I am currently evaluating Wicket and I am trying to figure out how things work.
I have a question regarding form submit and panels (or other components).
Imagine a custom wicket panel which contains a text field, doing as-you-type validation using ajax. This panel is added to a form.
How can the Panel react a form submit (let's say because javascript/ajax is unavailable)?
I am currently only aware of one solution: calling a panel's method inside the Form onSubmit() method. But this seems not like a "reusable" approach here, because I have to add boilerplate code to every form's onSubmit() which contains the panel (and every developer which use the panel must know this).
So here comes my question: Is there any way that a Panel/Component can "detect" a form submit in some way? Or is there any other solution beside this?
Thank you.
Make your panels implement org.apache.wicket.markup.html.form.IFormModelUpdateListener, and the updateModel() method should be called when the containing form is submitted and passes validation.
There's a good example of code using this by one of the wicket authors at the Wicket In Action blog.
Well, you could simply do the following:
Panel{
Form{
onSubmit(){
Panel.this.onSubmit();
}
}
protected void onSubmit(){}
}
...
This means that any panel that extends your panel need only override the onSubmit and the form no matter what it is in html will call that method. That way you can extend the panel and only override one method for each form.
With regard to form components, the framework handles it for you transparently. Forms are aware of any child form components, even if they haven't been added directly to the parent form.
I would have a Form inside that Panel. This way, you can reuse that Panel without requiring an external Form. As Forms can not be nested inside each other in HTML, Wicket will swap the inner Form(s) into 's transparently, but will make sure that each of the inner Forms takes part of the form processing (validation,..).
You can override the OnSubmit() function of the Form in your Panel. Wicket will call it for you.
what do you mean by "react"? I have only started recently with Wicket, but FWIK, form submit updates the model of a component, and then it calls onSubmit(), which you can override to take special actions beyond that. See Wicket in Action, chapter 6.
After that, the page (and it's components) get re-rendered, using the updated model, so basically, they really "react" on a submit, with quite few lines of code.
For your mentioned case with Component in a Form, have a look at the CompoundPropertyModel.
Implementing IFormSubmitListner and IFormModelUpdateListener shall call the respective methods during a form submit.
However, if you want to do some processing after form submit, I'm afraid you have no choice but to write some boilerplate code yourself.
Related
I am rather new to ASP.NET MVC5. I know server side controls are not working directly in MVC, but there will be some way by which we will get similar controls in MVC5 for rapid development. Can you suggest me how can I find such controls? Can you list out all such mostly used common controls for MVC5?
Thanks in advance.
There's no concept of a "control" in MVC. There's various things that function similar to Web Form controls, but it depends on what you're trying to do.
HTML Helpers are similar in that you essentially call a function that returns rendered HTML. You can extend HtmlHelper to add your own.
Child actions function as a sort of separate request within the context of the main request. They accept parameters like an action, can do all the backend stuff an action can do (query database, etc.) and return a view rendered based on a model, like a normal view.
A partial view, in general, can function as a control as it allows you to insert a snippet of HTML somewhere.
Editor templates and display templates can be used in conjunction with Html.EditorFor and Html.DisplayFor, respectively to render a form field or some sort of HTML display for a particular property on your model.
I have a simple ContactEditPanel which contains a form and a number of textfields. Up until now I included an AjaxSubmitLink in this panel which, if the form content is valid, saves/updates the Contact instance contained in the Panel model. So far so simple. However now I'd like to remove the link in order that I may, depending on the context in which I use the ContactEditPanel, place the submit link at different levels of my overall component hierarchy. For instance in one context I'd like to use to flip between ContactEditPanel and ContactViewPanel with a bar of actions above the current view (edit | save , cancel). Another context would be to use ContactEditPanel in a standalone way (maybe part of a multi-step process) with just a save link below.
I was contemplating refactoring my ContactEditPanel to extends FormComponentPanel rather than Panel as described here but I'm not sure whether this is the right approach and I'm having trouble wrapping my head around this.
Any help would be most appreciated!
Many Thanks,
A
Your using the panel like a FormComponent so extend FormComponentPanel, it will allow you to keep all the validation you write contained to the component and also allow you to reuse it as you wish.
Just think of it as you've created a new FormComponent, like a TextField or DropDownChoice.
I' working on a library control for Xpages and need some help in creating.
