XPage OSGi/Open Source Conventions - xpages

Seeing as how there is a pretty cool XPage open source development community, I was wondering something. Are there any special conventions that we should be adhering to other than the java specific ones? I am referring to those regarding package names, class names etc.

To my knowledge, there aren't any really strong conventions among XPages development on top of the usual Java ones (name your packages after your DNS name, etc.). The only ones I can think of off the top of my head are minor and optional things, like using an "xsp" sub-package for frameworks/utilities that are XPage-specific (e.g. "com.ibm.xsp", "org.openntf.xsp", etc.). Beyond that, things are a conflicted mess, even just looking at what ships with XPages: some interfaces named "IFoo", some just "Foo"; some classes named "Foo", some "FooImpl", some "FooImplEx2".
In lieu of a community standard, I un-biased-ly advise you to adopt all of my personal conventions, as reflected in the frostillic.us framework and (mostly) the OpenNTF Domino API. So: no Hungarian notation, no "IFoo", no "FooImpl" (barring a compelling reason), Java code style similar to https://code.google.com/p/google-styleguide/source/browse/trunk/eclipse-java-google-style.xml , and final method parameters.

We name our java classes:
com.domain.whatever.Name
In faces-config I always want to capitalize my Managed Beans:
<managed-bean>
<managed-bean-name>CurrentJob</managed-bean-name>
<managed-bean-class>com.domain.inventory.Job</managed-bean-class>
<managed-bean-scope>session</managed-bean-scope>
</managed-bean>
That's all I have really. :)

Related

BootsFaces tag auto completion shows duplicate properties style-class and styleClass

Check the below screeshot,
why is there for instance style-class and styleClass?
I am using bootsfaces 0.9.0-SNAPSHOT
Both versions are identical. Most web designers prefer the style-class version for their CSS class names. CamelCase is a tradition of Java developers. We felt that it looks odd to use CamelCase among all these boot-strap-css-classes. So we decided to implement the hyphen version as an alternative to the traditional CamelCase attribute names of JSF. We hope that it allows you to write files that look nicer, and maybe the attribute names are easier to memorize.

ExtLibUtil documentation - where do you find what the available functions are?

As I have asked questions in this form - thanks for your many helpful answers - i have found many really neat things that one can do using ExtLibUtil.???? however, other than a bit here and a bit there I have not found anything that gives a listing on the various functions. I one post I read that it is all in the source of the extension Library, and it might be if you really understand where in the source to look. Sure would appreciate a pointer and starting point.
I've been unable to find a JavaDoc for it. The library slipped passed us when we wrote the book - certainly I was not as au fait with Java to be aware of it and all the strength within it. So the best option currently is to look at the source code in Eclipse. Many of the methods are helper methods to easily access things like viewScope etc, which is easy from SSJS but less easy from Java. Most are pretty self-explanatory.
Content assist doesn't seem to work from SSJS, but will from any Java class or, alternatively, open up one of the Java classes created for XPages / Custom Controls under the "local" package in Package Explorer, type "ExtLibUtil." in any method and you'll see the list.

Naming conventions for `<component-family>` and `<renderer-type>` while creating custom JSF components

I am learning to create custom JSF components and have been successful in creating simple ones. One thing I would like to know is that whether there are any naming conventions to be followed while defining <component-family> and <renderer-type> for your component?
For e.g. for combo box the <component-family> is javax.faces.SelectOne. It looks like a Java class but I was unable to find any such class in JSF API.
They do indeed not necessarily represent class names. They are just identifiers. The javax.faces prefix hints in this case merely that it's part of standard JSF API. The same prefix is used everywhere else in standard JSF API. PrimeFaces components use org.primefaces prefix, OmniFaces components use org.omnifaces prefix, etcetera.
You're fully free in choosing your own for your component library. You should only gurarantee that it shouldn't possibly conflict with a 3rd party one which may be mixed by the enduser. Like as with package structure of Java classes, it'd make sense if you choose for com.naveen prefix or whatever what/who represents the owner/developer of the component library.
The same approach as Java packages (and Internet domain names) is a very sensible way of guaranteeing uniqueness (you know, identifiers are supposed to be unique).
See also:
How do I determine the renderer of a built-in component
What is the relationship between component family, component type and renderer type?
Java packages com and org

What makes a portlet JSR-286 compliant?

