# File: laszlo.rnc
#
# lzx.rnc is in the RELAXNG Compact syntax:
# http://www.thaiopensource.com/relaxng/compact/syntax.html
#
# lzx.rng is a RELAXNG schema:
# http://www.oasis-open.org/committees/relax-ng/
#
# Note: This is the master schema. lzx.dtd, lzx.rng, lzx.xsd, and lzxdoc.rng
# are all generated from this file.

# * P_LZ_COPYRIGHT_BEGIN ******************************************************
# * Copyright 2001-2007 Laszlo Systems, Inc.  All Rights Reserved.            *
# * Use is subject to license terms.                                          *
# * P_LZ_COPYRIGHT_END ********************************************************

default namespace = "http://www.laszlosystems.com/2003/05/lzx"
namespace rng = "http://relaxng.org/ns/structure/1.0"
namespace a = "http://relaxng.org/ns/compatibility/annotations/1.0"
datatypes xsd = "http://www.w3.org/2001/XMLSchema-datatypes"
namespace lza = "http://www.laszlosystems.com/annotations/1.0"

# Literals
booleanLiteral = xsd:boolean
colorLiteral = string
numberLiteral = xsd:double
sizeLiteral = xsd:double {minInclusive="0"}
inheritableBooleanLiteral = booleanLiteral | "inherit"
constraint = xsd:string {pattern="$(style|path|immediately|once|always)?\{.*\}"}

# Attribute value types
boolean = booleanLiteral | constraint
booleanOrNull = boolean | "null"
color = colorLiteral | constraint
script = string
expression = string
reference = string
number = numberLiteral | constraint
size = sizeLiteral | constraint
numberExpression = string
sizeExpression = string
css = string
opacity = xsd:double {minInclusive="0.0" maxInclusive="1.0"} | constraint
percentage = xsd:string {pattern="(\d+(.\d?)|.\d+)%"}

# Grammar
start = canvas | viewElement | library

canvas =
element canvas {
  idAttribute? &
  oninitAttribute?
  & ## The width of the canvas.
    [a:defaultValue="500"]
    attribute width {sizeLiteral | percentage}?
  & ## The height of the canvas.
    [a:defaultValue="400"]
    attribute height {sizeLiteral | percentage}?
  & ## The background color of the canvas.
    [a:defaultValue="white"] attribute bgcolor {colorLiteral}?
  & ## The string that is used in the browser window.
    [a:defaultValue="OpenLaszlo Application"] attribute title {string}?
  & ## The default font for views in this application.
    [a:defaultValue="lztahoe8"] attribute font {string}?
  & ## The default size for views in this application.
    [a:defaultValue="8"] attribute fontsize {size}?
  & ## The default font style for views in this application.  The empty string
    ## is interpreted as 'plain'.
    [a:defaultValue=""] attribute fontstyle
      {"bold" | "italic" | "bold italic" | "plain" | ""}?
  & attribute layout {css}?
  & ## If false, disables validation against the schema during compilation
    [a:defaultValue="true"] attribute validate {booleanLiteral}?
  & [a:defaultValue="inherit"] attribute proxied {inheritableBooleanLiteral}? 
  & [a:defaultValue="false"] attribute debug {booleanLiteral}?
  & [a:defaultValue="false"] attribute backtrace {booleanLiteral}?
  & ## If present, specifies the maximum width in pixels of any output text field.
    ## Text which extends beyond this width will be clipped.
    ## If this attribute is omitted, it defaults to the canvas width.
    attribute maxtextwidth {sizeLiteral}?
  & ## If present, specifies the maximum height in pixels of any output text field.
    ## Text which extends beyond this height will be clipped.
    ## If this attribute is omitted, it defaults to the canvas height.
    attribute maxtextheight {sizeLiteral}?
  & attribute dataloadtimeout {numberExpression}?
  & attribute medialoadtimeout {numberExpression}?
  & ## A list of names for libraries that are included in the application.
    [a:defaultValue=""] attribute libraries {string}?
  & [a:defaultValue="true"] attribute embedfonts {booleanLiteral}?
  & connection?
  & splash?
  & datapathChildren
  & toplevelElements
  & [a:defaultValue="1.1"] attribute version {string}?
  & [a:defaultValue="false"] attribute accessible {booleanLiteral}?
}

