I am relatively new to working with JSPs and I have a feeling I'm overlooking something simple. I have a segment that appends a key onto a URL before sending the user back to where they came from. The key is a string value and when it consists of only numberic values(for example 12345) it works fine, but when it contains non-numerics(for example abcde) it simply appends "#" to the url and stays on the same page.
<core:when test="${dataTransferObject.someBoolean}">
Back to Home
</core:when>
When it's a string the JavaScript will be illegal–it will think you're trying to reference a non-existent JavaScript variable. You will see an error your JavaScript console.
Don't do any JavaScript operations; JSP is evaluated on the server side before the client sees it:
onclick="javascript:location='path/back/to/their/home.request?cachekey=<core:out value="${dataTransferObject.stringVariable}"/>';return false;"
Better yet, use JSP EL:
onclick="javascript:location='path/back/to/their/home.request?cachekey=${dataTransferObject.stringVariable}';return false;"
Also, if this is the JSTL core tag library, the canonical prefix is "c".
Related
I'm using struts2 framework(java/js/html/css combo) for my webapp. I am reading a text file from server and I want to write the response to an iFrame present in the same jsp.
Flow:
(1) On click of a link, I pass the relative URL of the text file to jsp.
(2) When the jsp page loads, the java code in the jsp reads the file from server.
(3) Now this response has to be written to an iFrame present in the same jsp file
Can anyone plz help me in writing such response to an iFrame?
Thanks in advance :)
[code not tested, only a demostration of the concept]
here's some very rough idea as to how to fix your code, they definitly not the best but they should be enough to help you understand the concept.
However I'd still recommend going over the whole concept and maybe come up with a more efficent way to do what you need.
if you insist on using iframe, you need to make use of 2 seperate jsp as W3C says in "Implementing HTML Frames":
Any frame that attempts to assign as its SRC a URL used by any of its ancestors is treated as if it has no SRC URL at all (basically a blank frame).
so you'll need 2 jsp, the first one is basically what you have but the the src of the iframe changed to:
<iframe scrolling="yes" width="80%" height="200" src="second.jsp?content=<%=all%>" name="imgbox" id="imgbox">
and the second one will be something like :
<html><body><%= request.getAttribute("content") %></body></html>
From the code you've shown you forced a "content update" on the iframe by using javascript. The proper/usual way to update an iframe is to provide different input parameter to the second jsp and let it update it for you.
Finally, I'd recommend using JSTL as much as possible instead of scriptlets. It is much cleaner.
What you need to do is set the src attribute of the IFRAME to the jsp url when your link is clicked. Another way to do it is doing something like this:
<iframe src="" name="iframe_a"></iframe>
<p>W3Schools.com</p>
with the correct parameters of course
I am creating a user authentification in JSF2, and my header displayed on every page contains this:
<c:if test="#{user.loggedIn}">
<li><h:link value="Log out" outcome="#{user.logout}"/></li>
</c:if>
User refers to the userBean, and logout() simply invalidates the session, and issues a redirect to the login page. So when the user logs in, user.loggedIn becomes true, and logout link gets displayed, but it somehow immediately gets called, and the user is immediately logged out.
Does anyone have an idea why is this happening? I thought of using h:commandLink, but it requires a form, and I'm trying to avoid it.
Edit:
I copied the wrong code... just my luck after spending an hour figuring out why the user cannot login. You can look at the previous revision to see miscopied code.
That can happen when the JSF tags are not recognized and parsed as such and it effectively get rendered as plain text wherein all EL expressions are evaluated as value expressions. It would in your case basically print the returned value of #{user.logout()}. But while EL does that, the method's logic is of course invoked.
If you remove the action attribute and open the page in browser and do a View Source, then you'll see an unparsed <h:commandLink> tag instead of the generated HTML <a> element.
Make sure that you have the h: XML namespace definied on the right URI in the root tag of the view file.
xmlns:h="http://java.sun.com/jsf/html"
Update: the <h:link> isn't intented to invoke bean actions. It's intented as a pure GET link. The outcome is per specification evaluated as a value expression, not as a method expression. The outcome must represent a view ID where the link has to navigate to. When the EL evaluates your method as a value expression, it's of course immediately invoked. Just keep using <h:commandLink> in combination with a redirect. Additional advantage is that this isn't bookmarkable nor searchbot-crawlable.
