I have 3 log files and a selectone Menu.Based on the selection, the last part of any one of the log file needs to be displayed dynamically.Which PrimeFace component will do this and how.
There is no stand alone component for this in primefaces, you should use a few basic principals.
Read the last lines of a log file, you may see this question Java IO implementation of unix/linux "tail -f"
When reading file you should store the lines read to a collection of strings in your managed bean
On selection of your selectOneMenu, you should change your filename and regenerate your collection, again on the same managed bean.
On ajax complete event of your selectOneMenu ("update" attribute), you should update a jsf display component which links to your collection.
Related
I am very new to JSF. I have the following requirement:
On click of a commandButton, call a backing bean method to check if there is some data present satisfying the condition.
If yes, confirm from user for overwrite.
If user says OK, call the same method of backing bean with some parameters set to tell the program to overwrite the data.
What I am doing is:
having action of the commandButton as the method name.
in the backing bean method, check if we have come with certain condition, check if the data is already present.
If yes, go back to page and ask for confirmation.
If confirmed, call the click method of the button.
The problem is, when I come back to the page, the inputFileUpload component on the page loses its value.
What can I do to achieve this? Please help.
This is fully by HTML specification and completely outside control of JSF. It's by HTML specification for security reasons not possible to (re)display the value of a HTML input file field with a value coming from the server side. Otherwise a hazard scenario as shown in this answer would be possible.
You need to redesign the form in such way that the input file field is not been updated during confirmation. You can use among others JavaScript/ajax for this: just submit the form by ajax and make sure that the input file field is not been updated on ajax response.
I'm looking for a ready made, freely available component that provides the following features:
editing list entries
deleting entries
adding a new entry - possibly invoked multiple times
bind to property in managed bean of type List, or similar
optional: reordering entries
optional, simple: allow verification that at least one element is entered (required="true"? required="1"?)
optional, better: restrict by minimum and maximum allowed number of elements
The simplest way to allow editing entries would be to represent them as input element. Preferably the element won't need to sync to the server for every change in the number of elements.
Alternatively: is there a trivial way to create or compose such a component oneself?
If this if of importance: currently I'm using Richfaces 3.3.3 and MyFaces 2.0.
Edit: The component is expected mostly to be used for creating new lists from scratch, so that should be as simple for the user as possible. Preferably just tabbing to the next empty input element automatically created at the end of the list. I'd like to use the component for editing these lists, too, but that feature is expected to be used much less often.
You could take a look at Primefaces p:collector. The example in the Primefaces showcase is a good starting point. It can be used for adding elements to a list and for editing and removing these elements.
Probably the simplest way that I would know of going about almost all of these is the PrimeFaces dataTable component. With the exception of adding and deleting entries inline, all of this comes out of box. Deleting entries can be as simple as adding a delete button in a row and adding entries can be done through invoking a modal dialog with a form to create a new entry, add it to the backing bean list for the table, then asynchronously updating the dataTable.
http://www.primefaces.org/showcase/ui/datatableHome.jsf
It really does seem to be the most fully featured JSF dataTable component out there.
I have a page with a file upload input from tomahawk's components. I want to know if putting 5 upload inputs with a single button those will be sent as part of the form.
And I want also some ideas on how I can make my managed bean to adapt for this multiple file upload.
Thanks in advance.
I think you can just simply map each file to different variables in your backing bean. When the user clicks submit button, you can get all your files from these variables at 1 go.
PrimeFaces' upload component manages multi-upload.
I am trying to implement an audit trail functionality for my web application that records:
lastModified (timestamp)
modifiedBy (user information)
userComment (reason for value change)
for each of my input fields (input fields are spread over several forms with different backing beans and different valueHolder classes).
The first two (lastModified and modifiedBy) are easily done with the help of an JPA AuditListener and #PrePersit and #PreUpdate methods.
The third one is a bit tricky since it requires user interaction. Best would be a dialog that asks for the user comment.
So there are (at least) two open issues: Can I establish a "global" valueChangeListener for all input fields in my application? Is this possible without attaching <f:valueChangeListener> to each single input component? Second: How can I grab the user comment. My idea is to put a p:dialog in my web page template but this dialog needs to know from which input component it is called.
Can I establish a "global" valueChangeListener for all input fields in my application? Is this possible without attaching to each single input component?
Yes, with a SystemEventListener which get executed during PreRenderViewEvent. You need to walk through the component tree as obtained by FacesContext#getViewRoot() to find all components which are an instanceofEditableValueHolder (or something more finer-grained) and then add the new YourValueChangeListener() by the addValueChangeListener() method. See also this answer how to register the system event listener: How to apply a JSF2 phaselistener after viewroot gets built?
Second: How can I grab the user comment. My idea is to put a p:dialog in my web page template but this dialog needs to know from which input component it is called.
You could in YourValueChangeListener#processValueChange() set the component in question as a property of some request or view scoped which you grab by evaluateExpressionGet().
Recorder recorder = (Recorder) context.getApplication().evaluateExpressionGet(context, "#{recorder}", Recorder.class);
recorder.setComponent(event.getComponent());
// ...
It will execute the EL and auto-create the bean in its scope if necessary. The bean in turn should also hold the property representing the user comment. Finally, you can use it in your <p:dialog>.
<p>You have edited #{recorder.component.label}, please mention the reason:</p>
...
<h:inputText value="#{recorder.comment}" />
I have a widget in my application that I need to display at two places(once in main page body and once through dialog box). Currently its code has been added twice in the page. Now I was thinking, If there was a way I could just include it only once and show the same instance in the dialog box, as in the main page body.
Can you suggest a way for this?
I'm Using:-
JSF 2.0 with Facelets
Primefaces 3.0 M3 Snapshot
JSF 2 has exactly the feature you want: it's called composite components. I bascially allows you to write a bunch of Facelet code into a file and use it just like any other JSF component, pass parameters to it, etc.