Compiled by DevEdge Champions Alex Mann and Kevin Hecht.

• Alex Mann is a systems engineer with a master's degree in computer science from Columbia University in New York.
• Kevin Hecht is a business student at Villanova University in Philadelphia, majoring in accounting and management information systems. He specializes in general browser client issues and administration, user interfaces, and general intranet solutions.

If you have additional questions about Communicator, visit the Client Technical Discussion Group. Please don't contact Champions directly with questions until you've first posted the issue to the discussion group and allowed several days for a reply.

Last Updated: 2/00

Section 1: General Client Information

Section 2: Basic Concepts and Operations

Section 3: Messenger

Section 4: Client Preferences

Section 5: DDE and External Applications

Section 6: Plug-ins and Extending the Client

1. Which questions are appropriate for the Client Technical Discussion Group?
2. What is Netscape client software?
3. What is the Netscape Everywhere Standard Browser Distribution Program?
4. Why did Netscape decide to make Communicator 5.0 source code freely available?
5. Which platforms are supported in Netscape Communicator?
6. What is Netscape Netcaster (aka Constellation)?
7. What is SmartUpdate?
8. Does Netscape client software support IMAP?
9. Does Netscape client software support LDAP?
10. Does Netscape client software support IIOP?
11. How does Netscape client software support vCard?
12. Does Navigator support style sheets?
13. Does Navigator support the <OBJECT> tag?
14. Which image formats does Navigator support?
15. Which protocols does Navigator recognize?  

The Client Technical Discussion Group is the proper place for discussion of issues concerning Netscape client software such as Netscape Navigator and Netscape Communicator. In general, questions asked in our discussion group pertain to "big picture" issues such as future capabilities of client software and the ability to extend Netscape Communicator components such as Composer and Navigator. Although our group isn't as heavily used as some of the more popular DevEdge discussion groups, it's a valuable resource for many questions that don't seem to fit elsewhere. For Netscape Netcaster issues, please use the Netcaster Discussion Group. For issues pertaining to JavaScript, please use the JavaScript Newsgroup. Plug-in developers with specific questions about plug-ins should use the Plug-ins Discussion Group.

1.2. What is Netscape client software?

Netscape client software is software that runs on the client. Communicator, available in both professional and standard editions, is the flagship of Netscape's client software. Communicator combines Netscape Navigator, the world's most popular browser, with a suite of Internet tools for high-performance Internet mail, web page creation, and instant messaging. Additionally, Netscape client software includes Navigator plug-ins such as LiveAudio and LiveVideo.

1.3. What is the Netscape Everywhere Standard Browser Distribution Program?

The Netscape Everywhere Standard Browser Distribution Program allows participants to distribute Netscape Navigator and Netscape Communicator Standard Edition to their customers and prospects with no licensing fees. An online application and agreement allows participants to download multiple versions of Communicator and Navigator simply and easily. The distribution program allows participants maximum flexibility in deciding how, where, and when to distribute these world-class Netscape client products. For more information, refer to the Standard Browser Distribution Program FAQ.

1.4. Why did Netscape decide to make Communicator 5.0 source code freely available?

On January 22, 1998, Netscape announced that Netscape Communicator Standard Edition 5.0 source code would be freely available for modification and redistribution. Netscape believes that harnessing the creative abilities of all Internet developers will be an unprecedented way to advance the features and quality of Netscape Communicator for all customers. Detailed license terms, additional information, and a developer release of Netscape Communicator Standard Edition 5.0 source code are available from mozilla.org. For more information, refer to the Netscape Communicator Source Code FAQ.

