<s:set name="Name" value="%{'Gyan'}" />
<s:if test="%{#Name=='Singh'}">You Working with--
<div><s:property value="%{#Name}" /></div>
<div>Your Name is Gyan</div>
</s:if>
can any body tell me that what is the role of % and # symbol in above code ?
These are the various way to access dats being places by Struts2 in the value stack as well in other scope.
% is way to access or tell Struts2 that you want to resolve this particular expression against the value stored in the Value-stack, this is a way to force OGNL, a build in data-conversion and transfer mechanism to come to play.
To access the attributes values stored in Session, Application scope etc we use # which is an indicator to Struts2 that from where we want to access the values.
I suggest you to please refer official OGNL documents for more and clear details about this.
OGNL-Basics.
OGNL
Related
I'm am still pretty new to struts and am having trouble trying to compare two struts params in a struts if statement. I am trying find if the current year param is equal to the checkYear param
If they are equal I want to execute some code. If they are not equal then I would like to execute some other code..
Sample code:
<s:param name="currentYear">
<s:date name="%{new java.util.Date()}" format="yyyy" />
</s:param>
<s:param name="checkYear">
<s:date format="yyyy" name="#year"/>
</s:param>
<s:if test="${checkYear == legendYear}">
code executed
</s:if>
I don't really understand the purpose of the '$','%', or '{}' in the test part of the if statement if or how I need to apply it to have it check the params.
Thank you in advance!
Inside Struts2 tags, you use OGNL. Refer to the small language guide to see how it works.
In OGNL, %{} means you want to force the evaluation of an expression; it is needed somewhere, while it is superfluos somewhere else. In the <s:if/>, it is not needed, because test="" will evaluate its content by default.
${} does not exists in OGNL, it is JSP EL. Search on StackOverflow for some nice answer on that if you are curious.
{} alone in OGNL is List Projection... you probably don't need it now.
In my .jsp page I have
<s:url id="ecu" value="ecu-info-detail">
<s:param name="id" value="%{id}"></s:param>
<s:param name="ecuName" value="name"></s:param>
<s:param name="ajax" value="true"></s:param>
</s:url>
which I use in a sj:a tag thus;
<li class="vMenuItem"><sj:a href="%{ecu}" requestType="GET" targets="detail"><s:property value="description"/></sj:a></li>
when this link is clicked the url generated is in the format;
my.domain.com?id="01"&ecuName="foo"&ajax="true"
so the parameters ecuName and ajax do not get set on the action. Now I can get around this by simply adding the attribute escapeAmp="true" to the s:url definition. However, because the Struts 2 default is to escape the ampersand and because I cannot be the only person using multiple s:param tags, I am concerned that escapeAmp="true" may not be the correct way of handling this situation and I'm creating a security hole.
Is this the correct way to deal with this situation, and if not, how should I deal with it?
Regards
Posting answer as per the discussion in the comment section.Same issue was reported in the plugin development team url paramerters escaped.
Same issue was closed with a discussion that we need to escape that html in order for this to work with Jquery tags.For more details please read the filed bug ticket.
I'm struggling with a Struts2 date formatting issue. If I understand correctly, type conversion in Struts2 is locale aware, and any form fields/parameters that map to Date objects should be strings formatted in their Locale specific SHORT format; the default output for a Date object on the value stack is also output as the Locale specific SHORT format (unless overridden with custom formatting).
Although form fields have worked fine with dates, when using the <s:url> tag I can't seem to get the <s:param> tag to encode date parameters correctly. When I try something such as this
<s:url action="foo" >
<s:param name="endDateParam" value="#endDate"/>
</s:url>
the result is pretty obviously not the SHORT format:
/foo.action?endDateParam=Sat+Jan+14+00%3A00%3A00+EST+2012
I re-read the Struts2 documentation but they mostly discuss creating custom date formats in the i18n'ized properties files, which doesn't seem like the right solution.
