[Bug] Webdialog callback has trouble handling special characters, even when escaped

Developers Ruby API
1

Hi,

I’m using a comment callback to add a comment from a web dialog to an item in my Plugin. Since special characters might be possible, I use the javascript function encodeUriComponent(str) to encode those characters.

For example, when I use skp:comment@107%3Dit's (which is skp:comment@107=it's) Sketchup crashes immediately, even if the callback is empty:

Error: #<SyntaxError: <main>: syntax error, unexpected tIDENTIFIER, expecting ')'
('107=it's')
         ^
<main>: unterminated string meets end of file
<main>: syntax error, unexpected end-of-input, expecting ')'
('107=it's')

It does work in the normal irb console:

ruby -v
ruby 2.0.0p247 (2013-06-27) [i386-mingw32]
irb(main):001:0> require 'uri'
=> true
irb(main):002:0> URI.unescape("skp:comment@107%3Dit's")
=> "skp:comment@107=it's"

When I escape the value according to RFC3986, which escapes ' too: skp:comment@107%3Dit%27s, I get the same error.

2

there’s a thread which includes a test script I posted at SCF a couple of years ago…

CLICK HERE

700×600 36.3 KB

john

3

Doesn’t work at all with '

694×571 12.5 KB 

Error: #<SyntaxError: <main>: syntax error, unexpected tIDENTIFIER, expecting ')'
('lid1,it's a bugger')
           ^
<main>: unterminated string meets end of file
<main>: syntax error, unexpected end-of-input, expecting ')'
('lid1,it's a bugger')
                      ^>
SketchUp:1:in `eval'
Error: #<NoMethodError: undefined method `split' for nil:NilClass>
C:/Users/spe.ST-DEVELOPMENT/AppData/Roaming/SketchUp/SketchUp 2016/SketchUp/Plugins/show_encoding_issue.rb:113:in `block in show_problem'
SketchUp:1:in `call'
Error: #<SyntaxError: <main>: syntax error, unexpected tIDENTIFIER, expecting ')'
('lid1,it's a bugger')
           ^
<main>: unterminated string meets end of file
<main>: syntax error, unexpected end-of-input, expecting ')'
('lid1,it's a bugger')
                      ^>
SketchUp:1:in `eval'
Error: #<NoMethodError: undefined method `split' for nil:NilClass>
C:/Users/spe.ST-DEVELOPMENT/AppData/Roaming/SketchUp/SketchUp 2016/SketchUp/Plugins/show_encoding_issue.rb:96:in `block in show_problem'
SketchUp:1:in `call'

I’m on Windows 10, 64bit

4

The ’ nested within a string delimited by ’ is taken as the end of the enclosing string. You need to escape the ’ in it’s.

5

I already tried that. Sketchup is using the unescaped value internally, my callback method is empty.

6

Because the callback always encloses its string within single-quotes you must escape any ' within the passed string.
e.g. in your it's the single-quote needs escaping, so you might think that "it\'s" would work, BUT when passing it to the callback you also need to escape the \ escape character itself !
So pass it as "it\\\'s"

Simply process the passed string through a replace function, so every ' becomes \\\'

string = "it's";
formattedString = string.replace(/'/g, "\\\'");

formattedString >>> "it\\\'s"

Which survives the callback process…
Arriving as it's

7

It seems my old test file fails depending on a straight or curly apostrophes…

in your snippet the apostrophe is not escaped using encodeUriComponent(str)…

that may be the same underlaying issue…

john

8

Yes. I’m aware of that. Which is why I tried using an extended version of encodeUriComponent that escapes it's as it%27s. it%27s fails too.

Yes, rfc2396 (which URI.unescape is based on) doesn’t escape !, ', (, ), and *. Those characters can be escaped with a custom method like

function fixedEncodeURIComponent (str) {
  return encodeURIComponent(str).replace(/[!'()*]/g, function(c) {
    return '%' + c.charCodeAt(0).toString(16);
  });
}

But it appears to me that Sketchup itself can’t handle such a string, as it somewhere internally probably uses URI.unescape and encloses the result with ' at a later point which then crashes.

Yes, I can write my own escaping, that is not accidentally unescaped by Sketchup, but this doesn’t seem right to me.

9

Did you actually try skipping your own encoding trickery and simply using the ‘replace’ code example which I provided.
I find that it works for me just fine…
You saying that your method doesn’t work, is NOT the same as saying that mine is flaky !

Another alternative would be to replace the ’ characters in the string with ` in js, before the callback sends the string.
Then on the Ruby-side you can choose to either accept that back-quote or tr it into a ’ ?
If you never expect the back-quote then swapping to a ’ is OK ??

10

Not at work right now, but will do it tomorrow. I’m sure it’ll work, but why is that not a bug nonetheless? I’m not doing encoding trickery, Sketchup is and it fails while doing it. **I’m sending it%27s to a callback and Sketchup decides to unescape it in an unsafe/incorrect manner and fails. **