how encoding & decoding works in grails with decodeHTML & encodeAsHTML in grails?

Question

I am trying to understand how encoding & decoding works in grails with decodeHTML & encodeAsHTML

// decode Example is

List symbols = ['!', '*', '/']
symbols.each { String symbol ->
    println symbol.decodeHTML()
}

it should print

!    // but it prints !
*   // but it prints *
/   // but it prints /

// encode Example is

List symbols = ['!', '*', '/']
symbols.each { String symbol ->
    println symbol.encodeAsHTML()
}

it should print

'!'  // but it prints !
'*'  // but it prints *
'/'  // but it prints /

Solution

escapeAsHtml end up calling StringEscapeUtils.escapeHtml in apache commons lang

As it says in the docs for that method;

Escapes the characters in a String using HTML entities.

For example:

"bread" & "butter"

becomes: "bread" & "butter".

Supports all known HTML 4.0 entities, including funky accents. Note that the commonly used apostrophe escape character (') is not a legal entity and so is not supported).

It does not convert all characters to their entity value, so things like !, * and / are left as-is. Here's an example in Groovy:

@Grab( 'commons-lang:commons-lang:2.6' )
import static org.apache.commons.lang.StringEscapeUtils.escapeHtml

'!@£$%^&*()_+€-={}[]:"|;\'\\<>?,./~'.each {
    println "$it -> ${escapeHtml( it )}"
}

That prints:

! -> !
@ -> @
£ -> £
$ -> $
% -> %
^ -> ^
& -> &
* -> *
( -> (
) -> )
_ -> _
+ -> +
€ -> €
- -> -
= -> =
{ -> {
} -> }
[ -> [
] -> ]
: -> :
" -> "
| -> |
; -> ;
' -> '
\ -> \
< -> &lt;
> -> &gt;
? -> ?
, -> ,
. -> .
/ -> /
~ -> ~

Comments

[Ivar]

"escapeAsHtml" Don't you mean encodeAsHTML? And if so you sure that it ends up calling StringEscapeUtils.escapeHtml? Because when I print this: "\"café\"".encodeAsHTML() it ends up as "café", while if I use StringEscapeUtils.escapeHtml("\"café\"") it ends up as "café". (It escapes the é as well.)