Does anyone have a link to a concise summary of what makes a portlet "JSR-286 compliant" vs being only "JSR-168 compliant". I've got a copy of the spec and that's anything but concise so linking the spec is not a useful answer. I've searched the web for an hour now and I've found nothing that is clear (aside from the spec, which of course requires that you read the previous spec too, and then weed out the "new features" from the "required compliance".
Particularly I've found that there's quite a bit of confusion out there on the necessity of web.xml, which appears to come from people using Liferay and not realizing that Liferay is dropping in a web.xml for them.
Do JSR-286 portlets require a web.xml file in their WAR files?
What I'd really like is something that contains one or more of the following lists:
Things you have to do to a JSR-168 to make it become JSR-286 compliant
Things you must not do, that would cause an otherwise JSR-286 compliant portlet to be considered only JSR-168.
You can leave "use the portlet-app_2_0.xsd" off the list, as I consider that part obvious.
I'm open to the answer that both lists are empty aside from the DTD/xsd for portlet.xml, and the difference is only in what the portal supports, but please back that assertion up with a link or other reference.
The reason I care is I see posts about Vaadin portlets in Liferay that imply that some features are not available for JSR-168 portlets... It may also be that some logic in Liferay switches based on which version of portlet.xml it sees, but I haven't confirmed that either so that would be interesting information too, but not the answer to my question.
According to this doc, but it's also mentioned in jsr286:
The JSR 286 spec(Portlet 2.0) does not break binary compatibility with JSR168(Portlet 1.0). This means that all portlets written against the Portlet 1.0 specification can run unchanged. The only exceptions to this rule are:
renderResponse.setContentType is no longer required before calling getWriter or getOutputstream. In JSR168, calling getWriter or getOutputstream without previously setting the content type resulted in an IllegalStateException.
getProtocol for included servlets / JSPs returns ‘HTTP/1.1’, In JSR168, it returned null.
So as long as your jsr168 portlet doesn't depend on the value returned by getProtocol() you're safe (ie every jsr168 portlet is a jsr286 portlet).
The posts you see seem to be logical as jsr286 is a newer spec and there are some features that make jsr268 portlet not a jsr168 portlet.
Ok, Since I've not found anything new that distinguishes a 2.0 portlet from a 1.0 portlet (aside from using additional services and ) I'll begin the lists for my answer here.
Must Do:
Conform to the 2.0 XSD for portlet.xml (xmlns="http://java.sun.com/xml/ns/portlet/portlet-app_2_0.xsd")
Must Not Do:
Rely on getWriter throwing an exception if renderResponse.setContentType has not been called yet. (Seems unlikely anyway)
Rely on getProtocol() returning null
The upshot is, if you simply convert your portlet.xml, you are now "286 compliant" unless you relied on the two items in the second list for your program flow. I can't find anything else, but if someone finds another item for these lists, please edit.

What are the principles of developing web-applications with action-based java frameworks?

