XULSchool.getLocalDirectory();
myFile.append("someFile.txt");
let formatter = new Log4Moz.BasicFormatter();
let root = Log4Moz.repository.rootLogger;
let logFile = this.getLocalDirectory(); // remember this?
let appender;
logFile.append("log.txt");
root.level = Log4Moz.Level["All"];
appender = new Log4Moz.RotatingFileAppender(logFile, formatter);
appender.level = Log4Moz.Level["All"];
root.addAppender(appender);
this._logger = Log4Moz.repository.getLogger("XULSchool.SomeObject");
this._logger.level = Log4Moz.Level["All"];
this._logger.fatal("This is a fatal message.");
this._logger.error("This is an error message.");
this._logger.warn("This is a warning message.");
this._logger.info("This is an info message.");
this._logger.config("This is a config message.");
this._logger.debug("This is a debug message.");
this._logger.trace("This is a trace message.");
</script>
<body>
<form id="addnew">
<input type="text" class="A">
<input type="text" class="B">
<input type="submit" value="Add">
</form>
</body>
</html>
#Smeegs says this nicely
Imagine a world where any website can edit files on your computer
JavaScript (or jQuery) cannot touch the user's file system.
Even if you find some hacked up thing that works via ActiveXObject, you should not attempt to do this. Cross-browser support would be very narrow for this feature.
If you want to write out file, just provide the user with a download.
If this is just a means of reading/writing some kind of data, look into localstorage.
"wget http://www.example.com/file.doc" downloads that file to the local disk.
What is the equivalent of the above in javascript? for example, consider the following html snippet.
<html>
<head>
<script language="JavaScript">
function download_file() {
var url = "http://www.example.com/file.doc"
//
// Question:
//
// what should be done here to download
// the file in the url?
//
}
</script>
</head>
<body>
<input type="button" value="Download" onclick="download_file()">
</body>
</html>
Please suggest a solution that is compliant with all the browsers.
Sangeeth.
After a exploring more than a month, with a help of my friend, we were able to find out the following.
The website where the file is hosted is not allowing us to download the file using window.location = url; or window.open(url);
Finally we had to use the data-downloadurl support from HTML5 as follows
Click here to download the file
We embed this html into the host html and when clicked on the link, it triggers the download.
Why not use:
function download_file() {
var url = "http://www.example.com/file.doc"
window.location = url;
}
See https://developer.mozilla.org/en/DOM/window.location
If you need to open this in a new window/tab first then use:
function download_file() {
var url = "http://www.example.com/file.doc"
window.open(url);
}
See https://developer.mozilla.org/en/DOM/window.open
First thing that always comes in mind of every answerer to this question is executing wget shell command from java script.I'm almost certain that that's not possible because of
major security risk.
You pretty much need to have ajax which sends command to command line
either through php, or another scripting language via ajax...
You could probably make that happen with something like http://www.phantomjs.org/
I am saying probably because I read it from somewhere.
I am loading a script using the script embed tag and I want to get the url variables and the loading script name inside the script. Is it possible? For Example,
<script src="test.js?id=12"></script>
Inside test.js is there any way to get the url variable id?
Any help would be appreciated.
Thanks,
Karthik
Aside from the answers in the linked post, FWIW with Firefox 4 only you can (with caveats); document.currentScript.src which will return the full url, including arguments.
Thanks for all your efforts I have made that working by assigning an id attribute in the script tag and accessed via jQuery,
<script src="test.js?id=12" id="myScript"></script>
var currentScript = $("#myScript").attr('src'); //This will give me my script src
Thanks,
Karthik
If you want to get a variable from the current URL you can use this:
function queryParser(url){
this.get=function(p){return this.q[p];}
this.q={};
this.map=function(url){
url=url || window.location.search.substring(1);
var url=url.split('&');
var part;
for(var i=0;i<url.length;i++){
part=url[i].split('=');
this.q[part[0]]=part[1];
}
}
this.map(url);
}
var query=new queryParser();
// assuming you have ?test=something
alert(query.get('test'));
I recommend you map the result, so you don't re-parse whenever you want to find a specific element.
I don't really know why you'd pass a query string in a script tag like that, unless you specifically want off-site includes with a simple robust system for various effects. Or are actually using PHP to handle that request.
If you want to "send" a variable to one of your scripts, you can always do:
<script type="text/javascript">
var myVar="I'm in global scope, all scripts can access me";
</script>
<script src="test.js?id=12"></script>
If you really need to get the URL of the currently included script, you can use the code supplied by my peers in the other answers, you can then use:
var query=new queryParser(scriptURL);
alert(query.get('id'));// would alert 12 in your case
Navigating through the link on your comments you can get the proper answer.
Anyway, to make things easier:
var allScripts=document.getElementsByTagName('script');
var indexLastScript= allScripts.length -1;
alert (allScripts[indexLastScript].src);
This will show up "test.js?id=12" as a regular String so its up to you to split it in order to get de param.
Hope it helps, I've tried it on the run over the Chrome Javascript Console. :D.
is it possible to create a file on localhost with javascript?
Not in a webpage. If you're using Windows Script Host then yes you can through ActiveX, but I presume you're not doing that. You can however, send data back to the webserver through AJAX and have it store it for you.
You can create cookies to store data on the local machine, which pretty much is the only way to create files on the local machine.
I assume you have the content of the file ready. Then you can prompt a "save as" dialog like this:
var exportText; // this variable needs to contain your content
var targetFilename = "myfilename.ext"
function presentExportFile() {
var download = document.createElement('a');
// you need to change the contenttype to your needs in the next line.
download.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(exportText));
download.setAttribute('download', targetFilename);
download.style.display = 'none';
document.body.appendChild(download);
download.click();
document.body.removeChild(download);
}
2017 addendum: Since I wrote this, I had one exotic browser (xombrero) reject it. So, I can't say for certain that this is The Way.
no, this would be a security issue.
You can create a file through a plugin, see https://developer.mozilla.org/en/Code_snippets/File_I%2F%2FO
<html>
<head>
<title>Create File</title>
<! This function will create a file named 'newfile' on the same directory as the HTML unless path is given>
<script language="javascript">
function openFile()
{ var filePath = 'c:/filename.txt';
var fileSysObj = new ActiveXObject('Scripting.FileSystemObject');
fileSysObj.CreateTextFile(filePath);
}
</script>
</head>
<body>
This will create a file called "filename.txt" on your c:\ drive.
You must accept the ActiveX control or disable prompting to create a file.
<button type=submit name=button onClick="openFile();">create file</button>
</body>
</html>