1.5. Which platforms are supported in Netscape Communicator?

Communicator is cross-platform client software, which means it works on many different platforms, whether Windows, Macintosh or Unix-based. Communicator supports the following platforms:

• Windows 98
• Windows 95
• Windows NT 4.0
• Windows NT 3.51
• Mac OS 7.6.1 and 8.5 for PowerPC
• Unix: Sun Solaris 2.5.1 and 2.6
• Unix: Solaris x86 2.5.1 and 2.6
• Unix: Silicon Graphics IRIX 6.2, 6.3, 6.4, and 6.5
• Unix: IBM AIX 4.2
• Unix: HP-UX 10.20 and 11.0
• Unix: RedHat 5.2
• Unix: DEC Digital 4.0b

Although not supported by Netscape, Communicator and Navigator are available for the following additional platforms:

• Open VMS
• Unix: Apple MKLinux 2.1
• BDSI 3.0 and 3.1
• BlackLinux
• DEC Digital 3.2 and 4.0
• FreeBSD 2.2
• Linux PPC
• NCR MP-RAS 3.0
• NEC EWS-UX 4.2
• NEC 9800
• NeXTStep 3.3
• Red Hat AlphaLinux 4.2
• SCO Gemini 1.0
• SCO OpenServer 5.0.4
• SCO Unixware 2.1.2
• SINIX 5.42
• Sony NEWS
• SparcLinux
• SunOS 4.1.3
• UltraLinux

1.6. What is Netscape Netcaster (aka Constellation)?

Netscape Netcaster is the powerful "push" component of Netscape Communicator that lets you customize, focus, and automatically receive the information you care about. Built entirely as a crossware application, Netcaster enables delivery of two types of channels - web server channels based on Dynamic HTML, and Marimba Castanet-based channels. Netcaster was first announced under the code name "Constellation."

1.7. What is SmartUpdate?

SmartUpdate is a set of technologies that enable software to be installed in a secure manner using Netscape Communicator as a front end. Although any software can be installed using SmartUpdate, it's ideal for installing Navigator plug-ins and Java classes. To find out how to enable your software for SmartUpdate, read the technote Tips and Techniques in Smart-update Enabling Software. For an introduction to SmartUpdate, see the SmartUpdate Developer's Guide.

1.8. Does Netscape client software support IMAP?

Messenger, a component of Communicator, supports the Internet Message Access Protocol (IMAP). IMAP allows users to maintain remote folders, increases flexibility in checking mail, and improves management of offline messaging. Of course, any IMAP client needs an IMAP-enabled server, such as Netscape Messaging Server. The article Message Access Paradigms and Protocols explains why IMAP is better than the Post Office Protocol (POP).

1.9. Does Netscape client software support LDAP?

Communicator supports the Lightweight Directory Access Protocol (LDAP) throughout its various components. In addition to maintaining "address books," LDAP is a valuable feature for integration with Conference and Calendar components. Of course, LDAP client software must connect to an LDAP server, such as Netscape Directory Server. If you need a publicly accessible LDAP server for testing purposes, several of the larger "people finders" on the Internet have such servers online now.

1.10. Does Netscape client software support IIOP?

Internet Inter-ORB Protocol (IIOP) is a standard for facilitating communication between objects, as defined by the Object Management Group. Netscape expects that during the next few years IIOP will become as ubiquitous as HTTP and CGI, which are supported in Navigator 4.0 and later. Support for IIOP will come through additions to the Internet Foundation Classes (IFC) for Java developers. The object request broker technology comes from Inprise/Borland through their VisiBroker technology. For questions pertaining to IFC, please use the IFC Discussion Group.

1.11. How does Netscape client software support vCard?

A vCard is a digital representation of a business card. Netscape Communicator supports vCard technology by allowing users to distribute their vCards, as well as use vCards for easy information entry into the Address Book. Originally developed by the Versit Consortium, vCard technology is now a standard maintained by the Internet Mail Consortium (IMC).

1.12. Does Navigator support style sheets?

Netscape Navigator 4.0 and later support CSS-1 (for control of styles), CSS-P (for absolute positioning), and the W3C Document Object Model (for animation and drag and drop) via JavaScript.

1.13. Does Navigator support the <OBJECT> tag?

Navigator 4.0 and later support the <OBJECT> tag as defined in the current W3C working draft. The tag allows insertion of objects such as (but not limited to) images, signed JavaScript JAR files, Java applets, and multimedia files. For information about using the <OBJECT> tag with plug-ins, see the Plug-in Guide.