library =
element library {
  [lza:visibility="private"]
  attribute href {xsd:anyURI} |
  ([lza:visibility="private"] attribute includes {string}? &
   [a:defaultValue="inherit"] attribute proxied {booleanLiteral | "inherit"}? &
   (toplevelElements &
    [a:defaultValue="true"] attribute validate {booleanLiteral}? 
    & datapointer*))
}

toplevelElements = (
    (viewElement | scriptElement | styleSheetElement | asset | font)*
  & datarequest*
  & datasource*
  & connectiondatasource*
  & dataset*
  & debugger?
  & command*
  & objectElements
  & class*
  & interface*
  & trait*
  & includeElement*
  & importElement*
  & library*
  & layout*
  & security*
  & toplevelSwitch*
)

debugger = 
[lza:since="1.1"]
element debug {
   viewAttributes &
   attribute showInternalProperties {boolean}?
}

includeElement =
element include {
     attribute href {xsd:anyURI}
  & [a:defaultValue="xml"]
    attribute type {"text" | "xml"}?
}

toplevelSwitch = element switch {
  element when {
    attribute runtime {xsd:string}? &
    toplevelElements
  }* &
  element otherwise {
    toplevelElements
  }?
}

#
# Attributes
#

idAttribute =
  [lza:modifiers="final"]
  attribute id {xsd:ID}
srcAttribute =
  ## The path of a file that contains the source for this object.
  [lza:modifiers="final"]
  attribute src {xsd:anyURI}
nameAttribute =
  ## The name of a variable that will be set to this object when the
  ## application is started.  If this element is directly within a @e{canvas}
  ## or @e{library} element, the global variable and the canvas
  ## property with this name will be set to this object.  If this
  ## element is within another object, that object's property with
  ## this name will be set to this object.
  [lza:modifiers="final"]
  attribute name {token}
oninitAttribute =
  ## The oninit script is executed once, after the element's
  ## children, if any, have been initialized.
  attribute oninit {script}
initstageAttribute =
  [a:defaultValue="normal"
   lza:modifiers="final"]
    attribute initstage {"early" | "normal" | "late" | "immediate" | "defer"}
datapathAttribute =
  attribute datapath {string}
placementAttribute =
  [lza:modifiers="final"]
  attribute placement {string}
classAttribute =
  ## The CSS class of a node
  [lza:modifiers="final"]
  attribute class {token}
ignoreplacementAttribute =
  [lza:modifiers="final"]
  attribute ignoreplacement {boolean}

objectAttributes = (
  idAttribute?,
  nameAttribute?,
  classAttribute?,
  oninitAttribute?,
  datapathAttribute?,
  placementAttribute?,
  ignoreplacementAttribute?,
  initstageAttribute?
)

