Deriving the ABAP data model class name from a Gateway service name

The assumption made here is that the Gateway service you are wanting to investigate has been created using the OData Channel technique (good ol' ABAP coding) and not by the Gateway model wizard!

The GAteway service name is the name that appears in the URL when executing the service from a browser.

The first thing you need to know is how your Gateway system has been installed.  There are two possibilities here. Since the Gateway software is nothing more than a set of ABAP add-ons, the first task is to determine whether all the software components exist on your backend business system, or whether the components have been split between your backend business system and a separate Gateway system.

1. Log on to your Gateway ABAP system and select System -> Status.
2. Select the "Component Information" button in the section "SAP System Data"
3. Scroll down the list looking for component IW_BEP.
4. If IW_BEP does not exist in the Gateway system, then you will need to locate the correct backend system with which the Gateway service communicates.

If the IW_BEP component has not been installed on your Gateway system, then you must log on to whichever system has this component.

1. In the system where component IW_BEP is located, run txn SM34 and enter the cluster name of /IWBEP/VC_MGW_SG.  Select "Display".
2. From the left hand navigation tree, select "Define Object Model Group".
3. The 3rd column lists the external service name seen in the URL.
4. Scroll down the list to locate  your service name and in the next column (labelled "Runtime Class  Name"), you will see the name of the ABAP class that implements this  service.
5. You can now look at this ABAP class in SE80

If you want to identify the metadata class that is used to define the Gateway service's interface, then proceed as follows:

1. Still in SM34, select the "Define Object Model Group" node from the tree display on the left.
2. Select the row of the table containing your external service name and double click on the "Assign Object Models to Model Groups" tree node on the left side of the display.
3. You will now see the Technical Model name. Remember this name.
4. Now, select "Define Object Model" from the tree structure on the left of the screen.
5. Locate the Technical Model Name in the first column of the table, and once found, the third column of the table will show you the ABAP class that defines the Gateway service's metadata.
6. You can now look at this ABAP class in txn SE80

Important!

Now that you've located the two ABAP classes that implement a Gateway service, you might be a little puzzled as to how they operate together.

From the perspective of the ABAP coding, there is no direct connection between the Gateway metadata class and the Gateway runtime class.

The only connection between these classes is the configuration you've just reverse engineered by looking at cluster /IWFND/VC_MGW_SG.  The association is like this:

• The metadata class is wrapped in an Object Model.
• The runtime class is wrapped in an Object Model Group.
• The Object Model (wrapping the metadata class) is then assigned to the Object Model Group (that wraps the runtime class).

So there you have it, simple really (!?)

:-)

Chris W

What Does It Mean For A Business Software Vendor To Support HTML5?<br />(Executive Summary)

Irrespective of the version you read, the purpose of this blog is to cut through all the marketing phluff and hype that has grown up around HTML5 and get down to the hard facts.

My approach focuses first on examining whether the correct question is being asked, and secondly, on the various standards and recommendations that exist for the functional capabilities of a browser.  This will act as the groundwork for establishing what HTML5 actually is.  Only then we can start to address the opening question of what it means for a software vendor to “support” HTML5.

Remember all the hype that AJAX generated 6 or so years ago?  Well, history seems to be repeating itself; but this time, the name “Ajax” has been substituted for “HTML5”.

Even though there are an increasing number of websites dedicated to showcasing and explaining what HTML5 is, the public perception of HTML5 still seems to consist of 9 parts disinformation, hype and marketing phluff, mixed with 1 part hard fact.

Extracting the HTML5 facts from the phluff will require exactly the same approach.  Once we have carefully defined the question, answering it should be very straight forward.

The most accurate description of HTML5 is to say that it is the next major revision of HTML – the language used to build web pages.  However, this description is not particularly helpful since many people do not have a clear understanding of what the term “HTML”[[1] | https://weblogs.sdn.sap.com/cs/blank/create/wlg#_ftn1] actually describes.

In addition to this, through the indiscriminate use of hype and marketing phluff, the media has expanded the term “HTML5” such that it is now little more than a generic, blanket term covering a wide range of new, Web-based features that you may (or may not) find popping up in the shiny new browser you’ve just installed.

In order to de-phluff the whole “What is HTML5?” question, we must first backtrack few steps and look at how standards for the Web are defined and who defines them.

