Scratch

technoboy10 wrote:

Here's my (rough) plan for executable Snap! extension servers.

That's all fine, but the key point is that you have to be able to inject the corresponding .xml into Snap! itself.  And this has to work even if the user is running two or more extensions at once.  So, your program has to be a web server itself, like the extensions, and when you click its "Start Snap!" button, it has to send to the user's browser the URL

http://snap.berkeley.edu/snapsource/snap.html#open:http://localhost:3986?extendme

where 3986 is the assigned port for your program itself, and "extendme" is interpreted by your server to mean "concatenate the XML files for all the chosen extension modules" (probably not quite literally concatenate; you have to have just one XML wrapper for the whole thing).

It would be even better if this could be done from within Snap!, so that an extension module could be added easily to an already-running Snap! instance, but Jens questions whether we should have that degree of smooth connection because the user should know that s/he is doing something that breaks the Javascript sandbox.  He's probably right.  In fact your program's menu should say in red up at the top "External Snap! extensions do not have the same assurance of safety as Snap! itself.  Use extension modules only from sources you trust."

blob8108 wrote:

So, for example, I can convert a Snap! variable to a Scratch list if you use list blocks on the variable. This won't work for all cases, but I think I can raise warnings for most of them.

You mean, "if you use only list blocks on" it.  But consider the situation in which a variable is assigned a value that's reported by a custom block, and that custom block reports a list.  And the variable itself is merely passed as input to other custom blocks, so it's never used with a list primitive.

PS I hate when I wake up in the morning and there are a zillion posts and when I answer the first one my answer starts a new page, and I have to keep switching back and forth!  (But I do like waking up to a zillion posts!)

blob8108 wrote:

Scratch 2.0 doesn't have reporter blocks, so that's already a failure 

Oh yeah huh.  That's the other problem about finding a zillion posts when I wake up! 

But you have to plan ahead for 2.1 or whatever they call the version that does. 

Zygorithm wrote:

I keep getting an invalid syntax error.

Did you install Python 2.7?

technoboy10 wrote:

I've had to learn how to multi-quote just because of this thread. 

You know that you can just say [quote] rather than [quote=foo] after the first time, right?

About open=this&that, we'll see what Jens thinks, but there's so much else going on in Snap! itself right now that if you can have an entirely self-sufficient program it'd be up for users much sooner.

Zygorithm wrote:

The project ID is the number at the end of the URL to the file.

For help, type "python snapin8r.py -help".

Remember to cd into the snapin8r directory!

I keep getting an invalid syntax error. I typed "python snapin8r.py number", "python snapin8r.py -number", and "python snapin8r.pynumber" and none of them work.

That's strange… can you paste the entire output?

EDIT: It shouldn't be just number, it should be:

python /path/to/snapin8r.py -p number -f /full/path/to/desired/output/file.xml -open

Use -f and -open are optional flags (-open automatically opens Snap! with the converted project). -p is required.

You should have gotten:

The -p flag is mandatory. Run './snapin8r.py -help' for help on flags.

if you didn't add the -p flag… 

Last edited by Hardmath123 (2013-04-04 23:44:42)

Zygorithm wrote:

Code:

python /path/to/snapin8r.py -p number -f /full/path/to/desired....

I still get an invalid syntax error. Here's what I did.
https://dl.dropbox.com/u/45677595/SyntaxError.png

It's because you're using Python version 3.3. You'll need to download Python 2.7 instead. 

Zygorithm wrote:

I notice Snap! doesn't have a permanent list block. How do I store my permanent databases such as stats, bag items, party list, save states, etc?

Make a variable, assign it a list value.

The big idea:  Binding a name to a value is a single capability, regardless of the type of value.  A special make-a-list button is no more necessary than a make-an-integer button.

(Yes, I know, in principle this argument applies just as well to the make-a-block button.  But blocks have all these special properties -- shape, color, inputs, all that -- and have to appear in the palette.  I've always wanted the variable blocks to turn into command, reporter, or predicate shape when the variable is given a procedure as its value, but the trouble, as Jens keeps reminding me, is that the variable assignment doesn't happen until too late to put that block in a script.)

Ok now I'm getting a new error during run time.
KeyError: u'startScene'
https://dl.dropbox.com/u/45677595/SyntaxError.png

Hardmath123 wrote:

As for the startScene error, Snap! doesn't support the Scene blocks so you can't convert projects that use those. Sorry.

Sounds like your error messages need work! 

Wow, nice video! I really think you did a nice job with it.    I like that you included a few "try doing this yourself" moments and you explained everything at a good pace.

Thanks.  The scary part is, at 10 min/video I'm going to have to do 20-30 more like it, to cover everything in the manual.

As for the startScene error, Snap! doesn't support the Scene blocks so you can't convert projects that use those. Sorry.

My project does not use any Scene blocks. It was converted from Scratch 1.4 and I did not use any Scratch 2.0 features like Scene, clone, cloud variables, etc.