Develop Reference

Android Calling JavaScript functions in Button

I've an Android Activity and I've got a Button that button need to access some Javascript function. Simply my app get the user info(ID,pass) then go to web page(this operation doing backgrun with asynctask class) write these two info as ID and pass then user click the Log In button in my app button has to use some js function
<script type="text/javascript">
//<![CDATA[
var theForm = document.forms['form1'];
if (!theForm) {
theForm = document.form1;
}
function __doPostBack(eventTarget, eventArgument) {
if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
theForm.__EVENTTARGET.value = eventTarget;
theForm.__EVENTARGUMENT.value = eventArgument;
theForm.submit();
}
}
//]]>
</script>
this is the func. i need to use
My post and get request for connection the site are
POST//
URL url = new URL(params[0]); //http://login.cu.edu.tr/Login.aspx? site=https://derskayit.cu.edu.tr&ReturnUrl=%2f
connection=(HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream());
writer.write(data);
writer.flush();
these codes for the put the ID and pass
GET //
reader= new BufferedReader((new InputStreamReader(connection.getInputStream())));
StringBuilder builder = new StringBuilder();
String line;
while((line= reader.readLine())!=null){
builder.append(line + "\n");
}
text=builder.toString();
there is any help or suggestion for me i am very confused about that situation and i feel really bad myself thanks for helps anyway. Have a nice day

For using Javascript without a webView to make requests!
The question has already an answer here in this question
The javax.script package is not part of the Android SDK. You can execute JavaScript in a WebView, as described here. You perhaps can use Rhino, as described here. You might also take a look at the Scripting Layer for Android project.
Also a similar question was asked here
You can execute JavaScript without a WebView. You can use AndroidJSCore. Here is a quick example how you might do it:
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://your_website_here/file.js");
HttpResponse response = client.execute(request);
String js = EntityUtils.toString(response.getEntity());
JSContext context = new JSContext();
context.evaluateScript(js);
context.evaluateScript("question.vote(0);");
However, this most likely won't work outside of a WebView, because I presume you are not only relying on JavaScript, but AJAX, which is not part of pure JavaScript. It requires a browser implementation.
Is there a reason you don't use a hidden WebView and simply inject your code?
// Create a WebView and load a page that includes your JS file
webView.evaluateJavascript("question.vote(0);", null);
Otherwise:
Yes you can make HTTP POST and HTTP GET requests without using WebView. But if you want to use a webView remember Javascript in a webview is disabled by default (for security purposes). So before calling any javascript functions make sure you enable javascript in your webview like this
webView.getSettings().setJavaScriptEnabled( true );
And after that javascript will be enabled in your webView.
But in case you do not want to use a webview and javascript to make http requests. There is a lot of alternative methods you can define a Button in your activity's layout in xml. And respond with a http request on button Clicked listener!
Also remember making http Request using Android/Java default classes is a huge task and error prone and requires you to care about using async tasks to avoid blocking the UI thread.
Alternatively
In android we use ready-made library to make http requests. Google has a good library called Volley. it is easy to customize,respond to errors and it automatically making request out of the main thread.See more explanation here!. If there is still some problems comment below!

Googlebots causes JS errors, should I care?

On production server, I watch JS errors and send to the server:
<script type="text/javascript">
window.onerror=function(msg,url,line) {
if (window.XMLHttpRequest)
{
var xmlhttp = new XMLHttpRequest();
}
else
{
var xmlhttp = new ActiveXObject('Microsoft.XMLHTTP');
}
xmlhttp.open('POST', '/logJSerrorsHere', true);
xmlhttp.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
xmlhttp.send('msg='+encodeURIComponent(msg)+'&url='+encodeURIComponent(url)+'&line='+line);
return true;
}</script>
and sometimes it logs some "mysterious" errors: "$ is not defined", but all of them comes from "googlebot(at)googlebot.com" or spiderbot. Should I deal with it?

Depends :) If your site is readable and indexable with out Javascript (and your site is visible in search) I wouldn't worry too much about it, unless you feel the error is indicative of a bigger issue. You can test this using Fetch and Render in Google Webmaster Tools.
If your site relies on Javascript to render the page (i.e. it uses AngularJS for example) then yes, fix it.

Uncaught TypeError: Object #<Document> has no method 'load'

guys,im having trouble reading xml files using javascript, plz help me
here is my code:
<html>
<body>
<script type="text/javascript">
var xmlDoc=document.implementation.createDocument("","",null);
xmlDoc.load("myfile.xml");
</script>
</body>
</html>
im using win7 ,I've used opera 12,the latest chorme, firefox 14,IE9,safari 5(windows verison),and none of them works, and google chorme gives me this
Uncaught TypeError: Object #<Document> has no method 'load'
i dont know whats wrong here, thx in advance

guys,im having trouble reading xml files using javascript
Lots of google results for loading xml files dynamically using javascript (cf. AJAX). But to help you get started in the right direction, consider
// Caveat: IE 5 and IE 6 must do:
// var xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("GET","myfile.xml",false); // the third param sets async=false
xmlhttp.send();
var xmldata = xmlhttp.responseXML;
EDIT: the above was from my AJAX notes, see the w3 tutorial on the topic for the walk-through version.