Independently of the W3C, the WHATWG took it upon themselves to develop a major revision of the W3C’s current HTML standard known as HTML4.  This is where the term “HTML5” was first used.

Then In April 2007, the WHATWG proposed that the W3C adopt their new HTML5 proposal as the starting point for their work.  This proposal was accepted and, as of May 2007, the W3C took on WHATWG’s specification for HTML5 as their official proposal for the new HTML standard.

The W3C exists as a community of individuals, businesses, non-profit organizations, universities and government bodies who have made it their task to bring agreement to the development of software standards for the World Wide Web.  The W3C has an Advisory Committee that oversees the process of standards recommendation.

As of January 2011, the W3C had 324 members.

The W3C defines standards not only for HTML, but also for many other areas of Web based software.
These include:

As you can see, HTML is just one of many different standards defined by the W3C.

Well, let’s just say you shouldn’t hold your breath waiting.

There is a well-defined process through which all recommendations pass, starting with the initial idea and finally ending up at a formal recommendation.  These stages of maturity are as follows:

The time it takes to get an initial idea to progress through these stages of maturity varies widely and in some cases, can be quite long.  For instance the third revision of the Cascading Style Sheet standard (known as CSS Level 3 or just CSS3) started in 1998.  This standard is still being worked on in 2011![[3] | https://weblogs.sdn.sap.com/cs/blank/create/wlg#_ftn3]

Having a standards body for Web based software is all very good and necessary, but the W3C has no direct authority to enforce the adoption of any of its recommendations.  Therefore, browser vendors have implemented only those new features that best suited their development timescales and/or corporate goals.  This piece-meal approach to feature development has created a high degree of inconsistency between different browsers and has been a major source of heart-ache and pain for Web developers – just ask any Web developer how much extra time, effort and expense is required to get a website to function equally well in not just different browsers, but different versions of the same browser.

In spite of the fact that the bureaucratic processes of the W3C move like a speeding glacier, the hype and media interest surrounding HTML5, together with the fact that the Web has become a ubiquitous part of our business and social lives, has provided sufficient incentive for the major browser vendors to implement many of the new W3C features long before they ever reach even the Candidate Recommendation stage.

Consequently, the picture today for inter-browser compatibility is still not perfect, but is looking better than it has done in the past.

Back in 2008, Ian Hickson, the editor of the HTML5 specification, quipped[[4] | https://weblogs.sdn.sap.com/cs/blank/create/wlg#_ftn4] that he did not expect HTML5 to become a full W3C Recommendation before 2022.  Fortunately, he has since revised that opinion and stated that he expects HTML5 to reach the Candidate Recommendation stage in 2011, and become an official W3C Recommendation by 2014.

Writing this blog in February 2011, 2014 still seems like quite a long way off; but unlike the adoption of HTML4 and CSS2 over a decade ago, browser vendors have not waited for the W3C to give the green light; they have just gone ahead and implemented the features anyway.  This is largely because browser vendors can achieve many functional advantages through early adoption of the W3C’s proposed new features – regardless of the fact that most of the proposals are still at the Working Draft stage.

So let’s look at what HTML5 actually is and what it can offer.

As we have seen from the previous section, the W3C is currently working on multiple proposals for how Web based software should operate. These recommendations cover a wide range of functionality that includes:

These topics are just some of the many currently being dealt with by the W3C.  However, if you look at all the different features that the media are labelling as “HTML5”, you will find that they are drawn from many different W3C proposals – only one of which is actually called HTML5.

So when the term “HTML5” appears in common usage, it is typically being used simply as a generic term to cover a wide variety of new, browser based features – and not simply the single W3C standard called HTML5.

Hold on a second there, Tiger!

As stated above, browser vendors have looked at the wide range of new functionality proposed by the W3C and adopted those parts that best suited their development schedules or corporate needs.  Although the situation is better than it has been in the past, incompatibility still exists between different browsers with regard to support for the full range of “HTML5” functionality.  So the bottom line is this:

As someone who writes Web-based business applications, it probably leaves you feeling pretty annoyed at the authors of all those rave blogs and eZine articles who've told you how wonderful life will be in HTML5’s Promised Land.  So here’s how to proceed:

1. Check with your customer base and find out what browser(s) they are using.
2. Check to see which of the new “HTML5” features are supported by those browsers.
3. The list created in step 2) will then define the subset of true “HTML5” features you are free to work with.
4. Only then can you start to build an “HTML5” application that will work at your customer’s site.

