Develop Reference

minifying javascript messes up characters

I am trying to minify a .js file that includes code like this:
DIACRITICS = {"\u24B6":"A","\uFF21":"A","\u00C0":"A","\u00C1":"A","\u00C2":"A","\u1EA6":"A","\u1EA4":"A","\u1EAA":"A","\u1EA8":"A","\u00C3":"A","\u0100":"A","\u0102":"A","\u1EB0":"A","\u1EAE":"A","\u1EB4":"A","\u1EB2":"A","\u0226":"A","\u01E0":"A","\u00C4":"A","\u01DE":"A","\u1EA2":"A","\u00C5":"A","\u01FA":"A","\u01CD":"A","\u0200":"A","\u0202":"A","\u1EA0":"A","\u1EAC":"A","\u1EB6":"A","\u1E00":"A","\u0104":"A","\u023A":"A","\u2C6F":"A","\uA732":"AA","\u00C6":"AE", ....
The problem is, when I use a tool like http://javascript-minifier.com/ or http://refresh-sf.com/ to minify it, the above code gets changed to this:
,j={"Ⓐ":"A","Ａ":"A","À":"A","Á":"A","Â":"A","Ầ":"A","Ấ":"A","Ẫ":"A","Ẩ":"A","Ã":"A","Ā":"A","Ă":"A","Ằ":"A","Ắ":"A","Ẵ":"A","Ẳ":"A","Ȧ":"A","Ǡ":"A","Ä":"A","Ǟ":"A","Ả":"A","Å":"A","Ǻ":"A","Ǎ":"A","Ȁ":"A","Ȃ":"A","Ạ":"A","Ậ":"A","Ặ":"A","Ḁ":"A","Ą"
I assume that will cause problems when it executes? Is there any way around this?

Try using Microsoft's AjaxMinifier: http://ajaxmin.codeplex.com/
This is to do with encoding, so use the program with the "-enc:out ascii" command.
Once you download the program, open it. It will appear like a command prompt window. CD to the directory of your JS file, then run:
ajaxminifier file.js -o file.min.js -enc:out ascii

IO Error in d3py example code -- no such file or directory: 'static/d3.js'

I am trying to run through the d3py example code available in the d3py readme file (see link below), and am receiving the following error:
https://github.com/mikedewar/d3py/blob/master/README.md
(python 2.7.3 on 32-bit Windows)
>>> # instantiate the figure object
>>> fig = d3py.Figure(df, name="basic_example", width=300, height=300)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "build\bdist.win32\egg\d3py\d3py.py", line 97, in __init__
IOError: [Errno 2] No such file or directory: 'static/d3.js'
>>>
I installed the d3py package by using the following command in PowerShell:
easy_install https://github.com/mikedewar/d3py/tarball/master
and, importing the package within a python session (i.e. import d3py) does not result in any errors. What can I do to make the example code work?

So d3py is a really raw project, and to be honest our setup.py sucks quite hard. This means you either need to make a pull request with some fixes to setup.py or you need to make a folder called static in your project folder and make sure that d3.js is inside the folder.
On the assumption that the second option is the one you'll use, just to make it clear:
In a terminal, change to the directory that holds your project, like
cd ~/Desktop/my/awesome/project
Make a folder called static:
mkdir static
then move into that directory and get the d3.js file from the repo:
cd static
curl -O https://raw.github.com/mikedewar/d3py/static/d3.js
Apologies for this terrible hack! d3 based plotting from inside python is definitely going to happen, but maybe not with this project!
Having said that, d3py will work as advertised once you get it to run! A really popular use case of d3py, which we hadn't quite realised would be popular, is that people use it to quickly mock up some javascript, using the output of d3py as a starting point for fancier visualisations.

Python and the Spidermonkey Javascript engine on Linux

I have successfully installed Spidermonkey JS engine on my Linux machine ( Ubuntu ).
Basically my goal is to make it execute Ajax (js) scripts and return the result back to my Python script. I'm basically trying to build a good O.O. web scraper. But it's pretty hard for me to get all of this working.
I'm now at the point where when I type JS in my terminal I can start executing Javascript.
I've been Googling and found this little snipet on Stackoverflow :
import urllib2
import spidermonkey
js = spidermonkey.Runtime()
js_ctx = js.new_context()
script = urllib2.urlopen('http://etherhack.co.uk/hashing/whirlpool/js/whirlpool.js').read()
js_ctx.eval_script(script)
js_ctx.eval_script('var s="abc"')
js_ctx.eval_script('print(HexWhirpool(s))')
but it failed to run with the error that module Spidermonkey can not be found.
I'm a bit lost now. Anyone able to help?

