I'm working on a web project which uses JSF 2.0, PrimeFaces and PrettyFaces as main frameworks / libraries. The pages have the following (common) structure: Header, Content, Footer.
Header:
The Header always contains the same menu. This menu is a custom component, which generates a recursive html <ul><li> list containing <a href="url"> html links, this is all rendered with a custom renderer. The link looks like 'domain.com/website/datatable.xhtml?ref=2'. Where the ref=2 used to load the correct content from the database. I use prettyfaces to store this request value in a backingbean.
Question 1: Is it ok to render the <a href> links myself, or should I better add an HTMLCommandLink from my UIComponent and render that in the encodeBegin/End?
Question 2: I think passing variables like this is not really the JSF 2.0 style, how to do this in a better way?
Content:
The content contains dynamic data. It can be a (primefaces) datatable, build with dynamic data from the database. It can also be a text page, also loaded from the database. Or a series of graphs. You got the point, it's dynamic. The content is based on the link pressed in the header menu. If the content is of type datatable, then I put the ref=2 variable to a DataTableBean (via prettyfaces), which then loads the correct datatable from the database. If the content is of type chart, I'll put it on the ChartBean.
Question 3: Is this a normal setup? Ideally I would like to update my content via Ajax.
I hope it's clear :)
It's ok to just output link yourself, commandLink is out of the question (it does a postback using javascript, it's not what you want);
Parameter are all in the param implicit object. You can insert them by a #ManagedProperty annotation, like this:
#ManagedProperty("#{param.ref}")
String ref
// .. getters, setters (obligatory!)
You can also use (if you are on JSF 2) the f:viewParam tag (a nice description http://blogs.oracle.com/rlubke/entry/jsf_2_0_bookmarability_view), you get the bonus of validation and conversion.
The way I understand it, your setup is rather complicated. Using a handwritten custom component for a menu is a huge overkill (at least judging from the provided description), a composite component would probably do. JSF has no special way of making ajax calls between views or embedding views one into another, so - unless you use iframes - your only choice would be to include all the possible pieces of content into a single view, wrapped in panels, and render them as required:
<h:panelGroup rendered='#{backingBean.ref == 2}'>
... content 2 ...
</h:panelGroup>
and so on. Careful, this would be heavy on resources.
You could also write your own ajax solution in javascript. This would require all the pieces of content to be fully independent views, with their own forms. Also, all their postbacks would have to go through ajax, so the main page does not get reloaded.
Related
I'm working on a vaadin page, but one of the elements I want to put in my VerticalLayout is a java.awt.Frame. Is there a way to do this in vaadin?
As said in the comments, you can't use Swing/AWT stuff in Vaadin since it will be converted to Javascript and DOM to be used in a browser.
If you get a hold on the JS file TeeChart uses you can basically implement a custom client-side widget that will use it.
Take the basic demo here what you have to take care of is that there is a <canvas> tag to render the content in and that the draw() is called at a phase when Vaadin is done creating the surrounding DOM structure.
Please have a look at this tutorial to get an idea on how to wrap a JavaScript library to a Vaadin component.
In my Vaadin application i want that user have possibility to store his login/password in browser local storage. So i implemented LoginForm like it was described here https://vaadin.com/forum#!/thread/1977417 in comment by Sohan Machielse and this appoach works great (thx Sohan). So now I want to add in this static html, that returned from connector request, existing vaadin component (combobox with language selection). So my question is how can i add vaadin component in static html?
I tried to add to this static html "div" with location attribute and wrap all my layout to Custom layout and then add ComboBOx on the place, described in location attribute, but it's not work. Maybe i am doing something wrong cos' i do not know how exactly CustomLayout add components to the page. Maybe someone could explain me how Custom Layout works...
Why You need to add Vaadin component exactly?
Vaadin components is AJAX, based on GWT. Embed it in pure html is not simply.
You can use simple html components "select" with language selector and return result in app.
I'm learning tapestry 5 web framework but I don't understand the principle 1 about it:
"Static Structure, Dynamic Behaviour", what does means it ?
If I don't add components to the components, how can I create a dynamic page?
anyone can help me?
Thanks in advance
It means that you can't choose or replace components at runtime effectively.
If, say, you'd want to build a portal solution where users could arrange components on a screen any way they wanted, Tapestry would not offer an effective way to do that, because components have static structure, i.e. you must define what goes into them at compile-time in their template file.
Or you might have a specialized menu for administrators, so you might want to just replace the Menu component with a derived component, AdminMenu - but you can't, you have to use if statements in the template or use a block to inject different menus into your layout component.
There's an anti-pattern related to this limitation: The God or über-component tries to solve this problem by effectively having a giant template file with all the available components, like this:
<t:if t:test="displayComponentA">
<span t:type="ComponentA" ... />
</t:if>
<t:if t:test="displayComponentB">
<span t:type="ComponentB" ... />
</t:if>
...
This, however, is horribly ineffective, as Tapestry assembles the entire component tree, including components that are not displayed, to do the rendering of the page.
Tapestry uses templates to define static content. These templates are usually html pages with placeholder variables which are replaced by some code dynamically by the framework. Templates allow for segregation of things that not change from the ones that change. Usually structure is less prone to change then behavior. Even if you want to change some element of a component dynamically you're going to use some component that itself is defined by a template that is dynamically filled with data. This dynamic data again can insert some other component etc.
Static structure doesn't mean that you cannot output dynamic content nor that you cannot add components to components. You just cannot add a component to another at runtime. You can define a page or component structure using other components, but this is all defined in the template, before the page is rendered, never while it's rendered. A component can choose not to render itself, to render part of its template (If and Unless components), etc.
One of the few practical situations caused by the static structure of Tapestry is that a component C cannot use another instance of the same component inside it.
i'm using struts (form) + validation
i just want to ask if can i set focus on some field on form after validation without javascript? i think i red something in book programming jakarta struts but i can't remember.
thanks
You cannot set focus on a certain field with pure HTML. The tabindex idea as suggested by Bozho is nice, but it will only work if you actually press tab for the first time. It has however the disadvantage that it changes the tabbing order of the input elements. Not really user friendly.
You'll really need to grab JavaScript for this. Just do something like:
window.onload = function() {
document.formname.${inputname}.focus();
// or:
document.getElementById(${inputid}).focus();
};
...where ${inputname} dynamically resolves to name of the input field as in <input name="foo"> and where ${inputid} resolves to ID of input field as in <input id="foo">.
That's all.
You can set the tabindex="1" attribute of the input which you want to have obtain the focus first, when the page reloads.
You can't set the focus on a field without using JavaScript. Others have tried and failed (CSS was the first place they looked at, but that doesn't cut it either).
Not sure what you've read in the book Jakarta Struts, but maybe you are referring to the focus attribute of the Struts <html:form> tag? That sets the focus on the desired form field without you needing to add JavaScript. But Struts will add the JavaScript, so that means no JavaScript from your side, and not no JavaScript at all.
Can i somehow add JSF tags to my JSF component renderer class? I'm trying in this way:
writer.append("<f:param name=\"active\" value=\""+tabName+"\"/>");
But, this tag is not recognized by compiler as JSF tag.
Adding JSF tag in renderer which is invoked in Renderer response phase is too late and won't work. You need to modify components tree in java or override renderer according what you want to do.
EDIT after comment
So you do this in jsf page like in this example. You need to notice that <f:param> need to be a child element of <h:commandLink> tag. I think your question is about to how to pass parameters to next page. This can be done by creating appropriate <f:param> way, or ususing hidden inputs fields like you do in Struts. In both cases you need to have field in backing bean to store the value or get it from request.