Any help with this problem would be greatly appreciated.
You can send it like that :
<s:param name="dateFrom">
<s:date name="dateFrom" format="dd.MM.yyyy"/>
</s:param>
You've probably already solved this by formatting a string in the action the way you need it. This I would advise first, unless you are supper stickler for model/view separation or there isn't a one to one mapping between the action and the view in which case this zealousness my be justified.
Lets say you felt the formatting wasn't the business of the action in that case you could use OGNL to it's full effect:
Here is an example that displays the current date (it uses new to construct a new date but you can very easily just replace "new java.util.Date()" with "endDate". It was constructed this way so anyone can just paste it into their JSP without any action dependencies.
<p>
<s:property value="#java.text.DateFormat#getDateInstance(#java.text.DateFormat#SHORT, #java.util.Locale#CANADA).format(new java.util.Date())"/>
</p>
NOTE: requires OGNL static method access to be true. Easiest way to do that is to add the following to struts.xml:
<constant name="struts.ognl.allowStaticMethodAccess" value="true"/>
Using OGNL to this level is a bit suspicious but it is easy to read and the intention is clearly view/presentation related. Although it isn't that easy to construct... The easiest way is to write everything as one line of java and then apply ognl syntax rules which you would find here:
http://commons.apache.org/ognl/language-guide.html
Also for quick reference:
http://docs.oracle.com/javase/7/docs/api/java/text/DateFormat.html
http://docs.oracle.com/javase/7/docs/api/java/util/Locale.html
What is the reason to use g:textField in Grails if you're already familiar with standard HTML form tags?
If I understand correctly the following two markup alternatives are equivalent:
<input type="text" name="name" value="${params.name}" id="name" />
<g:textField name="name" value="${params.name}" />
Are there any circumstances under which using g:textField would add value? Am I missing something?
The textField tag is provided as a convenience (slightly shorter than writing the HTML input) and is there to provide a full set of form tags. Personally I prefer to write as much plain HTML as possible in my Grails views and only tend to use the tags that really offer a benefit such as the form tag. I have not found an instance where using textField would have added any value outside of requiring a few less characters to type.
<g:textField /> is not shorter as plain text field tag, except id attribute will be attached automatically.
However, I recommend you to use customized tags associating the bean values with input fields. That shortens the code a lot. For more information you can read http://www.jtict.com/blog/shorter-grails-textfield/
Also you can find useful stuff in Form Helper Plugin
Is it mandatory in struts2 to use struts-tags. I mean can't we use following:
<td bgcolor="DEDBC6"><div align="left"><font color="#000000"><strong>
Employee Name * :</strong></font></div></td>
<td><input name="empname" type="text" id="empname" size="32"></td>
instead of following:
<s:textfield label="Employee Salary " name="empsal" required="true"/>
I had tried both but when i used 1st i didn't get validation message i.e "empname is required" that i wrote in action-validation.xml although validation is working well.
please comment ?
No, it is not mandatory. In fact a lot of struts2 users are sufficiently dissatisfied with OGNL and choose to use regular HTML instead.
But using the standard HTML tags has the drawback of loosing some functionality, after all that's why the custom tags are there in the first place. It is possible to get validation through validate methods on the controller class even with standard HTML.
If you are just starting out with the framework I suggest you learn the struts tags properly before going off the beaten path.
Is it mandatory in struts2 to use struts-tags.
No, but if you aren't using tags at all then you're not really getting very much out of Struts as a framework. Might as well do it yourself.
i didn't get validation message
If you're using your own markup you'll have to tell it to display the error message. eg.:
<s:fielderror><s:param>empcode</s:param></s:fielderror>
please comment ?
Please stop asking the same questions over and over again.
I don't see why you need any tags at all. Couldn't you just use Struts to generate JSON result types and then use calls to those in your otherwise static jsp pages using JavaScript and JQuery?