I use this script (from dynamicdrive) to dynamically fill div with id:
var bustcachevar=1 //bust potential caching of external pages after initial request? (1=yes, 0=no)
var loadedobjects=""
var rootdomain="http://"+window.location.hostname
var bustcacheparameter=""
function ajaxpage(url, containerid){
var page_request = false
if (window.XMLHttpRequest) // if Mozilla, Safari etc
page_request = new XMLHttpRequest();
else if (window.ActiveXObject){ // if IE
try {
page_request = new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e){
try{
page_request = new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e){}
}
}
else
return false
page_request.onreadystatechange=function(){
loadpage(page_request, containerid)
}
if (bustcachevar) //if bust caching of external page
bustcacheparameter=(url.indexOf("?")!=-1)? "&"+new Date().getTime() : "?"+new Date().getTime()
page_request.open('GET', url+bustcacheparameter, true)
page_request.send(null)
}
function loadpage(page_request, containerid){
if (page_request.readyState == 4 && (page_request.status==200 || window.location.href.indexOf("http")==-1))
document.getElementById(containerid).innerHTML=page_request.responseText
}
Everything works fine until I load a page with for example a euro-sign in it.
Codepage's are set correctly on the page but it displays a questionmark.
I don't know enough javascript to fix this problem.
Thanks in advance for any advice!
NOTE: Thanks to friend I now know that saving the file you want to load using this script in UTF-8 fixes the problem. But I can't be sure that every page I load is UTF-8 encoded so my question is:
is there a way for the script to set the right charset? Is there a way to let the script adapt to the codepage of the file you want to load?
It seems like you have an encoding problem somewhere.
I highly suggest you to use UTF-8 everywhere as it is the established standard for the web. Check that the page doing the ajax call and the dynamically loaded page are encoded in UTF-8 and sent by the server with correct headers (the headers should contain something like Content-type: text/html; charset=UTF-8).
Also it is a best practice to replace exotic characters by their html firendly code in html pages to avoid such issues. Use € for €.
This is my hypothesis (and I think it's been confirmed by your updates):
When you write the remote document you are loading, you just open your editor, hit the € symbol in your keyboard and save. Since you never picked any encoding, your editor used the ANSI code page. And here's the issue: the ANSI code page basically depends on where you live. In Western Europe, Win-1252 is a popular choice and encodes the euro symbol as 0x80.
When you write the target HTML doc where you want to insert it, you do exactly the same and get a Win-1252 document. However, the webserver doesn't know what the encoding is. Many times, it'll default to something like ISO-8859-1 and it happens that ISO-8859-1 does not even have an euro symbol!
JavaScript reads 0x80 and writes 0x80.
The browser finds 0x80 in an HTML document that's supposedly ISO-8859-1. In such encoding, the 0x80 is actually blank.
So you don't have to fix your JavaScript code (there's nothing fixable there, mainly because there's nothing wrong there). You need to find out what your site's encoding is and generate files that actually use such encoding (advanced editors will let you choose).
Related
I have a short HTML file that tries to add a one-line footer that will be common to several files by using w3IncludeHTML. Some of the time, it works, but some of the time the last bit of HTML before the call to w3IncludeHTML is replaced by the footer, with the end result being that the last bit is missing and the footer appears twice.
Here's my calling page:
<head>
<script src="http://www.w3schools.com/lib/w3data.js"></script>
</head>
<body>
« Previous • Home
<div w3-include-html="Footer.html"></div>
<script>
w3IncludeHTML();
</script>
</body>
Here's my footer page:
Footer.
When it works, my output looks like this:
« Previous • Home
Footer.
When it doesn't work, it looks like this:
« Previous •
Footer.
Footer.
There is no way I have found to force either behavior. Whether it works or not appears to be at random, with the error coming and going as I refresh the page over and over.