The bottom line here is that you’re nowhere near the Promised Land of “HTML5” – instead, you’re wandering in the HTML4 wilderness without even having satisfactory support for CSS2.

Various websites exist that will either present you with tables of which browser supports which feature, or the website will check the capability of your particular browser and give you a simple report.  These include:

By museum piece, I really mean Internet Explorer 6, but these principles apply to any out-of-date browser.

If the customer is willing to upgrade their browsers, then you are free to use whatever HTML5 features are supported by the customer’s choice of browser.

If, however, the customer is either unwilling or unable to upgrade from their old version(s) of IE, then you can adopt one of three approaches:

In this approach, you would deliver your Web application using only those capabilities delivered by HTML4, JavaScript and CSS2.  Generally speaking your application will run successfully in both the old and new browsers; however, you should be aware that you will:

1. Accept the current limitations of HTML4 and CSS2 to be less of a problem than a browser upgrade
2. Be unable to deliver an application that provides a modern UI experience

In this approach, you attempt (as much as possible) to make your application look and function like a modern “HTML5” based application – without actually being one.  This approach is widely used at the moment by Web developers who want to make use of the benefits provided by “HTML5”, but are restricted by the limitations of browsers that do not understand the new HTML5 tags, new JavaScript functionality or CSS3 style information.

Since this approach requires that HTML5-like functionality is re-developed using old technology, a Cost/Benefit analysis is strongly recommended before embarking on such an exercise.

Unless you, the business software vendor, also write your own browser, then you are entirely reliant on the 3^rd party browser vendor to provide support for the various new “HTML5” features you wish to use.

Therefore in the above question, we should replace the word “support” with the word “implement” and also be a little more specific on what we mean by the term HTML5.  So the question now reads:

And I think you already know the answer to this question...

:-)

Chris Whealy

How to find the exact table cell on which your WD Java Context Menu was created

Right click on any cell that does not belong to the currently selected table row:

!http://whealy.com/images/Web%20Dynpro/Table_Context_Menu.gif|height=152|alt=Context Menu Visible|width=255|src=http://whealy.com/images/Web%20Dynpro/Table_Context_Menu.gif|border=0! 

Now select the "Select this cell" option and look at the message that appears in the status bar below (in this example, we clicked on the cell containing the value "C3"):

!http://whealy.com/images/Web%20Dynpro/Selection_Message.gif|height=31|alt=Selection message|width=646|src=http://whealy.com/images/Web%20Dynpro/Selection_Message.gif|border=0! 

 And there you have it!

I trust you will find this useful.

 Chris W (@LogaRhythm) 

Web Dynpro Java eLearning

As time allows, I am building up a library of eLearning presentations on Web Dynpro Java.

I have generally called these presentations the "Online Web Dynpro Training Series" and together with alot of other SDN content on the subject, form a core of information that will help you not only get started with Web Dynpro Java, but also learn to develop good coding practices right from the start.

Update to Web Dynpro Mind Map 

The Web Dynpro Mind Map has been updated to provide links into these presentations.  Please use the mind map as a tool to give you an overview of the whole topic.

From the mind map, you'll find links into many different SDN documents and eLearning presentations.

OK, so how do I find this stuff?

To find the links to these eLearning presentations, please visit the SDN Wiki page for Web Dynpro Java.  Starting from the SDN Wiki Page, the path is Web Dynpro Java -> Learning Map.

Here, you will find links to both the eLearning presentations and the latest version of the Web Dynpro Mind Map.

Have Fun!

Chris W

Web Dynpro for Java Mind Map

Introduction

What’s a Mind Map?

Anyone who’s ever had to try and make sense of a large quantity of information will know that as soon as you try to force that information into some sort of list or sequence, you often loose more than you gain. The list might look neat and tidy, but you will not have an accurate representation of the interrelationships between all the different facts.

The bottom line here is that information cannot be represented entirely sequentially or hierarchically. In reality, one piece of information is related to multiple other pieces of information to form a web of relationships, associations and dependencies.

