19 Jun 1995 - Preliminary Information

# XSpO - External SpHyDir Rexx Code

It is nice to have code that understands Web Explorer, but other people use Netscape, Mosaic, or other browsers. SpHyDir can't handle every type of hotlist file. The solution to this and other problems is an External SpHyDir Object. These are called XSpO's (pronounced "expo") but given that they are written in Rexx, it is acceptable to roll an "R" in front of the name and call it a "Rexx-spo".

An XSpO is an external Rexx program that resides as a CMD file on disk. If you click on the file with the second mouse button, open its Settings, and change the icon, you can give it some meaninful icon. Then you put a shadow of the file in a desktop folder, probably along with your program object for SpHyDir.

An XSpO acts something like a Tool. You drag it from its workplace folder and drop it somewhere in the SpHyDir program. The nature of the XSpO decides where it can be dropped. Unlike the Tools, an XSpO could be dropped on an entry area or list.

The XSpO interface will be extended whenever an idea comes to mind. Currently, the two supported uses of an XSpO are to fill the New Links list box in the Link Manager window and to add a URL Link to an object in the work area. Sample XSpO files are supplied with SpHyDir for both purposes and will be discussed here.

SpHyDir assumes that it has an XSpO whenever the user drops a CMD file on an object. When the object accepts XSpO, it generates a Rexx Call to the file as an external procedure. Since the caller is running in the VX-Rexx environment, all of the VX-Rexx functions are available to the XSpO. However, it will be difficult to make use of them without 1) a copy of the VX-Rexx manual and 2) some hints from me about the environment. An XSpO that uses VX-Rexx function calls to manipulate objects is said to be "dirty." The internal implimentation of SpHyDir may change in the future, and such files may need to be changed. An object that supports XSpO will generally provide a convention using only arguments, the return value, and the stack. Details may differ from object to object. An XSpO that does not directly call VX-Rexx functions is said to be "clean." The terms are relative, and it may be convenient to use "quick and dirty" techniques from time to time.

When an XSpO is called, it is always passed as an argument the name of the object on which it was dropped. There is no good way (currently) for XSpO's to declare a type, so the XSpO itself has to make sure it has been dropped in the right place and return without doing anything if it is called by the wrong object. Objects that call XSpO's should ignore any null return.

When an XSpO is dropped on the New Links listbox of the Link Manager window, it is passed no arguments other than the "New_Links" object name. The XSpO puts new list entries on the Rexx stack. Each entry begins with a URL (no blanks are allowed by SpHyDir in a URL) and then a Title (blanks are OK in the tile). Each line in the Rexx queue is one list entry. Only the title will show up in the list box, the URL is kept as user data and is presented later on when the title is dragged to create a link. If the XSpO returns the word "CLEAR" from the function call, then the list box is cleared and the new list becomes its only contents. Otherwise, the new links are added in front of the existing links.

The following is the complete text of an XSpO that duplicates the existing Web Explorer Link Manager function. This file is distributed with SpHyDir and may be adapted to support other quicklist formats.

    /* XSpO version of Web Explorer Links */
    arg object
    if object<>"NEW_LINKS" then return

    exploreini=Value("ETC",,"OS2ENVIRONMENT")"\EXPLORE.INI"
    strm_status = Stream( exploreini, "Command", "Open Read" )
    if strm_status="READY:" then
        do while lines(exploreini)>0
        line=linein(exploreini)
        if line="[quicklist]" then leave
        end
        do while lines(exploreini)>0
        line=linein(exploreini)
        parse var line "quicklist=" title
        if title="" then return
        url=linein(exploreini)
        queue url title
        end
    return "CLEAR"

The Workarea also supports XSpO's, but the only function currently supported is to add a Link to an object. Dropping this type of XSpO on a Workarea object is simpler than adding the link to the Link Manager list and then dragging the list item over and dropping it on the object. A supplied XSpO uses some rather "dirty" logic to find the current URL in Web Explorer (you have to enable the WE option that displays the URL in a box at the top of the window). Dropping this XSpO on a paragraph, point, or image puts a link to whatever page is currently being displayed in WE (without requiring that the page be added to the Quicklist).

    arg object
        if wordpos(object, "NEW_LINKS WORKAREA")=0 then return

        desktop = "?HWND1"
        app = VRGet( desktop, "FirstChild" )
            do while app<>""
            title=VRGet(app,"Caption")
            if substr(title,1,16 )="IBM WebExplorer " then
                do
                title=strip(substr(title,19),"B")
                kid= VRGet(app,"FirstChild")
                url=Searcher(kid)
                if url<>"" then queue url title
    	 if object="WORKAREA" then return "LINK"
                return "ADD"
                end
            app = VRGet( app, "Sibling" )
            end
    return ""

    Searcher: procedure
        parse arg w
        do while w <> ""
            if VRGet( w, "Visible" ) = 1 then do
                class = VRGet( w, "ClassName" )
                caption = VRGet( w, "Caption" )
                if class="WC_ENTRYFIELD" then return caption
                subkid = VRGet( w, "FirstChild" )
                url= searcher(subkid)
                if url<>"" then return url
                end
            w = VRGet( w, "Sibling" )
        end

    return ""

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Copyright 1995 PCLT -- SpHyDir Web Document Manager -- H. Gilbert
May be distributed with SpHyDir program

This document generated by SpHyDir, another fine product of PC Lube and Tune.