How convert a String to HTML Entity Codes?

I think, the $zconvert() function will cover only the necessary entities. But you can use a simple method to convert characters to currently known(*) entities.

ClassMethod ToHTML(str)
{
   for i=$length(str):-1:1 set c=$ascii(str,i) set:$data(^entityChars(0,c),c) $extract(str,i)=c
   quit str
}

ClassMethod FromHTML(str)
{
   set i=0
   while $locate(str,"&[A-Za-z]+;",i,j,v) {
   set:$data(^entityChars(1,v),c) s=$length(v), $extract(str,j-s,j-1)=$c(c), j=j-s+1
   set i=j
   }
   quit str
}

I have a table (the ^entityChars() global) which contains more the 1400 entities. You can download the above class, together with the table from my FTP server (File: DC.Entity.xml):

Adr: ftp.kavay.at
Usr: dcmember
Psw: member-of-DC

A sample output:

USER>write ##class(DC.Entity).ToHTML("Flávio Lúcio Naves Júnior")
Flávio Lúcio Naves Júnior
USER>write ##class(DC.Entity).FromHTML("Flávio Lúcio Naves Júnior")
Flávio Lúcio Naves Júnior

(*) Currently known, because (1) I do not have all the currently known entities in my table and (2) with each new day, the W3C and the Unicode consortium can extend the current entity list.