XDomainRequest - not calling...not doing anything

I've a problem...I use jQuery ajax to call a web service that returns XML. The jQuery ajax stuff works awesome for every browser except for ie.
So for ie browsers, I am using XDomainRequest. Here is the code:
if ($.browser.msie && window.XDomainRequest) {
// Use Microsoft XDR
var xdr = new XDomainRequest();
xdr.open("get", theUserUrl);
xdr.timeout = 95000;
xdr.onerror = function () {
console.log('we have an error!');
}
xdr.onprogress = function () {
console.log('this sucks!');
};
xdr.ontimeout = function () {
console.log('it timed out!');
};
xdr.onopen = function () {
console.log('we open the xdomainrequest');
};
xdr.onload = function () {
// XDomainRequest doesn't provide responseXml, so if you need it:
var xml2 = new ActiveXObject("Microsoft.XMLDOM");
xml2.async = false;
xml2.loadXML(xdr.responseText);
console.log('do we get any response text at all?: ' + xdr.responseText);
ParseOwnershipObjects(xml2);
//AddServiceRequestsToMap(xml2, map, spinner);
};
xdr.send();
}
This exact code works fine elsewhere in the application with a
different url.
The url is fine, it returns exactly what it should in the browser
(and hence why the jquery ajax call works). Couple of things to
note:
I am integrating my own html/javascript with another guy's asp.net
project.
In the global.asax.cs file, I have:
protected void Application_BeginRequest(object sender, EventArgs e)
{
HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "*");
HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "GET,OPTIONS");
}
so I don't think that it's a header problem.
None of my handlers fire. Not the onprogress, ontimeout, onerror...nothing!
I don't have time to convert the web service to JSON.
Any thoughts?
Thanks!

Disclaimer - I actually haven't used 'XDomainRequest' - when using jQ I set data to jsonp for xdomain requests...
When debugging - are you using IE Dev tools (F12)? If not, the error is likely console.log
EDIT:
mea culpa, disregard the jsonp stuff - missed the part you mentioned XML
Update:
Out of curiosity I'm trying XDomainRequest. I copied your code and just added a value for theUserUrl.
as above/expected, unless I have Internet Explorer Developer tools running, console is undefined - and may give the impression that "none of your handlers are firing".
Once I have the IE dev tools enabled (docked or otherwise) xdr.onerror fires. we have an error is logged in the IE console. So while there is an error, the handler does fire.
A quick read on XDomainRequest requires the responding server to have the Access-Control-Allow-Origin header. I'm calling my own server and I know I don't have this header set, so without further debugging, it would be a good guess that's why xdr.onerror is being fired.

As it turns out, there were special characters in the url parameters that were not being correctly dealt with by the XDomainRequest object. Instead of the GET request, I am going to use the POST request on internet explorer-only queries.
EDIT - I ended up switching the web service over to return output in JSON format, thus negating the need for the XDomainRequest. Using JSON speeds things up a bit too, I recommend it!

Porting Issue - Internet Explorer to Everything Else

I have some code which was developed on a Windows 7 computer and runs any Windows 7 compeer without any hiccups. I tried running it on my Mac and the program just stays on the loading page.
The program displays the bing maps view and loads a few things in order to get the location of a particular satellite. Now all the maths and stuff works but I think the problem lies here:
function getOrbitalElements()
{
TLE_Line1="";
TLE_Line2="";
pgTXT = "";
xmlhttp = null;
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
if (xmlhttp!=null)
{
xmlhttp.onreadystatechange = stateChange;
xmlhttp.open("GET",url,true);
xmlhttp.send(null);
}
}
So is there any way that this can be changed to run on any browser? Thanks
P.S. If you need to see the entire code I'll add it

There are no ActiveX objects on Mac. The following line won't work:
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
You could use XMLHttpRequest:
var xmlhttp = null;
if (window.XMLHttpRequest) { // Mozilla, Safari, ...
xmlhttp = new XMLHttpRequest();
} else if (window.ActiveXObject) { // IE 8 and older
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
if (xmlhttp != null) {
...
}
But if you are seeking best cross browser support I would recommend you using a javascript framework such as jQuery to perform your AJAX requests.

Replace
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
with
xmlhttp = window.ActiveXObject?new ActiveXObject("Microsoft.XMLHTTP"):new XMLHttpRequest();
EDIT
As others have said, you might find benefit in using something like jQuery (which is very good) but you may not need to take the effort to adjust your existing code just yet. If you have written good (standards) javascript, you will find the browser cross-compatibility issues should be minimal.
In the future, be sure to test in other browsers early and often to avoid this kind of problem.

The best way to port a particular web app from a Browser specific version to a browser agnostic one is to use a javascript framework like jQuery. It's designed to smooth out the rough edges that come up between different browsers into a friendly + unified API. For example the above code could be done across multiple browsers with a jQuery ajax request
$.ajax({
url: url,
success: function () {
// Called when the query completes
statechange();
}});