1.14. Which image formats does Navigator support?

Currently, Navigator supports gif87 and gif89a formats, as well as JPEG and progressive JPEG. Animations and interlacing are made possible through support of the gif89a specification. Navigator 4.04 and later now natively support the new PNG format (which has a reference specification available), although it lacks alpha channel support.

1.15. Which protocols does Navigator recognize?

The following list summarizes known protocols that Netscape client software either currently uses, once used, or will someday use:

• http:// (Hypertext Transfer Protocol)
• https:// (Hypertext Transfer Protocol via SSL)
• ftp:// (File Transfer Protocol)
• news:// (NNTP Protocol)
• snews:// (for NNTP postings via SSL)
• news: (for using the default news server)
• ldap:// (Lightweight Directory Access Protocol)
• gopher:// (the old Gopher hypertext stuff)
• telnet:// (launches a Telnet helper application, if installed)
• javascript: (executes JavaScript statements)
• mocha: (executes JavaScript statements)
• pop3:// (Post Office Protocol)
• addbook: (to add vCard entries to Communicator's Address Book)
• about: (internal URLs, Easter Eggs, employee home pages, and various other pages and images)
• castanet: (Castanet Tuner URLs for Netcaster)
• file:// (local file system access)
• mailbox: (mail folder access)
• imap:// (Internet Message Access Protocol)

There may well be other prefixes that aren't listed here. If you have a specific question about this, post it to the Client Technical Discussion Group.

Back to the Question Summary, or to the top.

1. I've tried using layers in Communicator, but what about style-sheet layout?
2. How can I support multiple users on one copy of Communicator?
3. What is location independence, and how does Communicator support it?
4. How can multiple employees share a commonly accessible address book?
5. How can I upload files via FTP using Navigator?
6. What is Navigator's "cache" and how should I manage it?
7. How can I force a web page not to be cached on the client?
8. Why do I sometimes get a "data missing" error?
9. What are cookies, and how do I use them to maintain state?
10. What is the Open Profiling Standard (OPS)?
11. What is canvas mode?
12. How can I suppress the dotted line that appears around selected linked images?
13. How can I remove the single-pixel border from frames?
14. How can I keep others from using my personal certificates in Navigator?
15. What software is available to digitally sign scripts and applets?
16. Can I use Navigator/Communicator as an ActiveX control?
17. Can I launch Netscape Composer from HTML or JavaScript?

When creating Communicator, Netscape answered customers' need for absolute positioning capabilities by introducing dynamic layers. In collaboration with the World Wide Web Consortium, Netscape and Microsoft later authored a specification to extend style sheets to include positioning capabilities. Netscape will support both methods of positioning for the foreseeable future.

2.2. How can I support multiple users on one copy of Communicator?

Multiple users can share the same copy of Communicator on any given machine through the technology of profiles. You can use profiles to toggle between multiple user preference settings upon startup of Communicator. Profiles keep user settings such as email address, name, and certificates, as well as mail and news folders and cache files. Use the Netscape User Profile Manager to keep track of your various user profiles.

2.3. What is location independence, and how does Communicator support it?

Location independence means that multiple users can share the same copy of Communicator regardless of where their machine is in a network. Communicator 4.5 introduced support for this by providing roaming access for profiles using an HTTP or LDAP server. Using Mission Control Desktop 4.5, installers for network servers can also be created.

2.4. How can multiple employees share a commonly accessible address book?

Any LDAP-based directory server can be used by Communicator for this purpose. Currently, the best solution for this is Netscape Directory Server.

2.5. How can I upload files via FTP using Navigator?

Navigator provides a couple of different mechanisms for uploading files via File Transfer Protocol (FTP).

Once logged onto an FTP server anonymously, a user can simply drag and drop files into the Netscape document window to upload them. A prompt will appear asking the user if she wants to upload the files.

A user can also log onto an FTP server using a username and password. Assemble the URL like this:

ftp://username:password@ftp.whatever-host.com/

Be careful using this method; you might want to omit the password (Navigator will prompt you for it) so that the complete URL doesn't appear in Navigator's global history file.