I would create a control which reads a configuration file and creates controls in a table, controls like Editboxes, checkboxgroups and so on.
so and now to my questions:
could I initiate controls from the Exlib or must I implement them all by my self?
if I could use them from the Exlib could anyone explain me how?
I hope its clear what i mean if not please ask me for further informations.
When creating your own components, if you're closely replicating some behavior that is already in an extension library component, I highly recommend you extend that component and just add what's needed to accommodate your different functionality. This makes things much easier and you don't have to code around every little scenario that the component might be placed in.
But, if you are developing a component that is nothing like any of the extension library or core components then just ensure your component extends UIComponent or UIComponentBase. If going this route, you'll also need to create your own renderer which extends Renderer. This is what will build the on-screen representation of your component. Again, if there's already something in the core components or extension library components that closely mimics what you need then make your renderer extend that renderer. Also, don't forget to include the renderer definition in the faces-config file and the component definition in the xsp-config file or your component won't work.
As for initiating controls from the extlib.... I assume you mean can you inject them onto the page at runtime. If so the answer is absolutely yes. To add an input text field to the page where there is a container (i.e. panel, div, span, whatever) with an ID of "someContainer"
XspInputText input = new XspInputText();
input.setValue("someValue");
input.setId("someID");
UIComponent container = FacesContext.getCurrentInstance().getViewRoot().findComponent("someContainer");
container.getChildren().add(input);
To see the api for all of the core and extension library components take a look at the XPages Controls Documentation. For a more complete tutorial on creating your own components take a look at my blog for creating a custom component inside an nsf, the steps are pretty much the same for putting them into a library:
Part 1,
Part 2 and there is an example database in the Part 2 post.
I have a form which one of it's fields is a code and description, also a button for opening a popup window that contains a list of all of the available codes.
when the user double clickes a row from that table i want to set these values to the code and description. - how can this be done?
Another question, I want to create this popup and table to be initialized dynamically - by that i mean that if i have a few forms in my application, when ever i have a field which has a description i want to be able to open this popup and to see the available list for that field. (every field can be from a diffrent table). is it possible to create something like that? if so, how?
Any help will be appritiated,
Thank's In Advance.
Yes, it is possible. Even more, many component libraries have ready to use popup/dialog components, such as RichFaces with <rich:popupPanel> and PrimeFaces with <p:dialog>.
If you do not want to use a component library for some reason, you would need to create a custom component for this which generates basically an absolutely positioned HTML <div> element with a CSS overlay which get shown/hidden by JS on a particular click/action. The HTML/CSS/JS part should be relatively simple if you are familiar with those languages. The JSF part is somewhat hard if you have never created a custom component before, but it should be possible with a composite component as well, so you could also just create one with pure XHTML. The updating/refreshing can just take place by the usual <f:ajax> means.
I have links and pictures related to these links on my page. I want to change the pictures everytime when onmouseover event occurred in the links. I want to do this in JSF.
A lot of Thanks to everyone.
You are looking specifically for JSF to do it, or you are open to other Javascript frameworks that provide a slick and easy solution on this? For example Jquery and Dojo etc may be easy to incorporate in your application and will give Rich UI effects.
On the other hand if you are looking at JSF specifically for these UI effects than probably I can try to think of some ways and let you know.
JSF isn't designed directly to do this; It's designed to give you the tools to do this yourself. In order to do this you would need to create a custom JSF component to do this and you would use Java script to do it.
You could possibly find a JSF framework that does this already (a4j, IceFaces, etc.) but this is such a simple and well documented JavaScript thing that just tossing a little Java script among your JSF is perfectly acceptable. However, if you don't want to reinvent the wheel, take a look at those other options.
Javascript solution:
Define onmouseover event on the commandLink tag calling some kind of javascript you may give link address from like onmouseover="doSomething('addressOfImage')" then in doSomething javascript method, first find the image, then set src attribute of a default image to given address.
JSF Solution:
You might want to use a4j for this.
Add a4j:support to link for onmouseover event then just rerender graphicImage component ofcourse you need to give value of graphicImage dynamically. There is an example of using a4j support below. You can add this a4j:support between your link tags for mouseonover event. Then manage everything on backing bean to handle which image to be displayed.
example
<h:graphicImage id="imageToBeRendered" value="#{myBean.imageAddress}"/>
Just google a4j if you have no idea.