Proper file transclusion for classic JScript

Question

I want to have something like C's #include directive or Python's import() function. I would appreciate it if you consider that this is not a Javascript, VBScript, nor a JScript.Net question. I want the functionality in the JScript .js files run by cscript.exe/wscript.exe. Not the JScript/JavaScript in HTA's run by mshta.exe. The closest thing I could find so far is from here:

function Include(jsFile) {
    var fso, f, s;
    fso = new ActiveXObject("Scripting.FileSystemObject"); 
    f = fso.OpenTextFile(jsFile); 
    s = f.ReadAll(); 
    f.Close(); 
    return(s); 
}

that requires the user to invoke eval(Include("File.js")) which is not desirable for me. I prefer a solution where I can have a clean include() function. Here are what I have found so far:

• If JScript had a function similar to VBScript's ExecuteGlobal, then the problem would be easily solved. Sadly JScript only has the eval() function that executes the input string in the local scope. I tried return eval(<commands>) in the above function to no avail.
• If it was possible to include XSLT in WSH's .wsf/.wsc files, then one could potentially define the include() function on XML level something like (sorry, I don't know XML/XSLT, and this is just pseudocode)

<xsl:function name="JS:include">
    <xsl:param name="fileName"/>
    <script language="JScript" src="fileName"/>
</xsl:function>

• if the WSH's XML elements had a .appendChild() method, like HTA's HTML .hta files do, then we could do something like (reference):

function include(inputFile){
    var head = document.head;
    var script = document.createElement('script');
    script.language = 'JScript';
    script.src = inputFile
    head.appendChild(script);
}

None of the options above seem to be available. I would appreciate it if you could help me know if/how I can implement a clean include() function in the classic JScript. Thanks for your support in advance.

Answer 1

If I'm understanding what you're trying to do is to call an XSL extension function, that is written in JavaScript. Here's an example .wsf that takes as an input an xml file, and an xsl file, and outputs the transformed result.

It illustrates how to call a javascript extension function. For this example the javascript extension function is a "objDate" object that converts an Epoch date, into a formatted string.

Hope this helps, otherwise I've wasted my evening trying to help you out!

Sorry this is long, but there's no other way :)

Here's what's included...

complete .WSF file (save to t.wsf) sample XML (save to t.xml) sample XSL (save to t.xsl) the output.

To run the example, make sure you have MSXML installed then run

cscript t.wsf t.xml t.xsl

Sample t.wsf file

<package>
<job id="t1">
<script language="JScript">

try {
    var objArgs = WScript.Arguments;
    if( objArgs.length < 2) {
        WScript.Echo( "Usage: xform.wsf file.xml, file.xsl" );
        WScript.Quit( 1 ); // no FTP
    }

    var xml = loadXML( objArgs(0) );
    var xsl = loadXML( objArgs(1) );
    var aParms = new Array();
    aParms["testparm"] = "XSL Rocks!";
    var xmlResult = transform( xml, xsl, aParms );

    // just dump out the result
    WScript.Echo( xmlResult.xml );
} catch ( err ) {
    WScript.Echo( err.description );
}

// Creates a DOM document, with the proper parameters set, version 1.1
function newXML() {
    var strDOMObject = "MSXML2.FreeThreadedDOMDocument";
    var xml = new ActiveXObject( strDOMObject );
    xml.setProperty( "SelectionLanguage", "XPath" ); // i.e. not XSLT
    xml.resolveExternals = 0;
    xml.validateOnParse = 0;
    xml.preserveWhiteSpace = true;

    try {
        // configure the document to allow for Microsoft extensions within XPath
        xml.setProperty("SelectionNamespaces", " xmlns:ms='urn:schemas-microsoft-com:xslt' xsl='http://www.w3.org/1999/XSL/Transform' :html='http://www.w3.org/1999/xhtml' " ); 
        xml.setProperty("NewParser", true ); // 2 - 4x performance improvement, NO async, NO DTD validation
    } catch (e) {
        delete e;
    }   
    return xml;
}