2.6. What is Navigator's "cache" and how should I manage it?

A "cache" (pronounced like "cash") temporarily stores information on your computer from web pages you've visited. If you later revisit a page that's stored in the cache, Navigator can retrieve the page from its cache more quickly than retrieving the page again from a location out on the network. More information on managing your cache is available in the technote Caching, the Cache Directory, and .moz Files. Background information is also available in the Navigator Handbook. Note that Netcaster, a Communicator component, maintains its own cache independent of Navigator. IS administrators can control the size of all of the client software cache files through Netscape Mission Control Desktop.

2.7. How can I force a web page not to be cached on the client?

By using the <META HTTP-EQUIV="Pragma" CONTENT="no-cache"> tag inside the <HEAD> tag of your HTML page.

2.8. Why do I sometimes get a "data missing" error?

With some pages, whenever the user tries to print, reload, resize, or view the source of the page, she gets the following error:

Data Missing
This document resulted from a POST operation and has expired 
from the cache. If you wish you can repost the form data to 
recreate the document by pressing the reload button.

This happens if the document is dynamically generated in response to the POST data and if it contains the "Pragma," "No-cache" header/metatag. In this case, the file won't be in the cache so the browser won't be able to access the page again (either from the local cache or from the server) when the user tries to print, reload, resize, or view the page source.

 

2.9. What are cookies, and how do I use them to maintain state?

When Netscape created cookie technology, it provided an immediate answer to the problem of maintaining state across sessions in client-server communication. Cookies are a general mechanism that can both store and retrieve information on the client side of the connection. The addition of a simple, persistent, client-side state significantly extends the capabilities of web-based client-server applications. See Netscape's cookie spec and Danny Goodman's View Source article on how to set and retrieve cookies through JavaScript.

2.10. What is the Open Profiling Standard (OPS)?

Cookies have also been used to track data such as names, email addresses, or interests, based on information that users enter at web sites. In an effort to extend capabilties to support that functionality as well as satisfy the concerns of privacy advocates, Netscape, Verisign, and Firefly have proposed the Open Profiling Standard (OPS). With support from more than sixty independent companies and organizations, OPS will provide Internet site developers with a uniform architecture for leveraging personal profile information to offer individuals content, goods, and services that match their personal preferences while protecting their privacy. OPS has been submitted to the W3C for consideration as a standard.

2.11. What is canvas mode?

Netscape Communicator's enhanced canvas mode enables Netscape Navigator 4.x to display pages without any browser toolbars, menus, or borders. This feature allows developers to create kiosk applications like those already found in malls and airports and to design pages that immerse and guide the user.

2.12. How can I suppress the dotted line that appears around selected linked images?

You can eliminate the dotted line that appears around linked images when they're selected by placing the SUPPRESS=TRUE attribute in your <A HREF=/old?u=http%3A%2F%2Fdeveloper.iplanet.com%2Fsupport%2Ffaqs%2Fchampions%2F...%26gt&y=1999 tags. This feature was introduced in Communicator PR3 and won't function in earlier beta releases of the software.

2.13. How can I remove the single-pixel border from frames?

To do this, you need to add the marginwidth=0 and marginheight=0 attributes to the body element in your page. For more information, see the technote Removing Navigator's One Pixel Border.

2.14. How can I keep others from using my personal certificates in Navigator?

Personal certificates are digitally signed identification cards most commonly used on full-service Intranets utilizing a certificate server. Navigator allows you to password-protect your certificates, so that whenever they're requested you must enter a password to use them. You'll find this option by clicking the Security button to launch the Security dialog and then choosing "Passwords" in the resulting menu.

2.15. What software is available to digitally sign scripts and applets?

Netscape Signing Tool 1.3, a tool that enables you to sign JavaScript scripts, Java applets, plug-ins, and other files. This stand-alone command-line tool creates digital signatures and uses the Java Archive (JAR) format to associate them with files in a directory. It's intended for use by system administrators and by developers who want to distribute software electronically over the Internet.

2.16. Can I use Navigator/Communicator as an ActiveX control?

No, at present you can't use Navigator or Communicator as an ActiveX control. There's a project under way to create an ActiveX wrapper for NGLayout, Netscape's New Generation Layout.

