Develop Reference

How do I use twitter-text in a browser

I want to count tweet length. Twitter makes this very very hard.
They have this repo: https://github.com/twitter/twitter-text which contains this folder: https://github.com/twitter/twitter-text/tree/master/js which supposedly supports javascript.
When I try to use the script from a cdn like this: https://www.jsdelivr.com/package/npm/twitter-text
it says require is not defined
I don't understand what I'm supposed to do. Why is it using require if it's for javascript?

Install Browserify
Download the latest twitter-text script from this folder: https://github.com/twitter/twitter-text/tree/master/js/pkg
Create index.js with the contents: window.twitter = require('./twitter-text-3.1.0.min.js');
Run browserify index.js -o twitter-text-js.js
The output file can now be run in browser and accessed with the global twitter.
(or just download the prepackaged version here: https://gist.github.com/skeddles/3841236279efebf053dfa39dfdbae2c2#file-twitter-text-js-js)

tern.js not loading three.js plugin

Problem
I'm currently trying to build a 3D web app based on three.js.
I'm using neovim as my development environment and YouCompleteMe as a completion system.
I installed tern to complete JS, and I added .tern-project file like this.
{
"libs": [
"browser",
"ecmascript",
],
"loadEagerly": [
],
"plugins": {
"threejs": {}
}
}
I also copied threejs.js and threejs.json to my project's directory generated by tern-threejs.
However, YouCompleteMe doesn't show semantic completion compared to tern-threejs's demo codemirror
Comparison:
codemirror:
neovim:
Note: I can't see any completion at all.
What seems to be the problem?

threejs.js is a tern plugin file and threejs.json is a tern library file. plugin files should be copied in tern/plugin directory and library files needs to be placed within tern/defs directory. These two directory exists within tern directory.
With 'YouCompleteMe' installed this dir path is: ~/.vim/YouCompleteMe/third_party/ycmd/third_party/tern-runtime/node‌​_modules/tern. You only need to copy one of aforementioned files. Plugin file or lib file; and update your .tern-project file accordingly. so:
First ensure that you have enabled the Tern completer on YouCompleteMe. For example on my Mac, I had to run the following:
cd ~/.vim/bundle/YouCompleteMe
./install.py --tern-completer
See YouCompleteMe installation guide for details on how to do it on other environments.
Copy threejs.js then navigate to
~/.vim/YouCompleteMe/third_party/ycmd/third_party/tern-runtime/node‌​_modules/tern/plugin/
and paste.
Update your project's .tern-project file as follows:
{
"libs": [
"browser",
"ecmascript",
],
"plugins": {
"es_modules": {},
"threejs": {}
}
}
Note that i've also included es_modules plugin (which is a plugin shipped with tern itself) as you are using ES6 module pattern system.

Writing a git post-commit file in node.js

I'm trying to write a git post-commit file in node.js and I'm having trouble.
The file seems to have to be named post-commit in the .git/hooks directory. Since that file can't have an extension, my vim editor won't persistently give it javascript syntax highlighting, and thus none of my snippets work, and a variety of other challenges present themselves.
What can I do? Tell git to run post-commit.js or tell vim to consider this file javascript, but that doesn't persist.
Thoughts?

You can have the post-commit file run a separate JavaScript file.
post-commit:
#!/bin/bash/
node yourJavascriptFile.js

Use :set filetype=javascript command in vim to set file type.
You may also want to enable modeline in vim and include the aforementioned command in a comment at the top of your file like this:
/* vim: set filetype=javascript : */
your_Javascript_code_goes_here()
To enable modeline in vim, add this to your ~/.vimrc file:
set modelines=2
set modeline
That will enable searching for vim modelines in the first two lines of the file.

Method completion for AngularJS in Atom.io

When using Atom.io for writing AngularJS I'd like to get code-completition for the AngularJS services such as $log. That is to see the list of methods $log provides when I type a . after it.
Which plugin do I need for that?
Do I need to make some configuration for that to work?
I already have the following Atom.io packages installed:
angularjs, atom-ternjs, and turbo-javascript which seems to provide the above functionality for JavaScript, but not the special AngularJS methods.

You should be able to use the AngularJS plugin for TernJS which has shipped with recent versions of tern:
Ensure you have the TernJS package installed:
apm install tern
Open your project and, open the Command Palette with Ctrl-Shift-P.
Type tern openconfig and press Enter.
Click Save & Restart Server at the bottom of the resulting tab.
Your .tern-project will be loaded as a new tab.
Add the following snippet to your .tern-project
"plugins": {
"angular": "./"
}
So that it looks like this:
{
"ecmaVersion": 6,
"libs": [],
"plugins": {
"angular": "./"
}
}
Save the .tern-project
Once again open the Command Palette with Ctrl-Shift-P.
Type tern restart and press Enter to restart the tern server.

Whilst not specific to AngularJS, perhaps autocomplete-plus can help you with this.

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.