viewAttributes = (
  nodeAttributes,
    [a:defaultValue="1.0"]
    attribute opacity {opacity}?,
  attribute bgcolor {color}?,
  attribute cursor {token}?,
  attribute clickable {boolean}?,
  attribute clickregion {string}?,
  attribute focustrap {boolean}?,
  attribute focusable {boolean}?,
  [a:defaultValue="0"]
  attribute frame {numberExpression}?,
  attribute fgcolor {color}?,
  attribute font {string}?,
  attribute fontstyle {string}?,
  attribute fontsize {size}?,
  attribute resource {string}?,
  [lza:visibility="private"]
  attribute source {expression}?, 
  [a:defaultValue="false"
   lza:modifiers="final"]
  attribute clip {boolean}?,
  [a:defaultValue="left"
   lza:modifiers="final"]
   attribute align {"left" | "center" | "right" | constraint}?, 
  [a:defaultValue="top"] attribute valign {"top" | "middle" | "bottom" | constraint}?, 
  attribute layout {css}?,
  [a:defaultValue="false"
   lza:modifiers="final"]
  attribute pixellock {booleanLiteral}?,
  [a:defaultValue="0"] attribute rotation {numberExpression}?,
  [a:defaultValue="0"] attribute xoffset {numberExpression}?,
  [a:defaultValue="0"] attribute yoffset {numberExpression}?,
  [a:defaultValue="true"]
  attribute play {boolean}?,
  #[a:defaultValue="true"]
  attribute selectiontype
       {"none" | "single" | "toggle" | "multi" | "range"}?,
  attribute stretches {"width" | "height" | "both"}?,
  [a:defaultValue="true"] attribute visible {booleanOrNull}?,
  [a:defaultValue="visible"] attribute visibility {string}?,
  attribute width {sizeExpression}?,
  attribute height {sizeExpression}?,
  [lza:visibility="private"]
  attribute textwidth {sizeExpression}?,
  [lza:visibility="private"]
  attribute textheight {sizeExpression}?,
  [a:defaultValue="0"]
    attribute x {numberExpression}?,
  [a:defaultValue="0"]
    attribute y {numberExpression}?,
  attribute aaname {string}?,
  attribute aaactive {boolean}?,
  attribute aadescription {string}?,
  attribute aatabindex {number}?,
  attribute aasilent {boolean}?,
  attribute showhandcursor {boolean}?,
  [lza:modifiers="final"]
  attribute options {css}?,
  eventAttributes
)

eventAttributes =
  attribute onclick {script}?,
  attribute ondblclick {script}?,
  attribute onmousedown {script}?,
  attribute onmouseup {script}?,
  attribute onmouseover {script}?,
  attribute onmouseout {script}?,
  attribute onfocus {script}?,
  attribute onblur {script}?,
  attribute onkeydown {script}?,
  attribute onkeyup {script}?,
  attribute onselect {script}?,
  attribute ondata {script}?



#
# View Content
#

viewContent = viewAttributes & viewContentElements
viewContentElements = nodeElements

viewContentElements &=
  includeElement*
  & viewElement*
  & element dataselectionmanager {
      idAttribute? &
      nameAttribute?
      & attribute toggle {boolean}?
      & oninitAttribute?
      & objectElements
  }?
  & element selectionmanager {
      idAttribute?
      & nameAttribute?
      & attribute toggle {boolean}?
      & oninitAttribute?
      & objectElements
  }*
  & layout*

viewContentElements &= command*
command =
  element command {
    idAttribute?,
    nameAttribute?,
    attribute onselect {script}?,
    attribute active {boolean}?,
    attribute key {expression}?,
    oninitAttribute?,
    objectElements
  }

animator =

  element animator {animatorContent}

animatorgroup =

  element animatorgroup {
    [a:defaultValue="sequential"]
    attribute process {"sequential" | "simultaneous"}? &
    animatorContent}

animatorContent =
  objectAttributes &
  objectElements &
  attribute attribute {token}? &
  [a:defaultValue="true"] attribute start {boolean}? &
  attribute from {number}? &
  attribute to {number}? &
  attribute duration {xsd:float {minInclusive="0"} | constraint}? &
  [a:since="1.1"
   a:defaultValue="false"]
  attribute indirect {boolean}? &
  [a:defaultValue="false"] attribute relative {boolean}? &
  [a:defaultValue="easeboth"]
  attribute motion {"linear" | "easein" | "easeout" | "easeboth"}? &
  attribute onstart {script}? &
  attribute onstop {script}? &
  [lza:since="1.1"]
  attribute repeat {expression}? &
  [a:defaultValue="false"] attribute paused {boolean}? &
  attribute target {reference}?


#
# View elements
#

viewElement = (

  element view {viewContent}
  | 
    element text {
      viewContent
      & textAttributes
      & attribute embedfonts {boolean}?
      & (attribute text {xsd:string}
        | htmlText*)
    }
   | 
    element inputtext {
      viewContent &
      textAttributes &
      attribute embedfonts {boolean}? &
      attribute resizable {boolean}? &
      ## If true, the input text field acts like a password input
      ## field; any text typed in appears as "****" characters in the
      ## current font.
      [a:defaultValue="false"]
        attribute password {boolean}?
      & (attribute text {xsd:string}
        | text?)
    }
)

textAttributes =
  [a:defaultValue="false"
   lza:modifiers="final"]
  attribute multiline {boolean}? &
  [a:defaultValue="false"]
  attribute resize {booleanLiteral}? &
  [a:defaultValue="false"]
  attribute selectable {booleanLiteral}? &
  [a:defaultValue="null"]
  attribute maxlength {numberExpression}? &
  attribute pattern {string}? &
  attribute label {string}? &
     [a:defaultValue="advanced"]
  attribute antiAliasType {"normal" | "advanced"}? &
     [a:defaultValue="subpixel"]  
  attribute gridFit {"none" | "pixel" | "subpixel"}? &
     [a:defaultValue="0"]
  attribute sharpness {numberExpression}? &
     [a:defaultValue="0"]  
  attribute thickness {numberExpression}?
    
textContent =
  (attribute text {xsd:string}
   | text?)

htmlContent =
  (attribute text {xsd:string}
   | htmlText?)

htmlText = (text
 | 
   element pre { htmlText }
 | 
   element a {
     ## The link target.
     attribute href {xsd:anyURI} &
      ## The value of this attribute determines where the link target
      ## will be displayed.  The interpretation is the same as in HTML,
      ## where the "current frame" is the frame containing the LZX
      ## application.  The value must be a name beginning with an
      ## alphabetic character, or one of the following:
      ##
      ## <dl>
      ##     <dt> @c{_blank} </dt>
      ##     <dd>
      ##         The user agent should load the designated
      ## document in a new, unnamed window.
      ##     </dd>
      ##     <dt> @c{_parent} </dt>
      ##     <dd>
      ##         The user agent should load the document into
      ## the full, original window (thus canceling all other
      ## frames). This value is equivalent to @c{_self} if the current
      ## frame has no parent.
      ##     </dd>
      ##     <dt> @c{_self} </dt>
      ##     <dd>
      ##         The user agent should load the document in
      ## the same frame as the element that refers to this target.
      ##     </dd>
      ##     <dt> @c{_top} </dt>
      ##     <dd>
      ##         The user agent should load the document into
      ## the immediate FRAMESET parent of the current frame. This
      ## value is equivalent to @c{_self} if the current frame has no
      ## parent.
      ##     </dd>
      ## </dl>
     attribute target {"_blank" | "_parent" | "_self" | "_top" |
                       xsd:string {pattern="[a-zA-Z][a-zA-Z0-9\-_:.]*"}}? &
     htmlText
   }
 | 
   element b {htmlText}
 | 
   element li {htmlText}
 | element img {
       attribute src {string}?
       & attribute align {string}?
       & attribute width {string}?
       & attribute height {string}?
       & attribute hspace {string}?
       & attribute vspace {string}?
   }
 | 
  [lza:name="HTML font"]
   element font {
       # The name of the font face.  This must match the @a{name} of
       # a font declared by a top-level <tagname>font</tagname> tag.
       # It has the same meaning as the <attribute>view.font</attribute>
       # attribute.  This value may not be a constraint.
       attribute face {string}?
       # The size of the font.  This has the same meaning as the
       # <attribute>view.fontsize</attribute>.  This value may not
       # be a constraint.
     & attribute size {sizeLiteral}?
       # The color of the font.  This has the same meaning as the
       # <attribute>text.fgcolor</attribute> attribute.  Unlike that
       # attribute, the value of <attribute>size</attribute> must be
       # a compile-time constant of the form <code>#FF0000</code>.
       # The CSS syntaxes <code>red</code>, <code>#F00</code>, and
       # <code>rgb(1.0, 0, 0)</code> are not recognized.
     & attribute color {colorLiteral}?
     & htmlText} 
 |
   element i {htmlText}
 | 
   element p {htmlText}
 | 
   element br {empty}
 |
   element u {htmlText})*

#
# Assets
#

asset =

element audio {srcAttribute & idAttribute? & nameAttribute} 

asset |= resource

resource =
  
  element resource {
    nameAttribute &
    (srcAttribute
    | 
      element frame {nameAttribute? & srcAttribute}*)
  }


#
# Data
#
datasource = element datasource {
    idAttribute?
  & nameAttribute?
  & attribute timeout {number}?
  & [a:defaultValue="false"
     lza:visibility="private"]
    attribute secure {booleanLiteral}?
  & [a:defaultValue="inherit"] attribute proxied {booleanLiteral | "inherit"}? 
  & ## A dataset element within a @e{datasource} element defines a set
    ## of data that is retrieved from that datasource.  The name
    ## of the dataset can be used in the datapath attribute of
    ## a view.
    [lza:name="datasource dataset"]
    element dataset {datasetAttributes & anyXML}*
  & oninitAttribute?
  & objectElements
}

connectiondatasource = 
## A connection datasource to receive messages from the persistent connection.
element connectiondatasource {
    idAttribute?
  & nameAttribute?
  & ## The onconnect script is executed when the application is connected.
    attribute onconnect {script}?
  & attribute oninit {script}?
  & ## The ondata script is executed when the application receives a persistent
    ## connection message.
    attribute ondata {script}?
  & ## The onerror script is executed whenever there's a connection failure.
    attribute onerror {script}?
  & ## The ontimeout script is executed whenever a timeout is encountered with
    ## the persistent connection.
    attribute ontimeout {script}?
  & ## The ondisconnect script is executed whenever the application disconnects.
    attribute ondisconnect {script}?
  & ## The onuserdisconnect script is executed whenever a user disconnects. See
    ## the receiveuserdisconnect attribute.
    attribute onuserdisconnect {script}?
  & ## A dataset element within a @e{connectiondatasource} element names a
    ## unique dataset whose content is shared with other clients that define a
    ## dataset with the same name on the same server.
    [lza:name="persistent connection dataset"]
    element dataset {datasetAttributes}*
  & method*
}

agent = 
element agent {
    attribute url {string}
}

connection =

element connection {
    ## The interval value in milliseconds that the server will send a message to
    ## the application to ensure the connection is kept alive by the client.
    ## The default value of a heartbeat is 5000 milliseconds.
    attribute heartbeat {xsd:integer}?
  & attribute timeout {number}?
  & ## If true, creates a secure persistent connection through https. Otherwise
    ## the connection uses http.
    attribute secure {booleanLiteral}?
  & ## Connection port.
    attribute secureport {xsd:integer}?
  & ## Tells server to send an onuserdisconnect event every time a user 
    ## disconnects. Default is false.
    [a:defaultValue="false"]
    attribute receiveuserdisconnect {booleanLiteral}?
  & ## Connection group name.
    attribute group {string}?
  & ## Class name of server-side java authenticator
    attribute authenticator {string}?
  & ## Authenticator parameters.
    attribute authparam {string}?
  & ## The onconnect script is executed when the application is connected.
    attribute onconnect {script}?
  & ## The ondata script is executed when the application receives a persistent
    ## connection message.
    attribute ondata {script}?
  & ## The onerror script is executed whenever there's a connection failure.
    attribute onerror {script}?
  & ## The ontimeout script is executed whenever a timeout is encountered with
    ## the persistent connection.
    attribute ontimeout {script}?
  & ## The ondisconnect script is executed whenever the application disconnects.
    attribute ondisconnect {script}?
  & ## The onuserdisconnect script is executed whenever a user disconnects. See
    ## the receiveuserdisconnect attribute.
    attribute onuserdisconnect {script}?
  & agent*
  & method*
  & handler*
}

dataset =

[lza:name="top-level dataset"]
element dataset {
  datasetAttributes & anyXML
}

datasetAttributes = objectAttributes & 
  ## If true, namespace prefixes are preserved in XML tag and attribute names
  ## defaults to false in proxied apps, but SOLO apps currently only support
  ## a value of 'true' (namespace prefixes are always attached to
  ## element and attribute names)
  [lza:defaultValue="true"]
  attribute nsprefix {boolean}? &
  ## If true, enable a response to be encoded via the clients Accept-Encoding
  ## HTTP header.  This allows the server to gzip the response.
  [lza:since="1.1"
   lza:defaultValue="false"]
  attribute acceptencodings {boolean}? &
  ## msecs to time out for load requests
  attribute timeout {number}? & 
  ## If false, use flash native XML loader/parser
  [a:defaultValue="inherit"] attribute proxied {booleanLiteral | "inherit"}? &
  ## If this is a URL, it defines a request for an XML datasource that
  ## is initiated when the dataset's content is requested.
  ## If this is a pathname, it specifies an XML file whose content
  ## is compiled into the application as the value of the dataset.
  attribute src {xsd:anyURI | constraint}? &
  ## Request this dataset when the app starts.
  [lza:since="1.1"
   lza:defaultValue="false"]
  attribute request {boolean}? &
  ## If true, every change to the dataset source or query params will
  ## cause a new request to be made automatically
  [lza:since="4.1"
   lza:defaultValue="false"]
  attribute autorequest {boolean}? &
  ## If true, the client should ensure that each request is made,
  ## rather than just making and reporting the last request.
  [lza:since="1.1"
   lza:defaultValue="false"]
  attribute queuerequests {boolean}? &
  ## This string is appended to the request.
  [lza:since="1.1"]
  attribute querystring {xsd:string}? &
  ## If set to "http", then the dataset will interpret its src attribute as an
  ## url from which to load its content, rather than as a static xml file to
  ## inline.
  attribute type {xsd:string}? &
  ## If true, initial literal XML data is taken from <data> child node
  attribute datafromchild {boolean}? &
  [lza:visibility="private"]
  attribute endpoint {xsd:string}? &
  [lza:visibility="private"]
  attribute namespace {xsd:string}? &
  [lza:visibility="private"]
  attribute method {xsd:string}?
    & ## specifies whether or not the app-LPS connection is secure
    [a:defaultValue="false"]
    attribute secure {booleanLiteral}?
  & ## Sets the port number to use to connect to the LPS for a secure
    ## connection. 
    [a:defaultValue="443"
     lza:since="1.1"]
    attribute secureport {xsd:integer {minInclusive="0"}}?
  & 
  ## If true, include response headers (This is specific to HTTP datasets).
  [a:defaultValue="true"]
  attribute getresponseheaders {boolean}?
  & 
  ## If true, trim whitespace around XML text content
  [a:defaultValue="false"]
  attribute trimwhitespace {boolean}?
  & 
  ## Enables caching of the data response on both the LPS server
  ## and the client.  There are security issues with enabling this.
  ## You usually want the getresponseheaders attribute to be false when
  ## you set this to true.
  [a:defaultValue="false"]
  attribute cacheable {boolean}? &
  ## The ondata script is executed when data arrives
  [lza:since="1.1"]
  attribute ondata {script}? &
  ## The onerror script is executed when an error occurs
  [lza:since="1.1"]
  attribute onerror {script}? &
  ## The ontimeout script is executed when a request times out
  [lza:since="1.1"]
  attribute ontimeout {script}? &
  ## HTTP request method = post | get
  attribute querytype {"get" | "post" | "GET" | "POST" | "put" | "PUT" | "delete" | "DELETE"}?

anyXML = mixed {
    element * {
      attribute * {string}* &
      anyXML
    }*
  }

dataptrAttributes =
  attribute ondata {script}? &
  attribute onerror {script}? &
  attribute ontimeout {script}? &
  attribute rerunxpath {boolean}? &
  attribute xpath {string}? &
  ## This controls the spacing between elements if <a
  ## href="datapath.html#attr-replication">lazy replication</a> is
  ## true.
  [a:defaultValue="0"]
  attribute spacing {size}?