2.17. Can I launch Netscape Composer from HTML or JavaScript?

No, at this moment it's not possible to launch Netscape Composer through JavaScript or HTML.

Back to the Question Summary, or to the top.

1. How can I migrate from legacy mail systems (cc:Mail, Eudora, Notes, Exchange, IBMPROFS) to Netscape Communicator?
2. What format does Netscape Messenger store email in locally?
3. Is it possible to extend the capabilities of Messenger?
4. How can I launch the message composition window and populate fields like CC: or Subject:?
5. Is there a way to start Messenger through a hyperlink in the browser?
6. Can I synchronize my address book and mail with my Palm Pilot?
7. How do I get rid of the "Welcome to Netscape Messenger" page that appears every time I start Messenger 4.5?

Netscape Communicator provides a mail client called Messenger that uses open standards to deliver rich email. To help those who may be migrating to Messenger from legacy messaging systems founded on proprietary technology such as cc:Mail, Eudora, Notes, Exchange, or IBMPROFS, Netscape provides Netscape Migration Toolkit 2.0. There's a discussion group for comments on this tool.

3.2. What format does Netscape Messenger store email in locally?

Mail is stored in a standard text file conforming to the Unix mbox format, which is simply plain ASCII text with mail body and header information. Messages encrypted with S/MIME are stored locally in encrypted form (although the headers remain in clear text).

3.3. Is it possible to extend the capabilities of Messenger?

Because Messenger makes use of Composer, the HTML-editing component of Communicator, message composition windows can hold Composer plug-ins (see the Composer Plug-in Guide for more information). However, there's no specific API in place for extending the mail and discussion features of Messenger and Collabra.

3.4. How can I launch the message composition window and populate fields like CC: or Subject:?

Most folks are familiar with links containing an HREF beginning with mailto: that launch a message composition window. It's possible to specify in such a link information such as destination newsgroups for the message, the subject of the message, cc and bcc recipients, and more. For a complete overview of how to compose these types of mailto: links, read Unleashing the Power of mailto URLs (Robert Husted / View Source).

3.5. Is there a way to start Messenger through a hyperlink in the browser?

The simplest way to start Messenger is

Open Messenger

In Navigator 2.0 and 3.0,

• mailbox:pathname refers to the folder itself.
• mailbox:pathname?id=xxx refers to a message by ID.
• mailbox:pathname?number=n refers to a message by number (the first message in the folder is 0, the second message is 1, etc.).
• mailbox:pathname?id=xxx=n is the same as the number=n form if and only if message N has the ID xxx; otherwise, it's the same as the id=xxx form. (This is for distinguishing between two messages with the same ID.)

4.0 broke this, making both the ID and number parameters mandatory; changing the number parameter from a message number to a byte offset; and making it impossible to refer to arbitrary files as mailboxes (you can only refer to files that are under your mail directory).

3.6. Can I synchronize my address book and mail with my Palm Pilot?

Yes, with Netscape Communicator 4.5 you can synchronize your mail and address book with your Palm Pilot.

3.7. How do I get rid of the "Welcome to Netscape Messenger" page that appears every time I start Messenger 4.5?

You can either disable the Messenger start page or change the URL that it loads.

To disable it:

1. Exit Netscape Communicator.
2. Open Windows Explorer and go to your ...\Netscape\Users\{username}\ directory.
3. Find the file named prefs.js and make a backup copy.
4. Use Notepad or another text editor to open prefs.js.
5. Add the following on a line of its own:

   user_pref("mailnews.start_page.enabled", false);

6. Verify that the line is exactly as shown above. Errors will prevent this from working and may result in a corrupted prefs.js file.
7. Close the text editor and save changes.
8. Restart Communicator.

To change the URL:

1. Follow steps 1-4 above.
2. Add the following on a line of its own:

   user_pref("mailnews.start_page.url", "http://home.netscape.com/");

   Replace http://home.netscape.com/ with the full URL you want to use instead.

3. Verify that the line is exactly as shown above, with the URL you want to use in quotes. Errors will prevent this from working and may result in a corrupted prefs.js file.
4. Close the text editor and save changes.
5. Restart Communicator. 

