can ajax call other ajax page? - java

I have index page,which contain div section.i want to call different pages into this div section on the basis of her-link click,this is done. when calling pages that may also using ajax call,in this case ajax call not work for this page.please tell me it is possible to call ajax inside an ajax.if yes then please help me.
Update Edit:
I have created a gist where i have include all used pages,script https://gist.github.com/2786811.page service_status called the view.jsp using ajax call every 5 second,on hand view.jsp interact with database and prepare view.when we do ajax call from index.jsp, service_status called but it doesn't called view.jsp file.
Thanks

You can make ajax call on page load using $(document).ready(function () {...}); in target page you are calling.

If you are trying to dump a <script> tag with innerHTML, it won't work.
However, you could (as an example) return a JSON object with two properties:
{
html: "All your <b>HTML</b> here",
js: "alert('JavaScript to be run');"
}
Then, use the html property to put content on the page, and then eval the js property.
This isn't the best solution, since it uses the evil eval, but unless you want to rewrite your whole basic structure to use callbacks properly then it's probably your best bet.

Related

Calling part of jsp page from Servlet or Java Class

I need to call small part of JSP page(like only div load) when a method is invoked? I know we can load whole JSP page from Servlet. Is this possible or any other solution for this?
know we can load whole JSP page from Servlet. Is this possible
Yes it is possible, you forward your request to jsp from servlet and it will render that jsp, here is an exact same example
1) Set some session or request variable equal to some value, say boolean myVar = true.
2) Redirect from your jsp page from your servlet.
3) In the jsp page, check for particular condition for the variable myVar. If condition is fulfilled, using scriptlets or JSTL display only the relevant part of you jsp.
You can use AJAX(Asynchronous Javascript and XML) for this purpose
For example, Suggestions, that appear without any refresh for auto-complete in google search, are using Ajax. JSP code will contain the Ajax code and will send the information to the servlet in form of XmlHttpRequest object and then takes the response from servlet as xmlhttp.responseText. The result can be written at JSP page by using DOM.
To initiate this process, you need to use the onkeyup in input tag like this:
<input type="text" onkeyup="methodName(this.value)"
Learn more about Ajax
To use AJAX with Java, try this
Ajax for Java Web Applications
$('#myDiv').load('serverPage.jsp #server_div_id');
OR
$.ajax({
url: 'serverPage.jsp',
success: function(data) {
data=$(data).find('div#id');
$('#mydiv').html(data);
}
});

How do I inject another JSP page into a <div> when clicking a link?

I have two different divisions in a JSP page. One contains a menu of links, when clicked the div2 (id-content) loads different pages accordingly. I am doing something like -
<div id="menu">
<ul class="navbar">
<li><a name="login" href="Login.jsp" onclick="changeContent()">Login</a>
</li></div>
and in the script I have something as -
<script language="JavaScript">
function changeContent() {
document.getElementById('content').load('Login.jsp');
}
</script>
I also tried -
document.getElementById('content').innerHTML=
"<jsp:include page="Login.jsp">";
None of the ways worked. Please suggest how should I
Try jquery..
function changeContent() {
$('#content').load('Login.jsp');
}
The solution is to use Ajax, which will asynchronously retrieve your page content that can be pasted in with the innerHTML method. See my answer to a similar question of how an Ajax call works and some introductory links.
As to why your examples in your answer don't work, in the first case there is no load() method on an Element object (unless you've defined one yourself and not shown it). In the second example, as one of the question comments says, there is probably something causing a syntax error in the javascript.
As an FYI, when there is a syntax error in some javascript in a web page, the current expression being parsed and the rest of the <script></script> block will be ignored. Since this is inside a function declaration, that function will never get defined.
For instance, an embedded quote in the included page will end the string for the innerHTML assignment. Then the javascript parser will try to parse the remainder of the HTML causing a syntax error as the HTML will not be valid javascript.
We use jquery. Add a click event handler to the anchor elements. In the click handler call $('#content').load(your_url);. You might want to use the load(url, function() { ...}) version. More info here http://api.jquery.com/load/
Your initial page comes down from the server. It's displayed by the browser. When you click on a link (or a button) in the browser, you want to fill the second div with new HTML. This is is a perfect job for an AJAX request. What the AJAX object in the browser does, is to send a POST (or whatever) string to the server. And then the Ajax object receives the HTML response back from the server. And then you can display that response data which the AJAX object contains, anywhere you want.

Communicating between JavaScript and Servlet

In my JSP page I have DIV.
<div id="100">
ALI
</div>
When I click on this DIV...
$("#100").click(function(){
});
...I need to send the value of the id 100, to a servlet, so that the servlet makes some database java codes, and returns for example, either 1 or 0. How can I do that? and is this the proper way?
Using Ajax, you should call your server using a URL similar to this:
http://localhot:8080/youAppContext/yourServer?id=100
Then, in the servler side, you should retrieve the value that will be in the request with the name "id"
There are out there many tool as jQuery that can help you to do the Ajax petition.
Edited
Well, here you can find a very simple Ajax example using jQuery. In the example, instead call a file (test1.txt) you should invoke a URL (as I described above). Of course, you will need to write some JS code to build your URL (where id be a variable). Once task is done in servlet side, you can return whatever, for example: "done" and display or not this information the HTML as it is done in the example.
Take a look to this Web, there are many links that can help you.
get the value using
var value = $("#100").html();
and pass it to servlet using AJAX

How to generate success alerts in jsp after successful execution of a servlet?

I have a jsp page which contains a form which calls a servlet, after inserting data into the database by a servlet hot to display successs alert to the user on the page?
Thanks in advance for answering.
Either you call the servlet asynchronously with AJAX and have a success callback function (see jQuery example: http://api.jquery.com/category/ajax/ )
Or you do it the old fashioned way with a synchronous Post which loads a success page, or the same page with for example a query parameter that states that you have succeed. This could then be used to activate a script block in your JSP (or whatever template language is your flavour).
You can use a javascript alert box. See http://www.w3schools.com/js/js_popup.asp

how to show "data loading" in a jsp page using servlets

we have a classic JSP + Servlets application and would like to show "Content is loading" sort of message when data in the page takes a while to load.
Is there an easy way to do this via JS?
Scenario:
Page1 (a.jsp) -> select drop downs ->
click search //data is sent back to
server for db
URL changes to (b.jsp), white page is shown, then data load after 30ish seconds
for those 30 seconds I want to show a spinner or some message.
adding ajax or jquery would require a design change which we can not do right now. Though the application already uses jQuery for other stuff but b.jsp is making the DB call from that page...
calling DB in jsp would be very much frowned upon. given the premise of the question, you could
//b.jsp
<div id="msg">data is loading...</div>
<%
out.flush();
db.performanLengthJob();
%>
<script> $("msg").remove(); </script>
<p>Data is loaded!</p>
AJAX is the way to do it. You'll need something on the server side to help you keep track of progress.
Load your data (in b.jsp) with ajax request.
Make a JS function which starts on load, let it show your message ('30 seconds left') and then let it perform ajax request to load necessary data.
I recommend you to use some js-framework, like jQuery, it'll make things much simplier.
In order to handle ajax-request on the server-side you'll need to create one more servlet and map it to some url, like your_app_name/ajaxsupport. This servlet should return data in some convenient format (it can be plain text, or xml, or JSON or whatever else). On the client you'll process received data and show it.
A quick solution can be to use onbeforeunload JS event of your base page html body s.g. like
<body onbeforeunload="$("yourComponent").show();">

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