Source code for pyquickhelper.imghelper.js_helper

Helpers around images and :epkg:`javascript`.
See also:

* `pyduktape <>`_
* `Python Mini Racer <>`_
* `python-requirejs <>`_

.. versionadded:: 1.7

import os
from ..loghelper import run_cmd, noLOG

[docs]class NodeJsException(Exception): """ Raised if :epkg:`node.js` fails. :githublink:`%|py|19` """ pass
[docs]def run_js_fct(script, required=None): """ Assuming *script* contains some :epkg:`javascript` which produces :epkg:`SVG`. This functions runs the code. :param script: :epkg:`javascript` :param required: required libraries (does not guaranteed to work) :return: :epkg:`python` function The module relies on :epkg:`js2py` and :epkg:`node.js`. Dependencies must be installed with :epkg:`npm`:. :: npm install babel-core babel-cli babel-preset-es2015 babel-polyfill babelify browserify babel-preset-env Function :func:`install_node_js_modules <pyquickhelper.imghelper.js_helper.install_node_js_modules>` can be run with admin right for that. :epkg:`js2py` tries to convert a dependency into :epkg:`Python` :githublink:`%|py|42` """ from js2py import eval_js, require, node_import # pylint: disable=W0621 # To skip npm installation. node_import.DID_INIT = True if required: if not isinstance(required, list): required = [required] for r in required: require(r) fct = eval_js(script) return fct
[docs]def install_node_js_modules(dest, module_list=None, fLOG=noLOG): """ Installs missing dependencies to compile a convert a :epkg:`javascript` libraries. :param dest: installation folder :param module_list: list of modules to install :param fLOG: logging function If *module_list is None*, it is replaced by: :: ['babel-core', 'babel-cli', 'babel-preset-env', 'babel-polyfill', 'babelify', 'browserify', 'babel-preset-es2015'] :githublink:`%|py|71` """ if module_list is None: module_list = ['babel-core', 'babel-cli', 'babel-preset-env', 'babel-polyfill', 'babelify', 'browserify', 'babel-preset-es2015'] dir_name = dest node_modules = os.path.join(dir_name, "node_modules") should = [os.path.join(node_modules, n) for n in module_list] if any(map(lambda x: not os.path.exists(x), should)): cmds = ['npm install ' + ' '.join(module_list)] errs = [] for cmd in cmds: fLOG("[install_node_js_modules] run ", cmd) err = run_cmd(cmd, wait=True, change_path=dir_name, fLOG=fLOG)[1] errs.append(err) if not os.path.exists(node_modules): raise Exception("Unable to run from '{0}' commands line:\n{1}\n--due to--\n{2}".format( dir_name, "\n".join(cmds), "\n".join(errs)))
[docs]def nodejs_version(): """ Returns :epkg:`node.js` version. :githublink:`%|py|94` """ out, err = run_cmd('node -v', wait=True) if len(err) > 0: raise NodeJsException("Unable to find node\n{0}".format(err)) return out
[docs]def run_js_with_nodejs(script, path_dependencies=None, fLOG=noLOG): """ Runs a :epkg:`javascript` script with :epkg:`node.js`. :param script: script to run :param path_dependencies: where dependencies can be found if needed :param fLOG: logging function :return: output of the script :githublink:`%|py|109` """ script_clean = script.replace("\"", "\\\"").replace("\n", " ") cmd = 'node -e "{0}"'.format(script_clean) out, err = run_cmd(cmd, change_path=path_dependencies, fLOG=fLOG, wait=True) if len(err) > 0: filtered = "\n".join(_ for _ in err.split( '\n') if not _.startswith("[BABEL] Note:")) else: filtered = err if len(filtered) > 0: raise NodeJsException( "Execution of node.js failed.\n--CMD--\n{0}\n--ERR--\n{1}\n--OUT--\n{2}\n--SCRIPT--\n{3}".format(cmd, err, out, script)) return out
_require_cache = {}
[docs]def require(module_name, cache_folder='.', suffix='_pyq', update=False, fLOG=noLOG): """ Modified version of function *require* in ` <>`_. :param module_name: required library name :param cache_folder: location of the files the function creates :param suffix: change the suffix if you use the same folder for multiple files :param update: update the converted script :param fLOG: logging function :return: outcome of the javascript script The function is not fully tested. :githublink:`%|py|141` """ if module_name.endswith('.js'): raise ValueError("module_name must the name without extension .js") global _require_cache if module_name in _require_cache and not update: py_code = _require_cache[module_name] else: from js2py.node_import import ADD_TO_GLOBALS_FUNC, GET_FROM_GLOBALS_FUNC from js2py import translate_js py_name = module_name.replace('-', '_') module_filename = '' % py_name full_name = os.path.join(cache_folder, module_filename) var_name = py_name.rpartition('/')[-1] in_file_name = os.path.join( cache_folder, "require_{0}_in{1}.js".format(module_name, suffix)) out_file_name = os.path.join( cache_folder, "require_{0}_out{1}.js".format(module_name, suffix)) code = ADD_TO_GLOBALS_FUNC code += """ var module_temp_love_python = require('{0}'); addToGlobals('{0}', module_temp_love_python); """.format(module_name) with open(in_file_name, 'w', encoding='utf-8') as f: f.write(code) pkg_name = module_name.partition('/')[0] install_node_js_modules(cache_folder, [pkg_name], fLOG=fLOG) inline_script = "(require('browserify')('%s').bundle(function (err,data)" + \ "{fs.writeFile('%s',require('babel-core').transform(data," + \ "{'presets':require('babel-preset-es2015')}).code,()=>{});}))" inline_script = inline_script % (in_file_name.replace("\\", "\\\\"), out_file_name.replace("\\", "\\\\")) run_js_with_nodejs(inline_script, fLOG=fLOG, path_dependencies=cache_folder) with open(out_file_name, "r", encoding="utf-8") as f: js_code = js_code += GET_FROM_GLOBALS_FUNC js_code += ";var {0} = getFromGlobals('{1}');{0}".format( var_name, module_name) fLOG('[require] translating', out_file_name) py_code = translate_js(js_code) with open(full_name, 'w', encoding="utf-8") as f: f.write(py_code) _require_cache[module_name] = py_code context = {} exec(py_code, context) return context['var'][var_name].to_py()