wsc-mvc/Framework/ViewRenderer.wsc

<?xml version="1.0"?>
<?component error="true" debug="false"?>
<component>
<registration
    description="WscMvc ViewRenderer"
    progid="WscMvc.ViewRenderer"
    version="1.00"
    classid="{4948DF84-5DC6-448A-9F1B-EB596C28842B}">
</registration>

<public>
    <method name="Render">
        <parameter name="viewsDir"/>
        <parameter name="viewName"/>
        <parameter name="data"/>
        <parameter name="output"/>
    </method>
</public>

<script language="VBScript">
<![CDATA[
Option Explicit

' Loads a separate .html template and substitutes {{Key}} placeholders with
' HTML-encoded values from a Scripting.Dictionary. Never references ASP
' intrinsics - viewsDir is a plain path string resolved by the caller (same
' pattern as RequestContext's logDir). Only text-context HTML encoding is
' implemented (SPEC SS8); attribute/URL/JS-context encoding is out of scope
' until a view actually needs it. Template content is never executed as
' VBScript or evaluated as an expression - substitution is a single literal
' scan-and-replace pass.
Sub Render(viewsDir, viewName, data, output)
    Dim fso, templatePath, template, stream

    output = ""

    If Not IsValidViewName(viewName) Then
        Err.Raise vbObjectError + 1, "WscMvc.ViewRenderer", "Invalid view name"
    End If

    Set fso = CreateObject("Scripting.FileSystemObject")
    templatePath = viewsDir & "\" & viewName & ".html"

    If Not fso.FileExists(templatePath) Then
        Set fso = Nothing
        Err.Raise vbObjectError + 2, "WscMvc.ViewRenderer", "View template not found"
    End If

    Set stream = fso.OpenTextFile(templatePath, 1) ' 1 = ForReading
    template = stream.ReadAll
    stream.Close
    Set stream = Nothing
    Set fso = Nothing

    output = ExpandTemplate(template, data)
End Sub

Function IsValidViewName(viewName)
    Dim i, c
    IsValidViewName = False
    If IsNull(viewName) Or IsEmpty(viewName) Then Exit Function
    If Len(viewName) = 0 Then Exit Function
    For i = 1 To Len(viewName)
        c = Mid(viewName, i, 1)
        If Not ((c >= "A" And c <= "Z") Or (c >= "a" And c <= "z") Or _
                (c >= "0" And c <= "9") Or c = "_" Or c = "-") Then
            Exit Function
        End If
    Next
    IsValidViewName = True
End Function

' Single left-to-right scan for {{Key}} tokens. Unterminated "{{" and a key
' with no matching dictionary entry are both treated as template-authoring
' errors (Err.Raise) rather than emitted as literal text, so rendered output
' is always fully resolved - never partially-substituted markup.
Function ExpandTemplate(template, data)
    Dim result, pos, openPos, closePos, key, hasKey

    result = ""
    pos = 1

    Do
        openPos = InStr(pos, template, "{{")
        If openPos = 0 Then
            result = result & Mid(template, pos)
            Exit Do
        End If

        result = result & Mid(template, pos, openPos - pos)

        closePos = InStr(openPos + 2, template, "}}")
        If closePos = 0 Then
            Err.Raise vbObjectError + 3, "WscMvc.ViewRenderer", "Unterminated view placeholder"
        End If

        key = Trim(Mid(template, openPos + 2, closePos - openPos - 2))

        hasKey = False
        If Not data Is Nothing Then
            If data.Exists(key) Then hasKey = True
        End If
        If Not hasKey Then
            Err.Raise vbObjectError + 4, "WscMvc.ViewRenderer", "Unresolved view placeholder"
        End If

        result = result & HtmlEncode(CStr(data(key)))
        pos = closePos + 2
    Loop

    ExpandTemplate = result
End Function

Function HtmlEncode(s)
    Dim r
    r = s
    r = Replace(r, "&", "&amp;")
    r = Replace(r, "<", "&lt;")
    r = Replace(r, ">", "&gt;")
    r = Replace(r, """", "&quot;")
    r = Replace(r, "'", "&#39;")
    HtmlEncode = r
End Function
]]>
</script>
</component>