Background
I'm going to develop a new web-application with java. It's not very big or very complex and I have enough time until it'll "officially" start.
I have some JSF/Facelets development background (about half a year). And I also have some expirience with JSP+JSTL.
In self-educational purpose (and also in order to find the best solution) I want to prototype the new project with one of action-based frameworks. Actually, I will choose between Spring MVC and Stripes.
Problem
In order to get correct impression about action-based frameworks (in comparison with JSF) I want to be sure that I use them correctly (in a bigger or a lesser extent).
So, here I list some most-frequent tasks (at least for me) and describe how I solve them with JSF. I want to know how they should be solved with action-based framework (or separately with Spring MVC and Stripes if there is any difference for concrete task).
Rendering content: I can apply ready-to-use component from standard jsf libraries (core and html) or from 3rd-party libs (like RichFaces). I can combine simple components and I can easily create my own components which are based on standard components.
Rendering data (primitive or reference types) in the correct format: Each component allow to specify a converter for transforming data in both ways (to render and to send to the server). Converter is, as usual, a simple class with 2 small methods.
Site navigation: I specify a set of navigation-cases in faces-config.xml. Then I specify action-attribute of a link (or a button) which should match one or more of navigation cases. The best match is choosen by JSF.
Implementing flow (multiform wizards for example): I'm using JSF 1.2 so I use Apache Orchestra for the flow (conversation) scope.
Form processing: I have a pretty standard java-bean (backing bean in JSF terms) with some scope. I 'map' form fields on this bean properties. If everything goes well (no exceptions and validation is passed) then all these properties are set with values from the form fields. Then I can call one method (specified in button's action attribute) to execute some logic and return string which should much one of my navigation cases to go to the next screen.
Forms validation: I can create custom validator (or choose from existing) and add it to almost each component. 3rd-party libraries have sets of custom ajax-validators. Standard validators work only after page is submitted. Actually, I don't like how validation in JSF works. Too much magic there. Many standard components (or maybe all of them) have predefined validation and it's impossible to disable it (Maybe not always, but I met many problems with it).
Ajax support: many 3rd-party libraries (MyFaces, IceFaces, OpenFaces, AnotherPrefixFaces...) have strong ajax support and it works pretty well. Until you meet a problem. Too much magic there as well. It's very difficult to make it work if it doesn't work but you've done right as it's described in the manual.
User-friendly URLs: people say that there are some libraries for that exist. And it can be done with filters as well. But I've never tried. It seems too complex for the first look.
Thanks in advance for explaning how these items (or some of them) can be done with action-based framework.
I'll do my best to answer regarding Stripes. I've used Struts and JSF in the past, but not recently, so at best I have vague notions and feelings about them.
We are intimately familiar w/ Stripes, use it for most everything now, and really enjoy it. It is easy to jump into, supports many of the complicated scenarios, but you are also free to work OUTSIDE of it, which is really important when you want to build your own ajax widgets or talk to another system or something.
If you go the stripes route, I definitely recommend buying or download the book. It is a one stop shop for everything you need for Stripes, and is practically the only documentation for Stripersist (really nice feature, but NO web docs).
Rendering content: I can apply ready-to-use component from standard jsf libraries (core and html) or from 3rd-party libs (like RichFaces). I can combine simple components and I can easily create my own components which are based on standard components.
This is similar. Core, Html, Fmt, etc. as well as any custom tags you find, inc. display:tag, pack tag, and create your own. However, obviously you do not deal at the component level now, you deal with a tag that determines what is on the page / sent to or from the server.
Rendering data (primitive or reference types) in the correct format: Each component allow to specify a converter for transforming data in both ways (to render and to send to the server). Converter is, as usual, a simple class with 2 small methods.
Stripes has many built in converters, and it is easy to create custom converters for your more complex data types. Stripes supports very complex data structures to be mapped with little hassle. Combined with Stripersist, for example, I can put my model object directly on the ActionBean, put a few of the fields on the form, and Stripersist will hydrate the model from the db (based on its PK) and update that with the fields I put on the form - all before releasing control to me on the ActionBean.
Site navigation: I specify a set of navigation-cases in faces-config.xml. Then I specify action-attribute of a link (or a button) which should match one or more of navigation cases. The best match is choosen by JSF.
Navigation in stripes is based on what you name the ActionBeans, initially. There is no xml. Additionally, pretty urls are an annotation at the ActionBean level in Stripes 1.5, so you can do things like #UrlBinding("/{$event}/{model}") where /view/5 would take you to the "view" event handler for your Model object with the ID/PK of 5.
Implementing flow (multiform wizards for example): I'm using JSF 1.2 so I use Apache Orchestra for the flow (conversation) scope.
While I only am vaguely familiar with the concept of conversation scope, Stripes has Wizard Form functionality, but I haven't used it and am unable to really expand on that. I think it is a similar idea though.
Form processing: I have a pretty standard java-bean (backing bean in JSF terms) with some scope. I 'map' form fields on this bean properties. If everything goes well (no exceptions and validation is passed) then all these properties are set with values from the form fields. Then I can call one method (specified in button's action attribute) to execute some logic and return string which should much one of my navigation cases to go to the next screen.
Not drastically different. Instead of components on your [action] bean, you now have Java or custom types. ActionBeans are created per request and thrown away, unless you do something like put it in session, or wizard, or whatever. This is nice, because all the instance variables get mapped to the data from the form, you use it, then throw it away, and don't have to deal with any synchronization issues like struts did. After you do your thing with the data, Stripes lets you send a ForwardResolution (OK status), Redirect, or Streaming (JSON, file, etc). The Redirect-after-POST pattern is implemented nicely with the idea of flash scope (3/4 down the page).
Forms validation: I can create custom validator (or choose from existing) and add it to almost each component. 3rd-party libraries have sets of custom ajax-validators. Standard validators work only after page is submitted. Actually, I don't like how validation in JSF works. Too much magic there. Many standard components (or maybe all of them) have predefined validation and it's impossible to disable it (Maybe not always, but I met many problems with it).
Stripes allows validation in annotations on the instance variables on the ActionBean. They allow some defaults, required, maxlength, etc. or you can always create your own. The default is easy to add and flexible, while there is always the ability to make something completely customized.
Ajax support: many 3rd-party libraries (MyFaces, IceFaces, OpenFaces, AnotherPrefixFaces...) have strong ajax support and it works pretty well. Until you meet a problem. Too much magic there as well. It's very difficult to make it work if it doesn't work but you've done right as it's described in the manual.
This was my big problem with the JSF way of doing things. Even if you did get the widget right, you're still stuck with THAT widget. With Stripes, you can use whatever latest and greatest Jquery has to offer, and as long as you send the right GET or POST to the server, stripes knows what to do with it and can easily send JSON back. I think component frameworks fit a niche a few years ago much better when AJAX was hard, but JQ makes it so easy now.
User-friendly URLs: people say that there are some libraries for that exist. And it can be done with filters as well. But I've never tried. It seems too complex for the first look.
#UrlBinding, it's as easy as that.
My answer is not the one you want to hear: Don't switch from Component Framework to action framework
I switched the other way around after many years of action framework development and I'm never going back.
Of the 8 use cases you mentioned, only one comes to mind where Action frameworks are obviously better, and that is URL design / friendly URLs. It can be done in component frameworks as well, but much easier in Action Frameworks (especially in Stripes where you just annotate your ActionBean with the url).
I would advise you to try wicket, it is very easy to learn (much easier than JSF) and it let's you re-use many existing components as well.

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