A mind map is a simplified form of a diagram known as a Semantic Network. Mind maps have been used in many different forms for many centuries, but have lately been popularized by the British psychologist and educationalist Tony Buzan.

A mind map allows you to create a web of relationships between words, ideas and tasks. In creating this network or web of relationships, you can communicate the structure of information in a way that is compact and easy to understand. Rather than having to use several sentences of text to describe the relationship between a set of ideas, you can simply place each idea on the page and draw lines between them. The lines can additionally be labelled in order to add further description to the relationship. Typically, a mind map will start from a central topic, and from this will spread out various related topics.

When used correctly, this diagramming technique can concisely describe the relationship between multiple ideas and tasks yet require significantly fewer words than an equivalent plain text description would.

In addition to this, the associations between the information in a mind map often act as triggers to your memory, and help you remember details about that particular topic that you thought you’d forgotten.

This is why I have chosen to use a mind map to represent the ideas, facts and tasks involved in understanding Web Dynpro for Java.

Graphics and screen shots

The screen shots are taken from the Mindjet® MindManager® Viewer 7 running as a stand alone program as opposed to a browser plug-in.

How to View the Mind Map

This mind map has been created using the Mindjet software called MindManager. In order to view this mind map, you must install the Mindjet MindManager Viewer either as:

• A stand alone program
• As a browser plug-in (Only Internet Explorer v6.0 or higher)

Stand alone program installation

To install the Mindjet MindManager Viewer as a stand alone program, please follow the link to the Mindjet website where the software is available for free download (25Mb download).

The viewer software is available in four different languages (English, German, French and Japanese) for both PC and Mac systems.

Browser Plug-in

If you are using Internet Explorer version 6.0 or higher, then the plug-in will install automatically.

Depending on the security settings of your browser, you may see a security warning message displayed. Click on "Yes" to install the ActiveX plug-in.

Figure 1: Possible security warning during plug-in installation

Follow this link to view the Web Dynpro for Java mind map using the browser plug-in.

Downloading the Mind Map

If you choose to install the stand alone Mindjet MindManager Viewer, then you need to have a local copy of the mind map file. This is done by right-clicking on this link Web Dynpro mind map and select "Save Target As".

W A R N I N G !
It is possible that the browser will mistake the mind map file for a ZIP file, and then try to open it with some tool such as WinZIP or WinRAR. If this happens, you must make sure that the file extension is not changed to .zip. The mind map file must have an extension of .mmap and must not be unzipped.

Using the Web Dynpro Mind Map

General Information

Once you have installed the Mindjet MindManager Viewer as either the stand alone program or the browser plug-in, you will then be able to view and navigate around the Web Dynpro mind map.

Figure 2: The Default View for the Web Dynpro Mind Map

As you can see from Figure 2, radiating out from the central subject are nine different topics. Each one of these topics is then broken down into further sub-topics. As these branches are expanded, further relationships will emerge between the different sup-topic areas.

You will also notice from the diagram above that some of the links have icons to the right of the text. This indicates that a hypertext link is available to take you to a document, presentation or web page within either SDN, or the Online SAP Help or some other relevant information source.

Figure 3: When the same concepts appear in multiple locations within the mind map, blue association arrows link them together

Since information cannot be arranged sequentially without significant degradation, you will see the same concepts or topics appearing in multiple places across the map. When they do, you will see a blue association arrow that connects them together. See Figure 3 above.

Mind map navigation

Once you have expanded several branches of the mind map, you will find that it rapidly becomes larger than the available screen size. In this situation, you can either change the zoom level (Ctrl + spin mouse wheel) or drag the whole map around to examine a particular area.

Dragging the map can be done by first left-clicking and holding, and then the mouse pointer changes to a hand and you are then able to drag the whole map in any direction.

Be careful about expanding too many branches of this map at once! This map can grow to become very large and you will not be able to see all the branches at once. It is recommended that you expand only the particular branch you are interested in.

Figure 4: Since the mind map is very large, you should only expand the branches you are interested in.

Printing the mind map

It is quite possible to print the fully expanded Web Dynpro mind map - as long as you have a sufficiently large printer! For instance, the entire map can be printed successfully on an HP 1055CM printer. The resulting print is about 1 metre wide and 2.5 metres high.

