I need to use InputTextarea PrimeFaces component, wich allow use autocomplete mechanism between text. All works great, except for p:statusAjax, when I'm typing, my loading var animation blocks screen.
I resolve this for AutoComplete PrimeFaces component by adding next lines between p:autoComplete:
<p:ajax event="query" global="false"/>
But when I try put this line between p:inputTextArea JSF shows error:
javax.servlet.ServletException: /notificaciones/edit.xhtml #162,50 Event:query is not supported.
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:606)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)...
I've read PrimeFaces User Guide but for inputTextArea component there is no Ajax Behavior Section.
So, how can I know which event is firing when autocomplete method executed on p:inputTextArea
Most of the time, the documentation is up-to-date so most likely there is no ajax event. But to be sure, you can always check the javascript source and/or the java source of the component (the source is open and freely accessible).
You can always try without an event name to see if ajax is supported at all since all (most?) components have a default event.
I'm in a good mood and A quick check for you in the java source and the forms.js javascript source of 6.1 (which contains the js for this component and which is split in its own forms.inputtextarea.js in the 6.1.3 Elite and upcoming 6.2 release) does not show any ajax events being used, so I think you are out of luck on this and need to file an enhancement request in github
Related
I would like to dynamically set an error page in JSF. Specifically what I would like to do is whenever I get a ViewExpiredException to refresh the page. I am currently using omnifaces FullAjaxExceptionHandler to manage my exception but it reads the error pages from web.xml.
Is there an easy way to do this?
Should I consider client side navigation by using onError event or just overwrite FullAjaxExceptionHandler.findErrorPageLocation ?
It reads error pages from web.xml because that's the standard way how they are used if you didn't use JSF ajax in first place. In other words, the FullAjaxExceptionHandler ensures that the exception handling and error page presentation behaves exactly the same as if when you wouldn't be using ajax by e.g. <h:commandButton> without <f:ajax>, or <p:commandButton ajax="false">, or because enduser has JS disabled.
You can indeed control it by extending the exception handler and overriding findErrorPageLocation method, but then it won't behave anymore the same way as the standard way.
Alternatively, and likely a better way in your specific case, is to just specify a specific error page for ViewExpiredException and grab the initial page by the usual request attribute and let JavaScript redirect to it on page load.
<h:outputScript>
window.location = "#{requestScope['javax.servlet.error.request_uri']}";
</h:outputScript>
As a bonus, it will work exactly the same way as when you wouldn't be using JSF ajax.
I only wonder how this all would improve the user experience. This is likely only more confusing to the enduser; a page which reloads itself without any additional feedback when the session has expired during a postback.
I have used JSF 1.2 but new to JSF 2.0 . It seems like JSF 2.0 seamlessly supports ajax functionality via <f:ajax> but I am not clear yet how ? I would like to understand what makes these two powerful technologies to work so nicely together ? How does the two lifecycles interact ?
P.S: I am familiar with ajax and javascript. So you can base your answer on that premise.
The question is really broad and I would suggest to search for the appropriate tags to understand its usage in real situations. BalusC has contributed much here on stackoverflow and has also written excellent tutorials that Xtreme Biker made a reference to.
Due to abscence of answers I would offer a basic vision of how ajax works within JSF. There is a special Javascript library in JSF which makes it possible to perform ajax calls to the server with jsf.ajax.request(...). To ease development, there are components that you may attach ajax behaviour to. Typically you will use <f:ajax> tag on the component of your choice, like <h:commandButton>, to add ajax functionality to it.
In the old times we would send an asynchronous XMLHttpRequest via get or post to the server and wait until server sends us postback data which we will get most typically in JSON or XML format for client'side processing and update the view via document.getElementById(...) or by more convenient methods introduced by modern Javascript libraries. I think that in the end this is what JSF does behind the scenes.