// loads XML from disk, with exceptions
function loadXML( strFileName ) {
    var xml = this.newXML();
    var strErrMsg = '';
    try {
        if( !xml.load( strFileName ) ) {
            processLoadError( xml );
        }
    } catch( e ) {
        strErrMsg = "Error loading " + strFileName + ":" + e.description;
        e.description = strErrMsg;
        throw e;
    }
    return xml;
}

function processLoadError( xml ) {
    var strErrMsg = '';
    strErrMsg = xml.parseError.reason;
    if( xml.parseError.srcText != "" )
        strErrMsg += "Source: " + xml.parseError.srcText + "\r\n";
    if( xml.parseError.line != 0 )
        strErrMsg += "Line: " + xml.parseError.line + "\r\n";
    if( xml.parseError.linepos != 0 )
        strErrMsg += "Position: " + xml.parseError.linepos + "\r\n";
    throw new Error( xml.parseError.errorCode, strErrMsg ); 
}

function transform( xml, xsl, aParms ) {
    try {
        var strDOMObject = "MSXML2.FreeThreadedDOMDocument";
        var strTemplateObject = "MSXML2.XSLTemplate";
        var xslt = new ActiveXObject(strTemplateObject );
        var xmlReturn = new ActiveXObject( strDOMObject );
        var xslProc;
        xslt.stylesheet = xsl;
        xslProc = xslt.createProcessor();
        xslProc.input = xml;


        // create and add in the extension object
        var dt = new objDate();
        xslProc.addObject( dt, "urn:dt");   

        if( aParms ) {
            for( key in aParms ) {
                if( (typeof(aParms[key]) != "undefined") && ( aParms[key] != null ) ) {
                    xslProc.addParameter( key, aParms[key] );
                }
            }
        }
        xslProc.transform();
        if( !xmlReturn.loadXML( xslProc.output ) ) {
            processLoadError( xmlReturn );
        }
        return xmlReturn;
    } catch( e ) {
        e.description = "Error transforming XML: " + e.description;
        throw e;
    }
}


// Simple Date Object, add in your own methods here...
function objDate() {
    // Methods, to be called from XSLT
    this.DateParse = objDate_DateParse;
}

function objDate_DateParse( objNodeList) {
    if( !objNodeList.length ) 
        return ""; // no date from the XSL, return an empty string

    // XSL passes in a collection, typically only 1, but for this exmaple, just get the last one
    for( i = 0; i < objNodeList.length; i++ ) {
        var strDate = objNodeList(i).text;
    }

    var dt = new Date( parseInt( strDate ) );
    var strReturn = (dt.getMonth() + 1 ) + "/" + dt.getDate() + " " + dt.getHours() + ":" + dt.getMinutes();
    return  strReturn;
}
</script> 
</job>
</package>

Next a sample XML, with an Epoch @dt in each row.

<xml>
    <row id='123' dt='1605666152744'/>
    <row id='234' dt='1605766152744'/>
    <row id='345' dt='1605866152744'/>
</xml>

Then the XSL that calls the javascript extension object "dt". Note that you have to declare the namespace at the top of the XSL.

<?xml version='1.0'?>
<xsl:stylesheet version="1.0" xmlns:dt="urn:dt" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:msxsl="urn:schemas-microsoft-com:xslt">
<xsl:output method="xml" indent="yes" omit-xml-declaration="yes"/>

<xsl:param name='testparam'/>
<xsl:variable name='list' select='//row'/>

<xsl:template match='/'>
<div>
    <h1>Test XSL with Date Extension - <xsl:value-of select='$testparam'/></h1>
    <table class='table'>
        <thead>
            <tr>
                <th>Name</th>
                <th>Date</th>
            </tr>
        </thead>
        <tbody>
            <xsl:for-each select='$list'>
                <tr>
                    <td><xsl:value-of select='@id'/></td>
                    <td><xsl:value-of select='dt:DateParse(  @dt )'/></td>
                </tr>
            </xsl:for-each>
        </tbody>
    </table>
</div>
</xsl:template>
</xsl:stylesheet>

Finally the result, note the formatted dates, from the Epoch Dates.

<div xmlns:dt="urn:dt" xmlns:msxsl="urn:schemas-microsoft-com:xslt">
        <h1>Test XSL with Date Extension - </h1>
        <table class="table">
                <thead>
                        <tr>
                                <th>Name</th>
                                <th>Date</th>
                        </tr>
                </thead>
                <tbody>
                        <tr>
                                <td>123</td>
                                <td>11/17 21:22</td>
                        </tr>
                        <tr>
                                <td>234</td>
                                <td>11/19 1:9</td>
                        </tr>
                        <tr>
                                <td>345</td>
                                <td>11/20 4:55</td>
                        </tr>
                </tbody>
        </table>
</div>