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HTML Connect User's Guide
CHAPTER 1
Welcome to the Connect for HTML User's Guide. This Guide is a companion to the exteNd Composer User's Guide, which details how to use all the features of Composer, except the Connect Component Editors. So if you haven't looked at the User's Guide yet, please familiarize yourself with it before using this Guide.
Novell exteNd Composer provides separate Component Editors for each Connect, like HTML. The special features of each component editor are described in separate Guides like this one.
If you have been using exteNd Composer, and are familiar with the core component editor, the XML Map Component Editor, then this Guide should get you started with the HTML Component Editor.
Before you can begin working with the HTML Connect you must have installed it into your existing exteNd Composer. Likewise, before you can run any Services built with this Connect in the Composer Enterprise Server environment, you must have already installed the Server side software for this Connect into Composer Enterprise Server.
NOTE: To be successful with this Component Editor, you must be familiar with the HTML environment and the applications that you want to XML-enable.
Novell exteNd Composer is built upon a simple hub and spoke architecture. The hub is a robust XML transformation engine that accepts requests via XML documents, performs transformation processes on those documents (with or without the participation of other XML-enabled services), and returns an XML response document. The spokes, or Connects, are plug-in modules that "XML-enable" sources of data that are not XML aware, bringing their data into the hub for processing as XML. These data sources can be anything from legacy applications to Message Queues to HTML pages, as shown below.
Composer Connects can be categorized by the integration strategy each one employs to XML enable an information source. The integration strategies are a reflection of the major divisions used in modern systems designs for Internet-based computing architectures. (See illustration below.) Depending on your B2B needs and the architecture of your legacy applications, Novell exteNd can integrate your business systems at the User Interface, Program Logic, or Data levels.
Composer's HTML Connect allows you to record navigation and interactions with standard Web Sites using the User Interface integration strategy by hooking into the HTML information stream (like a browser does) for later playback as a B2B service. The term HTML (Hyper Text Markup Language) is used for documents published on the World Wide Web. The HTML Connect uses a utility called Tidy which transforms hard to read and often syntactically incorrect HTML information into a clearly layered XHTML document.
NOTE: The HTML Connect does not process Flash, applets, nor ActiveX controls. JavaScript is supported: see discussion further below.
Much like the XML Map component, the HTML Component is designed to map, transform, and transfer data between two different XML templates (i.e., request and response XML documents). However, it is specialized to make a connection to an Internet or Extranet application as viewed by a web page, process the data using elements from a DOM, and then map the results to an output DOM. You can then act upon the output DOM in any way that makes sense for your integration application.
An HTML Component can perform simple data manipulations, such as mapping and transferring data from an XML document into an HTML form, or perform "screen scraping" of an HTML transaction, putting the data into an XML document. The HTML Component has all the functionality of the XML Map component and can process XSL, send mail, and post and receive XML documents using the HTTP protocol.
The HTML Connect is capable of providing secure connections between exteNd Composer and the target Web Site. This security is accomplished by using Secure Socket Layer Support 3 (SSL.3) Composer supports both client and server side digital certificates. The HTML Connect uses the HTTP Basic Authentication connection resource type to set up the security to interact with sites on the internet. The SSL protocol allows for authenticated and encrypted communication between the browser and server. To enable this security, the Composer application must have access to, and be able to process the digital certificates required by, the target web site. This means that these certificates must be installed on the your web server (Novell, Jakarta Tomcat, WebLogic, or Websphere) as well as in the HTML Connect. To accomplish this, Composer provides two methods. For server-side certificates, the HTML Connect ships with approximately 100 industry-standard digital certificates in the jar file agrootca.jar, located in the Designer/lib directory.
If you need to add a server-side certificate that is not included, refer to the documentation provided with your application server on how to maintain certificates. Also refer to the appendix for a list of certificates that are supported and how to add a new server-side certificate in Composer. For client-side certificates, Composer supports DER encoded binary x509 certificates. To associate the certificate, Composer allows you to specify the certificate in the HTTP Basic Authentication connection resource.
The HTML Component Editor supports only the HTTP/S protocol. URLs that use file://, ldap://, ftp://, or other schemes are not honored.
NOTE: The file:// protocol is supported by Composer's URL/File Read and URL/File Write actions (which can be used in any kind of component, not just HTML). Consult the chapter on Advanced Actions in the Composer User's Guide for more information.
A cookie is a text file that gets stored by the browser. One main purpose of cookies is to identify the user (the HTTP client) to the host: for instance, to maintain log-on status when moving from page to page in a website, or to maintain the current session while shopping using a shopping cart on a website. Cookies are general mechanisms which server side connections can use to both store and retrieve information on the client side of the connection. There are two types of cookies: session cookies that are active only for the duration of the session and persistent cookies that are kept on disk in the computer and are available each time you access that site.
The HTML Connect supports session cookies. This means that if required by a site, the HTML Connect will create a cookie for the time that the component is active. The cookie will be set once and then go away when the component finishes executing. During testing, the restart of animation or the execution of the component will discard any cookies before execution begins, as each execution of the component is treated as a new session. Cookie persistence is not supported.
This version of the HTML Connect supports pages with frames. The HTMLScreenDoc will contain a DOM for a loaded page. When you click on the HTML panel or drag and drop information into the input controls of one of the frames, the HTMLScreenDoc will display a DOM for this frame. If the frame is to be changed at this time, a new SetFrame action is created and recorded in the Map Action.
The HTML Connect supports JavaScript in web pages, to the extent necessary to process "redirects" and capture your design-time interactions with forms and form widgets so that you can work with scripted pages in the HTML Component Editor in seamless fashion.
There are certain limitations to JavaScript support in the HTML Component Editor. The limitations are mainly rendering-related. For example, you will not see button-rollover effects, and it's possible you will not be able to use a page that relies heavily on JavaScript-powered CSS or "DHTML" effects. In many cases, pages will look different in the component editor's native environmental panel than in your regular web browser, but you will still be able to "record" your interactions with the page so as to capture the kinds of data you need and/or map your own data into a webform. The only way to know for sure is to try working with a particular web page.
Another thing to be aware of is that many web-page authors choose to use nonstandard, browser-specific JavaScript extensions that a standards-strict HTML client will not be able to understand. Because there are so many possible permutations of browser version, language version, HTML and DOM versions, nonstandard language extensions, nonstandard vendor implementations of standards-based language extensions, etc., it is impossible to predict whether a given web page's scripts will execute properly in Composer's HTML Component Editor, without testing.
NOTE: Many web sites, especially those with mission-critical webforms, offer non-JavaScript versions of their pages for use by customers who either have older browsers or have chosen to turn JavaScript off. When this is the case, you should use the non-JavaScript version of the web site (or web page) when building your components.
The HTML User Interface Component Editor allows the extension of any XML integration you are building to include any of your business applications that require HTML-based interactions (See exteNd Composer User's Guide for more information.) For example, you may have an application that retrieves a product's description, picture, price, and inventory from regularly updated databases and displays it on a Web browser. By using the HTML Component Editor, you can now get the current product information from the website and the static information (e.g., the picture) from the database and merge the information from these separate information sources before displaying it to a user. This provides the same up-to-date information to both your internal and external users.
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