I'm using Chrome 53.0.2785.143 m and running Apache HTTP Server 2.4.7 as my localhost under Windows 10 Version 1607 Build 14393.321. (Problem may well be a Chrome issue, as IE11, FireFox 49, and Edge don't show the same behavior.)
Can anyone help me understand why this is happening? Thanks!
UPDATE:
I pulled out the JavaScript function's source and played with that a bit. The problem goes away if, at the point where the function opens an XMLHttpRequest, it asks for the subsequent send operation to be synchronous. This doesn't appear to be a real fix, though, as synchronous use of send is deprecated on the main thread. I'm no JavaScript guru, so I'm don't understand why making this operation asynchronous would cause the problem I am seeing. Is it a bug in Chrome, maybe?
Here's the JavaScript (please note I have changed the name of the function and the name of the attribute it looks for, and reformatted it a bit; other than that, it is that same as w3schools' version, but for the change from true to false in the call to the open method):
function xLuIncludeFile()
{
var z, i, a, file, xhttp;
z = document.getElementsByTagName("*");
for (i = 0; i < z.length; i++)
{
if (z[i].getAttribute("xlu-include-file"))
{
a = z[i].cloneNode(false);
file = z[i].getAttribute("xlu-include-file");
xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function()
{
if (xhttp.readyState == 4 && xhttp.status == 200)
{
a.removeAttribute("xlu-include-file");
a.innerHTML = xhttp.responseText;
z[i].parentNode.replaceChild(a, z[i]);
xLuIncludeFile();
}
}
// false makes the send operation synchronous, which solves a problem
// when using this function in short pages with Chrome. But it is
// deprecated on the main thread due to its impact on responsiveness.
// This call may end up throwing an exception someday.
xhttp.open("GET", file, false);
xhttp.send();
return;
}
}
}
The problem is caused by installing and enabling the "Chrome Stylist" extension, version 2.1.0. Disabling that extension makes the problem go away.
I am trying to get text from a service on the same server as my webserver. The link is something like this:
http://<OwnIPadres>:8080/calc/something?var=that
This is my code:
function httpGet(theUrl)
{
alert(theUrl);
var doc = new XMLHttpRequest();
doc.onreadystatechange = function() {
if (doc.readyState == XMLHttpRequest.DONE) {
alert("text: " + doc.responseText );
document.getElementById('ctm').text = doc.responseText;
}
}
doc.open("get", theUrl);
doc.setRequestHeader("Content-Encoding", "UTF-8");
doc.send();
}
The url that i print in my first alert is the good one if i test in my browser, it is an html page with a table in it. But the alert of my text is empty? Is it a problem that the text is html?
Actually, its quite ok that your 'text' is 'html'. The problem is that using a different port counts as cross-site scripting. Therefore, your XMLHttpRequest is being stopped by the browser before it actually reaches your page across port 8080.
I'm not sure what else you're doing before and around this code snippet, but you could try an iframe call to your url to get your data, or you could add an
Access-Control-Allow-Origin: http://:8080/
in your header (however that will only get you the most modern browsers).
Finally, you could pull in a JS framework like JQuery which could help you with pulling in this service data.
I am trying to learn how to read into a web page data in an XML file. This is a static HTML page. I do not want a web server and I cannot use Ajax. The XML file is local (in the same directory as the HTML file). I want this to work in a Chrome browser.
What I need to do is:
Read the XML file on the page onLoad event.
Use innerHTML to insert the XML data into a div.
My problem is in reading the XML file. All of the examples I have found I think will only work if there is a web server running, which I have to avoid.
If you're reading another file the only way to do that with front end JS is another request (ajax). If this were node.js it would be different because node can access the filesystem. Alternatively if you get the xml into a javascript string on the same page, you can manipulate it. There are a number of good libraries (jquery's parseXML).
Original answer here: https://stackoverflow.com/a/48633464/8612509
So, I might be a little late to the party, but this is to help anybody else who's been ripping his/her hair out looking for a solution to this.