I also tried easy_install python-spidermonkey with no luck, for libnspr-dev package is absent.
So, I've built package from source. Instructions from project page (Debian Stretch):
Building
Check out the Python-Spidermonkey module from the SVN repository ( I downloaded it as source archive, direct link )
Unpack, and cd to ./python-spidermonkey/trunk
CPPFLAGS="-Wno-format-security" python setup.py build (these flags for Debian)
Error jsemit.h:508:32: error: expected ‘(’ before ‘)’ token uintN decltype); means that decltype cannot be used as variable (maybe it's a macro or something else), fix it this way:
sed -e 's/decltype/dectyp/' -i.ORIG ./js/src/jsemit.h
sed -e 's/decltype/dectyp/' -i.ORIG ./js/src/jsemit.cpp
Error jsemit.cpp:6490:1: error: narrowing conversion of ‘-1’ from ‘int’ to ‘uint8 {aka unsigned char}’ inside { } [-Wnarrowing] means illegal variable conversion, recompile it manually:
cd js/src
g++ -o Linux_All_DBG.OBJ/jsemit.o -c -Wall -Wno-narrowing -Wno-format -MMD -g3 -DXP_UNIX -DSVR4 -DSYSV -D_BSD_SOURCE -DPOSIX_SOURCE -DHAVE_LOCALTIME_R -DHAVE_VA_COPY -DVA_COPY=va_copy -DPIC -fPIC -DDEBUG -DDEBUG_user -DEDITLINE -ILinux_All_DBG.OBJ jsemit.cpp
Error spidermonkey.c:1:2: error: #error Do not use this file, it is the result of a failed Pyrex compilation. - some trouble with pyrex. There is a patch. Do it this way:
wget -O - https://storage.googleapis.com/google-code-attachments/python-spidermonkey/issue-14/comment-4/cinit.patch | patch -p1 ./spidermonkey.pyx
Installation
su, and python setup.py install as root.
Running
By default, setup script installs libjs.so to /usr/local/lib/, so I did ln -s /usr/local/lib/libjs.so /usr/lib/libjs.so (but you'd better use solution from Seagal82)
Without this step, python keeps complaining about import ImportError: libjs.so: cannot open shared object file: No such file or directory
I also had an error ImportError: cannot import name Runtime after from spidermonkey import Runtime. The reason possibly was in old easy_install data in ~/.local/lib/python2.7/site-packages/spidermonkey/. After removing it, all runs smooth

Recently i got a task need to do something like Web scraping,
and for the javascript part, currently want to try using python-spidermonkey to resolve it and see if this might work for me ...
and i seem to meet situation might alike, after i think i finished install python-spidermonkey, i execute the script above, i got this error:
Traceback (most recent call last):
File "spidermonkeytest.py", line 2, in <module>
import spidermonkey
ImportError: libjs.so: cannot open shared object file: No such file or directory
then after some searching by google...i found the solution probably in the end of here:
http://hi.baidu.com/peizhongyou/item/ec1575c3f0e00e31e80f2e48
i setup these things:
$sudo vi /etc/ld.so.conf.d/libjs.so.conf
fill in this line:
/usr/local/lib/
save & exit, execute ldconfig:
$sudo ldconfig
then i can run the script provided above by #Synbitz Prowduczions
don't know if this is the answer you need, or this still helps?

You need to try libnspr4. If that doesn't work, you can always download it from Mozilla and build the code yourself.
It is not difficult to type ./config && make && make install to build the library yourself after untarring the source. If you build yourself, files will likely be in
/usr/local/{include,lib}
Also just try Googling for "YOUR_OS_NAME install nspr4".
I believe someone wrote a C/C++ header file translator for Python ctypes. Although I can't say much else because I don't use Python.
SpiderMonkey also has its own implementation of ctypes modeled after Python. So technically if you know javascript you could forego using Python altogether since you want to do some ajax with it. You will need to brush up on the NSPR or C runtime sockets to meet the requirements for your projects using only Spidermonkey.
OR a web search for Python +AJAX might turn up exactly what you need.