Back to the Question Summary, or to the top.

1. How can I change Navigator's default home page?
2. Is it possible to change mail preferences on the client programmatically?
3. What is the prefs.js file and how can I modify it?

To change the default page that's loaded at start-up in Navigator, modify your general preferences. In Navigator 3, choose Options / General Preferences / Appearance. In Communicator, choose Edit / Preferences / General Preferences / Appearance. For developers who are frequently running a different version of Navigator, it can be very helpful to set your home page location to About:, which will display version information in place of your default home page.

4.2. Is it possible to change mail preferences on the client programmatically?

You can change any Communicator preference setting with proper security permissions. All preferences are exposed to JavaScript. Essentially, your signed script might do something like this:

function GetNetscapePref(prefKey, defaultValue, warn) { var pref; netscape.security.PrivilegeManager.enablePrivilege("UniversalPreferencesRead"); pref = navigator.preference(prefKey); if ((!pref) || (pref == null)) { if (warn) alert(getLocalString("The preference") + prefKey + getLocalString(" is missing from your preferences file and a default value has been used. Please contact your administrator.")); pref = defaultValue; } return pref; }

4.3. What is the prefs.js file and how can I modify it?

Communicator's preferences are stored in the prefs.js file (the Netscape Preferences file on the Macintosh). You can modify this file locally as a text file or using a signed JavaScript script with the proper privileges enabled. 

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1. How can I control Navigator from my Windows application?
2. How can I control Navigator from my Macintosh application?
3. How can I control Navigator from my Unix application?
4. A helper application I've developed works locally but not over the network. What's happening?
5. How do I use WWW_OpenURL to open a URL in a frame?
6. Can I post form data to a local application?
7. Can I restrict user access to approved URLs only?

You can control Navigator from another application through the Netscape Client API (NCAPI) utilizing a platform-specific method of interprocess communication (IPC). On the Windows platform, this is accomplished through both DDE support and OLE2 automation.

5.2. How can I control Navigator from my Macintosh application?

You can control Navigator from another application through the Netscape Client API (NCAPI) utilizing a platform-specific method of interprocess communication (IPC). On the Mac OS platform, this is accomplished through Apple events. Netscape announced in 1997 that it would support the next generation Apple operating system in Netscape client software.

5.3. How can I control Navigator from my Unix application?

You can control Navigator from another application through the Netscape Client API (NCAPI) utilizing a platform-specific method of interprocess communication (IPC). On Unix platforms, this is accomplished through X properties.

5.4. A helper application I've developed works locally but not over the network. What's happening?

Frequently, developers create helper applications that seem to work fine when tested locally but that fail to launch when content is downloaded through a web server. This is the result of incorrect configuration on the server end. In this scenario, the web server is unaware of the MIME type it should associate with the file extension in question, so it defaults to the fallback MIME time (normally text/plain). To avert this problem, add the MIME type to your web server.

5.5. How do I use WWW_OpenURL to open a URL in a frame?

To load a URL into a particular frame, first get all the available window IDs by calling WWW_ListWindows. Next, get the window ID for the desired frame. WWW_GetWindowInfo will give the URL, the title, and the frame name for the specified window ID. Get this information for each of the window IDs on the list and use it to choose the window ID of the frame that you want to load the URL into. Use this window ID with WWW_OpenURL to load the URL.

5.6. Can I post form data to a local application?

Yes. This is possible with NCAPI OLE/DDE. Register the protocol (say "local") with DDE/OLE calls. Specify this protocol in your html file <FORM> tag as:

<FORM ACTION="local://Information" METHOD=POST name=form1>

After submission of the form, this will invoke the appropriate DDE/OLE server and call its function with the data along with the URL.

5.7. Can I restrict user access to approved URLs only?

Yes. One way is by registering all the protocols (http, ftp, ...) to the external application using the NCAPI OLE/DDE RegisterProtocol calls. When the user tries to access the page, your application gets the URL and filters it; if the URL is allowed, then you unregister the protocol temporarily and use WWW_OpenURL to access the data. There might be some practical problems in choosing the appropriate method. OLE doesn't provide any method to unregister the protocol; instead, you need to use registry calls to delete it from the registry. With DDE, the DDE server should be running or else the browser will allow the access.