First of all, CORS needs to be allowed in the browser if you're not running your HTML file off a server. Second, I found that the code snippets most people refer to in these kind of threads don't work for loading local XML-files. Try this (example taken from the official docs):
var xhr = new XMLHttpRequest();
xhr.open('GET', 'file.xml', true);
xhr.timeout = 2000; // time in milliseconds
xhr.onload = function () {
// Request finished. Do processing here.
var xmlDoc = this.responseXML; // <- Here's your XML file
};
xhr.ontimeout = function (e) {
// XMLHttpRequest timed out. Do something here.
};
xhr.send(null);
The method (1st arg) is ignored in xhr.open if you're referring to a local file, and async (3rd arg) is true by default, so you really just need to point to your file and then parse the result! =)
Good luck!
Since you're only targeting Chrome, you could take a look at the File API. You'd have to prompt the user to select the file or drop it into a specific area of the page though, which might be something you'd rather avoid, or not. The following HTML5 Rocks article should help.
Assuming the HTML, XML and browser are all on the same machine, you might try using an Iframe in the HTML that references the XML using a URL like file:\.
You could do something like this:
<html>
<head>
<script type="text/javascript">
//If using jQuery, select the tag using something like this to manipulate
//the look of the xml tags and stuff.
$('#xframe').attr('style', 'thisxmltag.....');
</script>
</head>
<body>
...
<frame id="xframe" src="the_xml_doc"></src>
</body>
</html>
if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp = new XMLHttpRequest();
}
else {// code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.open("GET", file_Location, false);
xmlhttp.send();
xmlDoc = xmlhttp.responseXML;
document.getElementById(your_div_id).value =
xmlDoc.getElementsByTagName(The_tag_in_xml_you_want_to_display)
[0].childNodes[0].nodeValue;
Works with IE11
<head>
// To be hidden with a better method than using width and height
<OBJECT id="data1" data="data.xml" width="1px" height="1px"></OBJECT>
// to work offline
<script src="lib/jquery-2.2.3.min.js"></script>
</head>
<body>
<script>
var TheDocument = document.getElementById("data1").contentDocument;
var Customers = TheDocument.getElementsByTagName("myListofCustomers");
var val1 = Customers[0].getElementsByTagName("Name")[0].childNodes[0].nodeValue;
I have a html page using javascript that gives the user the option to read and use his own text files from his PC. But I want to have an example file on the server that the user can open via a click on a button.
I have no idea what is the best way to open a server file. I googled a bit. (I'm new to html and javascript, so maybe my understanding of the following is incorrect!). I found that javascript is client based and it is not very straightforward to open a server file. It looks like it is easiest to use an iframe (?).
So I'm trying (first test is simply to open it onload of the webpage) the following. With kgr.bss on the same directory on the server as my html page:
<IFRAME SRC="kgr.bss" ID="myframe" onLoad="readFile();"> </IFRAME>
and (with file_inhoud, lines defined elsewhere)
function readFile() {
func="readFile=";
debug2("0");
var x=document.getElementById("myframe");
debug2("1");
var doc = x.contentDocument ? x.contentDocument : (x.contentWindow.document || x.document);
debug2("1a"+doc);
var file_inhoud=doc.document.body;
debug2("2:");
lines = file_inhoud.split("\n");
debug2("3");
fileloaded();
debug2("4");
}
Debug function shows:
readFile=0//readFile=1//readFile=1a[object HTMLDocument]//
So statement that stops the program is:
var file_inhoud=doc.document.body;
What is wrong? What is correct (or best) way to read this file?
Note: I see that the file is read and displayed in the frame.
Thanks!
Your best bet, since the file is on your server is to retrieve it via "ajax". This stands for Asynchronous JavaScript And XML, but the XML part is completely optional, it can be used with all sorts of content types (including plain text). (For that matter, the asynchronous part is optional as well, but it's best to stick with that.)