doctorjs(aka jsctags) not work with vim+tagbar

I am using windows 7 64bit...
I've installed nodejs 0.6.11 by MSI installer, the installation path is "C:\Program Files (x86)\nodejs", it was automatically added to my %PATH% by the installer, I installed doctorjs by steps below:
I copied doctorjs files under "C:\Program Files (x86)\nodejs\doctorjs"
I created jsctags.cmd filled with content copied from https://gist.github.com/1438882
I added following lines in my _vimrc:
let g:tagbar_type_javascript = {
\ 'ctagsbin' : 'C:\Program Files (x86)\nodejs\jsctags.cmd'
\ }
The problem is, when I run jsctags.cmd "{My js folder}", it generates tags file with only content below:
!_TAG_FILE_FORMAT 2 /extended format/
!_TAG_FILE_SORTED 0 /0=unsorted, 1=sorted, 2=foldcase/
!_TAG_PROGRAM_AUTHOR Patrick Walton /pwalton#mozilla.com/
!_TAG_PROGRAM_NAME jsctags //
!_TAG_PROGRAM_URL http://github.com/pcwalton/jsctags /GitHub repository/
!_TAG_PROGRAM_VERSION 0.1 //
And when I run :tagbaropen in vim, it shows nothing for current js file..
Please kindly guide me where I did wrong, thank you!

Since you're getting some output, it looks like you have the gist implemented correctly. But maybe your expectation of how to use it at a command line is different than the way it really works?
FYI: jsctags.cmd "{my js folder}" returns an empty tags file on my machine too. I don't think the command interface is very mature yet... so it looks like creating a tagfile of a whole folder is not possible - yet...
Try jsctags.cmd "{file}". This should create a populated tag file.
Also note that tagbar calls jsctags like this: jsctags -f - {file}. This streams the output to stdout. So if you're debugging, try this form of the command.
As another debugging tip, modify your batchfile to output debugging info. ie:
Add lines like this:
echo "%~dp0"\"node.exe" "D:\opt\node\doctorjs\bin\jsctags.js" %* > d:\debug.txt
Looking in d:\debug.txt will let you see what the command looks like as it is called from tagbar.
BTW: The gist you're using was mine... I am wondering if I didn't test this batch file well enough with folders that have spaces in them. Do some tests in both folders with and without spaces to see if there is a difference. If you get more insight into where it works/doesn't, let me know and I can investigate further.

Your issue might be related to the commit of narcissus you've cloned for doctorjs. Go into the narcissus folder in the doctorjs folder and run
git checkout 4ae5aff8b3
This should switch the head to the proper version of the file.

Where to place JS files for NodeJS to see them

I've just installed NodeJS on my Mac, and i got it working in the terminal, using inline scripting like "console.log('Hello world'); works fine.
But where do i place JS files for NodeJS to find them? Can i specify the root folder NodeJS to look for file in?
I followed this guide: http://nodeguide.com/beginner.html#learning-javascript
but i cannot get any of the samlpe to work where i reference a script file.

You put them in whatever folder you want. It is common practice to put each application in a different folder.
Then you run node.js like this:
node /path/to/file.js
Or like this:
cd /path/to/
node file.js
Where file.js might look something like this:
console.log('hello world');

You'll have to navigate to the correct folder "manually", in the Node Command Line Interface (CLI).
If you need to change drives, type the drive letter and a colon to switch to that drive, like so;
C:> (<- this is the line prompt, yeah? Just add this after it -> D:
That changes the drive. Now write cd (CD = "Change Directory") and the name of the direcotry you want to go to the directory your stuff is in:
D:> (<- the new prompt. Write something like this after it: ->) cd myprosject\subfoldername
D:\myproject\subfoldername> (<- your new line prompt - if "myproject\subfoldername" exists)
now ask node to execute your script (that is stored in myproject\subfoldername, like so;
D:\myproject\subfoldername> node helloworld.js
Remember to write "node" first - otherwise the command won't go to node, but to the OS, which will probably just open up the js file in a text editior instead of running the goodies inside.

It is very easy.. Go to your command line. navigate to the file location..
then simply run the node helloworld.

I'm not sure I understand. it doesnt 'look' anywhere for your .js files you point at them when you run node. Like so, on the command line:
node mynodeapp.js
If you're meaning where does it look for your .js files as modules, when requirign them, like so:
var mymodule = require("mymodule");
Then it will look inside a folder names node_modules. But I'm sure you're looking for my first example above.