In JSF 2.0 <f:ajax> tag was introduced which helps partially submit data, process it on server and partially update your view. For this the ajax tag has the following most important features/attributes: <f:ajax execute="..." render="..." event="..." listener="..." onevent="..." />. Let's take a closer look on all of them.
execute attribute tells JSF about what elements should be updated/processed on the server during this request by specifying a list of element ids;
render attribute tells JSF which components shall be replaced after ajax call is finished - the new elements that were rendered on the server shall replace the old ones with specified ids after partial page update;
event attribute defines events on which an ajax call shall take place, for instance, in case of a command button the event may be a click event, in case of an input text field the event may be a keyup, or blur event;
listener attribute defines a binding to a managed bean method of type public void processAjaxRequest (AjaxBehaviorEvent event) { } that will be triggered on ajax request and executed on server, before partial page update is done;
onevent attribute defines a javascript function to call during different phases of ajax request.
You may consult another excellent tutorial written by Marty Hall on ajax here.
I didn't intend to make an overview of ajax features in JSF 2.0, but rather to make a short introduction to get a basic grasp of ajax functionality.
I have becommen the SocketTimeoutException, which is quite hard to replicate now, but it is not the most important here. What is troubling me is the reaction of the PrimeFaces UI on such happening. The UI got frozen, so no AJAX clicks were processed (one could click what one will but nothing happened).
I don't know the PrimeFaces internals well, but with my experience with AJAX apps, it could happen where we have the AJAX queue and the job is not released after unexpected error happens. Is it the case here?
And how to prevent such behaviour? Or if prevention is not possible, is it possible to "restart" the AJAX engine of PrimeFaces in Javascript? As the last resort I could provide the special button to "reset" the AJAX state without "refreshing" (which should be rather called destroy-all-my-changes) the site?
First of all I'm still learning the structure and how it works.
I searched around the web to get an suitable and easy answer to the following question:
Is there a way to regonize all other basic ajax events, like hovering and clicking on Primefaces Components?
For example, i would know the event which get invoked if you click on the previous or next button on an <p:schedule>. The documentation says there are only "dateSelect, eventMove, eventResize" and "eventSelect" as callable ajax events. But this is not enough, if you want to build an complex application and you combine an <p:calendar> with an <p:schedule>. There you need to know when the schedule switches the month or year.
I hope someone can give me an clear and understandable answer to this.
Thanks and best regards.
Since you did not specify what event you need, your answer is going to be as clear as the question.
The primefaces objects can only recognize the events they are programmed to. If you need to get a specific type of event, you can:
1) see if the primefaces support that event. put it in a <p:ajax tag, and see if it works.
2) see if the standard JSF ajax API support it.
3) If all else fails, you can try to put a jQuery script along with the page, to handle the event and make a call from the client side.
The <p:calendar and <p:schedule makes heavy use of jQuery plugins to render it, I doubt you can get the events on the month selector or anything else in the rendered interface without client-side jquery.
I want to upload a file using the < s:file > tag, but Struts2 doesn't support Ajax for this functionality, as far as I know. I tried to do it using the Struts2 jquery plugin but it overwrites some jquery functions that i need an can't change right now (like .dialog()).
Is there an alternative way to do it?
There are many jquery based plugins for this purpose.
I am using this library. Its the most simple and elegant plugin, minimal requirements and lots of options.
Here are some other plugins which I considered(my preference was a plugin which doesnt use flash)
This one shows thumbnail before uploading and also overall progress
This one shows remaining time, uploading speed and remaining size
This is how I do it (I'm not using JQuery):
I hide an iframe inside my page. I give it an id (iframe for example) and a name (the same than the id).
I set the attribute "target" on my form to the id of the hidden iframe (then, the response from the server is loaded inside the iframe.
I register an event handler on the iframe to react on the onload event. The handler analyse the response from the server. Alternatively, I sometime just return javascript code from the server in a <script> tag. This code performs action on the client upon success or failure of the intended action.
If you like the idea, you may want to read this article or this one: