Add IFRAME class for <iframe> html tags

Author: d-torrance

M2/Macaulay2/m2/content.m2

@@ -54,7 +54,7 @@ BlockExtra = set {}
 ---<!ENTITY % Form.class  "| %form.qname;" >
 ---<!ENTITY % Fieldset.class  "| %fieldset.qname;" >
 ---<!ENTITY % BlkSpecial.class "%Table.class; %Form.class; %Fieldset.class;" >
-BlkSpecial = set { "table", "form", "fieldset" }
+BlkSpecial = set { "table", "form", "fieldset", "iframe"}
 
 -- <!ENTITY % Blkpres.class "| %hr.qname;" >
 ---<!ENTITY % BlkPres.class "| %hr.qname;" >
@@ -109,6 +109,7 @@ validContent = new MutableHashTable
 -----------------------------------------------------------------------------
 -- <!ENTITY % dd.content "( #PCDATA | %Flow.mix; )*" >
 validContent#"dd" =
+validContent#"iframe" =
 -- <!ENTITY % li.content "( #PCDATA | %Flow.mix; )*" >
 validContent#"li" = 
 -- <!ENTITY % div.content "( #PCDATA | %Flow.mix; )*" >

M2/Macaulay2/m2/hypertext.m2

@@ -133,6 +133,7 @@ DIV        = new MarkUpType of HypertextContainer
 BR         = new MarkUpType of HypertextVoid
 HR         = new MarkUpType of HypertextVoid
 SCRIPT     = new MarkUpType of HypertextParagraph
+IFRAME     = new MarkUpType of HypertextContainer
 
 -- Headers
 HEADER1    = new MarkUpType of HypertextParagraph
@@ -372,6 +373,9 @@ addAttribute(TH,     htmlAttr | {"colspan", "headers", "rowspan"})
 addAttribute(IMG,    htmlAttr | {"alt", "src", "srcset", "width", "height",
 	"sizes", "crossorigin", "longdesc", "referrerpolicy", "ismap", "usemap"})
 addAttribute(OL, htmlAttr | {"start"=>"0", "reversed", "type"})
+addAttribute(IFRAME, htmlAttr | {"allow", "allowfullscreen",
+	"allowpaymentrequest", "height", "loading", "name", "referrerpolicy",
+	"sandbox", "src", "srcdoc", "width"})
 buttonAttr = htmlAttr | {"autofocus","disabled",
     "form","formaction","formenctype","formmethod","formnovalidate","formtarget",
     "name", "type", "value"}

M2/Macaulay2/packages/Text.m2

@@ -9,7 +9,7 @@ newPackage("Text",
 
 exportFrom_Core {
      "ANCHOR", "BLOCKQUOTE", "BODY", "BOLD", "BR", "CDATA", "CODE", "COMMENT", "DD", "DIV", "DL", "DT", "EM", "ExampleItem", "HEAD", "HEADER1",
-     "HEADER2", "HEADER3", "HEADER4", "HEADER5", "HEADER6", "HR", "HREF", "HTML", "Hypertext", "HypertextContainer", "HypertextParagraph", "HypertextVoid", "IMG", "INDENT", "ITALIC", "KBD",
+     "HEADER2", "HEADER3", "HEADER4", "HEADER5", "HEADER6", "HR", "HREF", "HTML", "Hypertext", "HypertextContainer", "HypertextParagraph", "HypertextVoid", "IFRAME", "IMG", "INDENT", "ITALIC", "KBD",
      "LABEL", "LATER", "LI", "LINK", "LITERAL", "M2CODE", "MENU", "META", "PARA", "PRE", "SAMP", "SCRIPT", "SMALL", "SPAN", "STRONG", "STYLE", "SUB", "SUBSECTION", "SUP", "TABLE", "TD", "TH",
      "TEX", "TITLE", "TO", "TO2", "TOH", "TR", "TT", "UL", "VAR", "OL", "INPUT", "BUTTON", "validate",
      "MarkUpType", "IntermediateMarkUpType",
@@ -855,6 +855,19 @@ document {
      "For an example, see ", TO "Macaulay2Doc::hypertext list format", "."
      }
 
+document {
+    Key => {IFRAME},
+    Headline => "HTML inline frame (iframe) element",
+    Usage => "IFRAME x",
+    Inputs => {"x" => List => "specifying the iframe attributes"},
+    PARA {
+	"An ", M2CODE "IFRAME", " object represents an inline frame in HTML, ",
+	"which allows embedding an independent browsing context (another HTML ",
+	"document) within the current one."},
+    EXAMPLE "html IFRAME {\"src\" => \"https://example.com\"}",
+    PARA {"This is rendered in the browser as:"},
+    IFRAME {"src" => "https://example.com"}}
+
 document { Key => (options, MarkUpType),
      "Optional arguments of mark up types allow attributes to be added to html elements.",
      EXAMPLE lines ///