This is the example from jsfToolbox:
<h:commandLink id="link1"
value="#{bundle.checkoutLabel}"
action="#{shoppingCartBean.checkout}" />
Get rid of your parens at the end of logout.
I m trying to access JavaScript function from Servlet code. But I'm getting the error shown below.
Here is the code:
out.println("<FRAME src=\"javascript:parent.newWindow('" + URL+ "') \" scrolling=No noresize />");
And this is the error that occurs in JavaScript:
Object does not support this property or method;
You can't access a Javascript function from your servlet code. Javascript executes on the client (= your user's browser) and the servlet code executes on your server (for example Tomcat, JBoss, whatever you're using).
What are you trying to accomplish with your code? I'm sure there's a simpler way to do it than what you just described.
[edited]
I see you just updated your description, so here's my view:
I'm guessing that you want to display a page to the user and when the page is displayed, you want to open a new window which will display another page using the URL parameter to point its address. If this is the case, you should probably just do this in the first page's onLoad() Javascript event using window.open().
There is no newWindow property on a window object (which is what parent references), so this is not unexpected.
Maybe you are looking for the open method instead?
If so, then:
Putting it as the src of an iframe is a very strange thing to do
It will probably be zapped by pop-up blockers
Ok. You try to generate javascript code inside Servlet code. When you do, your code goes to Web browser and it's seen there as a html document with javascript inside. So, your error rather comes from web browser and links to javascript error. Probably it's newWindow method. To open new window you should call window.open() function, I guess.
I'm using netbeans to create a web application that allows a cell phone user to scan a QR code and retrieve a journal's previous/next title information. The take home point is that there's no form that the user will input data into. The QR code will contain the search string at the end of the URL and I want the search to start on page load and output a page with the search results. For now (due to simplicity), my model is simply parsing an XML file of a small sample of MARC records. Oh, to top it off...I'm brand new to programming in java and using netbeans. I have no clue about what javabeans are, or any of the more advance techniques. So, with that background explanation here's my question.
I have created a java class (main method) that parses my xml and retrieves the results correctly. I have an index.jsp with my html in it. Within the index.jsp, I have no problem using get to get the title information from my URL. But I have no clue how I would get those parameters to a servlet that contains my java code. If I manage to get the search string to the servlet, then I have no idea how to send that data back to the index.jsp to display in the browser.
So far every example I've seen has assumed you're getting form data, but I need parameters found, processed and returned on page load...IOW, with no user input.
Thanks for any advice.
Ceci
Just put the necessary preprocessing code in doGet() method of the servlet:
String foo = request.getParameter("foo");
// ...
request.getRequestDispatcher("/WEB-INF/page.jsp").forward(request, response);
And call the URL of the servlet instead of the JSP one e.g. http://example.com/page?foo=bar instead of http://example.com/page.jsp?foo=bar in combination with a servlet mapping on an URL pattern of /page/*.
You can get the url parameter in servlet using request.getParameter("paramName");
and you can pass the attribute to page from servlet using forwarding request from servlet to jsp.
See Also
Servlet wiki page
Bear in mind that your JSP page will compile internally to a servlet. So you can retrieve the string and print it back in the same JSP. For instance assuming you get the string in a parameter called param you would have something like this in your JSP:
<%
String param = request.getParameter( "param" );
out.println( "String passed in was " + param );
%>
One last thing, you mentioned the main method -- that only gets executed for stand alone applications -- whereas you're talking web/JSP :O
why use<bean:include instead of <jsp:include in struts?
from the documentation for bean:include
Perform an internal dispatch to the specified application component (or external URL) and make the response data from that request available as a bean of type String. This tag has a function similar to that of the standard jsp:include tag, except that the response data is stored in a page scope attribute instead of being written to the output stream. If the current request is part of a session, the generated request for the include will also include the session identifier (and thus be part of the same session).
first hit on google
bean:include works almost like jsp:include except that the result is stored in the page scope. This means that your code on the current page can access the results and manipulate it. See this page.