A word of warning about the print settings though! In the Page Setup menu, always ensure that the "Print Background" option is switched off!

The reason is that the mind map has an off-white background colour defined for it. This makes it easier to read on the screen, but if you attempt to print the fully expanded mind map, it will generate a print job of around 475Mb (depending on the type of printer being used). Not surprisingly, a print job this size caused the above printer to abort the job.

The answer is simply to switch off the background colour during printing, and the size of the print job drops to just over 2Mb!

Figure 5: If you wish to print the fully expanded mind map, then ensure that the Background colour is not printed.

So why shouldn't I use a Web Dynpro Project?

The project type "Web Dynpro Project" was developed before SAP had any development infrastructure software. The drawback with this type of project is that it behaves like a sealed, non-reusable container.

Nowadays, we have the NetWeaver Development Infrastructure (NWDI) to manage source versions, build dependencies and transports. This means that unless you are writing a very simple training or demo application, you should not use a project type of "Web Dynpro Project".

OK, what should I use instead?

The answer is that you should always use Development Components (DCs) of type "Web Dynpro". Even if you do not have a working NWDI installed, you can still create Local Development objects. In the ABAP world, this is equivalent to creating objects of package (formerly Development Class) $TMP.

The point here is that a DC is a reusable entity. If you have already created a Web Dynpro Project, then for comparison purposes, it is useful to create a DC of type Web Dynpro, and then expand the first level of the project hierarchy. You will notice that the Web Dynpro Project has three nodes directly under the project branch, but the DC of type Web Dynpro has four. The extra branch is critically important. This is the "DC Metadata" branch, and it is here that you can declare both the usage dependencies to other DCs (under "DC Definition"), and those parts of your DC that will be publicly available (under "Public Parts").

How should DC's be used then?

The DC of type Web Dynpro represents a reusable unit of code. This concept gives you a high level of flexibility over how your DCs should be structured, so it is not possible for me to give any exact rules about how much code should be put into one DC. However, there are some general principles to follow:

1. A DC should be structured such that it represents a self contained unit of business processing.
2. If a DC is made too small, then you will have highly fragmented reuse situations and end up with a complex network of inter-DC dependencies.
3. On the other hand, if you make a DC too big, then you restrict its reusability because it will contain more functionality than is required for an individual reuse case.
4. DCs expose their internal functionality through the concept of Public Parts (PPs). The PP is a compiled and delivered as a separate .jar file.

When you create the Web Dynpro Components within the DC, you should decide which functionality will be publicly visible, and which will remain hidden within the DC.

When you have identified a unit of functionality (for instance, a particular component) that needs to be publicly available, you should right mouse click on that entity, and select "Add to Public Part".

If you have not created a PP before, then the first screen you will see asks you to create the PP. Give some meaningful name that describes the exposed object or functionality, and then the PP will be created and the entity added to it.

That's pretty easy. Is that all there is to it?

N O !
Remember I said that the PPs of a DC are implemented as separate .jar files? Well, the PP jar files need to be built - this is a second, independent build process from the "Rebuild Project" option that you normally use. You must therefore select "Development Component" from the right mouse click menu on the DC node, and then select "Build" from the side-menu. Only then will the PP jar file be built.

If you forget to do a DC build, then you'll probably be able to deploy your application (though without the PP jar files), but you'll experience runtime dependencies failures.

So how do I reuse this functionality?

Once you have developed a DC and built its PPs, you can then declare a usage dependency from another DC. A very useful example here is to split the model objects required by a Web Dynpro application into a separate DC. In this model DC, you create only the model objects - no Web Dynpro components. Then you add each model object to its own PP (don't forget to do a DC build each time a PP changes).

Lets say that you are now writing another DC that wishes to use one of the model objects in the model DC. So under the "DC definition" branch of "DC Metadata", you will find the "Used DCs" branch. Here is where you can add a usage declaration to the model DC. Once you have done this, when you want to add a model usage to your Web Dynpro component, you will see all the models in the model DC when you select the "Add" option from the Used Models branch (if you don't see any model objects when you select "Add", its probably because you haven't built the PPs of the model DC.

By putting the model objects into a separate DC, the model object source code only needs to be compiled once (usually a time consuming process), and then the DC that has declared a usage of the model DC only needs to reference the compiled code. This greatly speeds up development time!