Here's a basic example of requesting text file data using ajax:
function getFileFromServer(url, doneCallback) {
var xhr;
xhr = new XMLHttpRequest();
xhr.onreadystatechange = handleStateChange;
xhr.open("GET", url, true);
xhr.send();
function handleStateChange() {
if (xhr.readyState === 4) {
doneCallback(xhr.status == 200 ? xhr.responseText : null);
}
}
}
You'd call that like this:
getFileFromServer("path/to/file", function(text) {
if (text === null) {
// An error occurred
}
else {
// `text` is the file text
}
});
However, the above is somewhat simplified. It would work with modern browsers, but not some older ones, where you have to work around some issues.
Update: You said in a comment below that you're using jQuery. If so, you can use its ajax function and get the benefit of jQuery's workarounds for some browser inconsistencies:
$.ajax({
type: "GET",
url: "path/to/file",
success: function(text) {
// `text` is the file text
},
error: function() {
// An error occurred
}
});
Side note:
I found that javascript is client based...
No. This is a myth. JavaScript is just a programming language. It can be used in browsers, on servers, on your workstation, etc. In fact, JavaScript was originally developed for server-side use.
These days, the most common use (and your use-case) is indeed in web browsers, client-side, but JavaScript is not limited to the client in the general case. And it's having a major resurgence on the server and elsewhere, in fact.
The usual way to retrieve a text file (or any other server side resource) is to use AJAX. Here is an example of how you could alert the contents of a text file:
var xhr;
if (window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
} else if (window.ActiveXObject) {
xhr = new ActiveXObject("Microsoft.XMLHTTP");
}
xhr.onreadystatechange = function(){alert(xhr.responseText);};
xhr.open("GET","kgr.bss"); //assuming kgr.bss is plaintext
xhr.send();
The problem with your ultimate goal however is that it has traditionally not been possible to use javascript to access the client file system. However, the new HTML5 file API is changing this. You can read up on it here.
A slew of pages I've written for one of my web projects share some 144 identical lines of code, reproduced in each file. If I update one of those lines, I have to go back through ALL of the pages that share the code and update for each page. Is there a straightforward way to include HTML from a separate file?
And for bonus points, since so many pages use this code, it would be nice not to have to reload it for each page. Is there an easy way to store it in the browser's cache or only load the "content" section of the pages while leaving the rest of the page static?
Fountains of Thanks for any wisdom on this.
Mike
To include HTML from a separate file, use SSI (Server-Side Includes). This requires SSI support to be installed on the server, however.
You would write something like this in your files:
<!--#include file="included.html" -->
and that would include the file included.html when the page is accessed.
To load only the content of each page, use the XMLHTTPRequest object from JavaScript:
function LoadContent(url)
{
if (typeof(XMLHttpRequest) == "undefined")
{
try
{
xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
}
catch(e)
{
try
{
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e)
{
// fallback for browsers without XMLHttpRequest
window.location.href = "no-ajax.php?url="+escape(url);
return;
}
}
}
else
{
xmlhttp = new XMLHttpRequest();
}
xmlhttp.open("GET", url, false); // this request will be synchronous (will pause the script)
xmlhttp.send();
if(xmlhttp.status > 399) // 1xx, 2xx and 3xx status codes are not errors
{
// put error handling here
}
document.getElementById("content").innerHTML = xmlhttp.responseText;
}
If we're assuming that you're talking straight html pages, with no server code (asp.net, php, or server side include ability), then in order to do both the including and the caching, you're going to need to use an iframe.
Each of your pages that duplicate the 144 lines of content should replace it with an iframe like so:
<iframe src="pagewithcontent.html"></iframe>
pagewithcontent.html would obviously be where you move the content to. The browser will cache the page appropriately, so that each parent page will simply get the shared content without making another request.
There's an article here that goes into great depth about html includes, and some javascript methods of doing it. I would strongly recommend against the javascript methods.
My answer reflects the assumption that you can't do anything on the server side. However, by far the best solution is to do so if you can.