datapointer =
  element datapointer {
    objectAttributes &
    dataptrAttributes &
    attribute p {expression}? &
    objectElements
  }

datapath =
  element datapath {
    objectAttributes &
    dataptrAttributes &
    ## If pooling is true, views that are data-bound to this datapath
    ## are recycled if the dataset changes.  Otherwise, views are deleted
    ## when the data nodes they are bound to disappear, and created
    ## when new data nodes match the datapath.
    [a:since="1.1"
     a:defaultValue="false"]
    attribute pooling {boolean}? &
    attribute axis {"x" | "y" }? &
    attribute sortpath {string}? &
    attribute sortorder {string}? &
    attribute replication {"normal" | "lazy" | "resize" }? &
    [lza:visibility="private"]
    attribute p {expression}? &
    objectElements
  }

datapathChildren = 
    datapath?
  & datapointer*

#
# Fonts
#
deviceAttribute = attribute device {boolean}?


font =
  
  element font {
    nameAttribute &
    deviceAttribute? &
    ((srcAttribute & styleAttribute? & faceElement*)
     | faceElement+)?
  }

faceElement =
  ## Defines a font face or style within the font family that the
  ## outer element defines.
  element face {styleAttribute? & srcAttribute}

styleAttribute =
  ## Corresponds to the fontstyle attribute of a view.
  attribute style {"bold" | "italic" | "bold italic" | "italic bold" | "plain" } # TBD: actually, a list of "bold" or "italic"


#
# Class system
#

objectElements = method*
  & handler*
  & event*
  & attributeElement*
  & state*
  & node*
  & animator*
  & animatorgroup*

attributeElement = 
element attribute { 
        [lza:modifiers="final"]
        attribute name {token} 
     & (attribute value {string} ?
           & [lza:since="1.1"]
             ([a:defaultValue="immediately"]
               attribute when { "immediately" | "once" | "always" }
             )?
       )?
     & [a:defaultValue="expression"
        lza:modifiers="final"]
       attribute type {"boolean" | "color" | "expression" | "number" | "size" |
                       "string" | "text" | "html"}?
     & [a:defaultValue="false"] 
       attribute required {booleanLiteral}? 
     & [lza:since="1.1"]
       attribute setter {script}?
     }

class = 
  element class  {
     ## The name of a new tag that this element defines.
     [lza:modifiers="final"]
     attribute name {token} &
     ## The name of the tag that this tag extends.
     [a:defaultValue="view"
      lza:modifiers="final"]
     attribute extends {token}? &
     ## The comma-separated list of mixins, applied in order
     attribute with {string}? &
     ## Any attribute can occur, depending on superclass.
     ## We need to handle this in a preprocessing step.
     attribute * - (name|extends|with) {string}*
   & docElement?
   & viewContentElements
  }

interface =
  element interface  {
     ## The name of a new tag that this element defines.
     [lza:modifiers="final"]
     attribute name {token} &
     ## The name of the tag that this tag extends.
     [a:defaultValue="view"
      lza:modifiers="final"]
     attribute extends {token}? &
     ## Any attribute can occur, depending on superclass.
     ## We need to handle this in a preprocessing step.
     attribute * - (name|extends|traits) {string}*
   & docElement?
   & viewContentElements
  }

docElement =
    element doc {
        # it actually has more structure than this,
        # but the DTD compiler chokes if we get too descriptive here.
        any
    }

any = (text | element * { attribute * { text }*, any })*

trait =
  element trait {
     ## The name of a new tag that this element defines.
     [lza:modifiers="final"]
     attribute name {token} &
     ## Any attribute can occur
     ## We need to handle this in a preprocessing step.
     attribute * - (name) {string}*
   & viewContentElements
  }