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1. How do I build plug-ins for Netscape Navigator?
2. Are there any improvements to the Plug-in API in Communicator?
3. Can I register my own protocol with Navigator?
4. How can I extend the capabilities of Composer?
5. Can I make additions to the Navigator menu and toolbar?
6. Can I modify Navigator to lock out certain features?
7. How can I add features such as Excite Direct to Navigator's user interface?
8. Where can I get the current user profile?
9. How can I launch the default browser from an external Windows application?

The Netscape Plug-in API allows third parties to extend the Navigator component of Netscape Communicator with native support for new data types and additional features. Plug-ins appear as additional capabilities of the Netscape client, indistinguishable to the user from the baseline features. LiveConnect allows plug-ins to be controlled by Java and JavaScript. You'll find the latest Netscape plug-in documentation in the Plug-in Guide, which has been updated and expanded for Communicator 4.0. For information about using LiveConnect, or about LiveConnect-related Java or JavaScript commands, see LiveConnecting Plug-ins with Java. Netscape also makes available the Plug-in SDK and plug-in resources. Those interested in building plug-ins for Netscape Communicator should see the next question, which explains improvements to the Plug-in API in Communicator. Developers can also build plug-ins for the Communicator components Conference and Composer.

6.2. Are there any improvements to the Plug-in API in Communicator?

Communicator introduces powerful new features to plug-ins, allowing for windowless plug-ins and a way to auto-install plug-in components. For more information, see the Communicator 4.0 Plug-in Guide.

6.3. Can I register my own protocol with Navigator?

You can use NCAPI to register your own protocol. For instance, if you want to have all calls to mySuperProtocol: handled by your application, you should use NCAPI methods to get that functionality. However, it's not possible to register a viewer protocol on the Unix platform releases of Navigator.

6.4. How can I extend the capabilities of Composer?

You can extend the capabilities of Composer with a Composer plug-in. Composer plug-ins are Java classes that add more HTML-editing functionality to Composer. For more details, see the Composer Plug-in Guide.

6.5. Can I make additions to the Navigator menu and toolbar?

Navigator 4.0 supports canvas mode, which enables you to define your own interface. For special customization outside of the realm mentioned, the free Netscape Client Customization Kit (CCK) gives you access to special undocumented hooks in Netscape client software.

6.6. Can I modify Navigator to lock out certain features?

You can lock out certain features such as Java and JavaScript to Navigator users through Netscape Mission Control Desktop (formerly known as the Administration Kit). To block out access to certain web sites, use of a proxy server is recommended. In addition to Mission Control Desktop, the free Netscape Client Customization Kit (CCK) allows browser customization, but Mission Control Desktop allows remote administration of clients.

6.7. How can I add features such as Excite Direct to Navigator's user interface?

You can extend the user interface of Navigator beyond what's possible with Mission Control Desktop through the free Netscape Client Customization Kit (CCK). This kit gives developers low-level access to the Navigator code, permitting the addition of functionality similar to that in Excite Direct, which places a search field in the Navigator chrome.

6.8. Where can I get the current user profile?

This information is stored in the registry. The current user name will be available at the key HKEY_LOCAL_MACHINE/SOFTWARE/Netscape/NetscapeNavigator/Users with the name CurrentUser. External applications can access this information using the registry function RegQueryValEx().

6.9. How can I launch the default browser from an external Windows application?

The simplest and best way to launch the default browser is by using ShellExecute() and specifying a URL in the lpFile parameter. This avoids the need to search for the default browser and its location in the registry. For example:

ShellExecute(hWnd, NULL, "http://www.netscape.com", "", "",SW_SHOWNORMAL);

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Content contributed voluntarily by our awesome DevEdge Champions based on peer-to-peer discussion in the DevEdge newsgroups. While Netscape hosts them, it does not offer any direct developer support via the newsgroups.

This FAQ is intended as a developer resource. Any reference to third parties or third-party products should not be construed as an endorsement by Netscape Communications Corporation.

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