handler =
  element handler {
     nameAttribute
   & [a:defaultValue="this"]
     attribute reference {reference}?
   & (([a:defaultValue=""
        lza:modifiers="final"]
       attribute args {string}? &
       text) |
      (attribute method {string}))
  }

event =
  element event {
    nameAttribute
  }

method =
  element method {
   (nameAttribute |
    (nameAttribute? &
     attribute event {string} &
     [a:defaultValue="this"]
     attribute reference {reference}?)) &
   [a:defaultValue=""
   lza:modifiers="final"]
   attribute args {string}? &
   text
  }

importElement =
  element import {
    viewContent &
    ## A reference to a target file whose content is treated as a loadable module
    attribute href {xsd:anyURI} 
   & attribute stage {"late" | "defer" }
   & attribute onload {script}?
   & [a:defaultValue="inherit"] attribute proxied {booleanLiteral | "inherit"}? 
   & attribute onerror {script}?
   & attribute ontimeout {script}?
  }

state =

  element state {
    viewContent
  & attribute apply {boolean}?
  & ## If pooling is true, views that are created by the state are not
    ## destroyed when the state is removed -- instead they just act
    ## as if they were by sending the onremovesubview event and setting
    ## their visibility to false.
    [a:since="1.1"
     a:defaultValue="false"]
    attribute pooling {boolean}?
  & ## Script that is executed when the state is applied to its parent.
    attribute onapply {script}?
  & ## Script that is executed when the state is removed from its parent.
    attribute onremove {script}?
  }

nodeAttributes = (
  objectAttributes,
  ## The view in which a child is placed by default
  attribute defaultplacement {string}?
)

nodeElements =
    objectElements
  & datapathChildren
  & element data {
     datasetAttributes & anyXML
  }*
  & element dataset {
     datasetAttributes & anyXML
  }*
    
nodeContent =
    nodeAttributes &
    nodeElements

node =

  element node {nodeContent}

datarequest = 
   element datarequest {nodeContent}

layout = 

  element layout {
    nodeContent &
    attribute locked {booleanLiteral}?
  }

#
# Application Configuration
#
splash =
  element splash {
     [lza:visibility="private"]
      attribute hideafterinit {booleanLiteral}? &
      [a:defaultValue="false"]
      attribute persistent {booleanLiteral}? &
      [lza:name="splash view"]
      element view {
        attribute name {token}? &
        attribute resource {xsd:anyURI} &
        attribute ratio {xsd:string}? &
        [a:defaultValue="0"]
        attribute x {numberLiteral}? &
        [a:defaultValue="0"]
        attribute y {numberLiteral}? &
        [a:defaultValue="false"]
        attribute center {booleanLiteral}?
      }*
  }

scriptElement =
  element script {
    ## The pathname of a JavaScript file.  This pathname is resolved
    ## relative to the file that contains the <tagname>script</tagname>
    ## element.
     [a:defaultValue="Javascript" lza:modifiers="final"]
     attribute type {xsd:string}? &
     [a:defaultValue="normal" lza:modifiers="final"]
     attribute when {"normal" | "immediate" }? &
     (attribute src {xsd:anyURI} | text?)
  }

styleSheetElement =
 element stylesheet {
  (## The pathname of a css file.  This pathname is resolved
   ## relative to the file that contains the <tagname>stylesheet</tagname>
   ## element.
    attribute src {xsd:anyURI} 
  | text?)
}


preloadresource = 
 element preloadresource {
     attribute name {token}? &
     attribute ratio {string}? &
     attribute synctoload {booleanLiteral} &
     attribute hideafterinit {booleanLiteral} &
     attribute center {booleanLiteral} &
     attribute synchronized {booleanLiteral}? &
     attribute lastframe {numberLiteral}? & 
     attribute resource {string}? &
     attribute resourcename {string}? &
     viewAttributes
}


#
# Security
#
pattern = element pattern { text }
allow   = element allow { pattern* }
deny    = element deny  { pattern* }
security = element security {
      allow?
    & deny?
}