Different settings for debug/local ("grunt serve") vs. dist/build ("grunt")? - javascript

I want to define some application settings, but I want to provide different values depending on whether I'm running in 'debug' mode (e.g. grunt serve), or whether the final compiled app is running (e.g. the output of grunt). That is, something like:
angular.module('myApp').factory('AppSettings', function() {
if (DebugMode()) { // ??
return { apiPort: 12345 };
} else {
return { apiPort: 8008 };
}
});
How can I accomplish this?

The way I handle it in my apps:
move all your config data for one environment to a file: config.js, config.json,... whatever your app finds easy to read.
now modify your config file to turn it into a template using grunt config values, and generate the file with grunt-template as part of your build - for example: app.constant('myAppConfig', {bananaHammocks: <%= banana.hammocks %>});
finally, add grunt-stage to switch grunt config values depending on environment: create your different config/secret/(env).json files, update your template (app.constant('myAppConfig', {bananaHammocks: <%= stg.banana.hammocks %>});), and then grunt stage:local:build or grunt stage:prod:build
I find this the good balance between complexity and features (separation between environments, runtime code not concerned with building options,...)

Related

Application modularity with Vue.js and local NPM packages

I'm trying to build a modular application in Vue via the vue-cli-service. The main app and the modules are separated projects living in different folders, the structure is something like this:
-- app/package.json
/src/**
-- module1/package.json
/src**
-- module2/package.json
/src**
The idea is to have the Vue app completely agnostic about the application modules that can be there at runtime, the modules themself are compiled with vue-cli-service build --target lib in a local moduleX/dist folder, pointed with the package.json "main" and "files" nodes.
My first idea (now just for development speed purposes) was to add the modules as local NPM packages to the app, building them with a watcher and serving the app with a watcher itself, so that any change to the depending modules would (I think) be distributed automatically to the main app.
So the package.json of the app contains dependencies like:
...
"module1": "file:../module1",
"module2": "file:../module2",
...
This dependencies are mean to be removed at any time, or in general be composed as we need, the app sould just be recompiled and everything should work.
I'm trying to understand now how to dynamically load and activate the modules in the application, as I cannot use the dynamic import like this:
import(/* webpackMode: "eager" */ `module1`).then(src => {
src.default.boot();
resolve();
});
Because basically I don't know the 'module1', 'module2', etc...
In an OOP world I would just use dependency injection retrieving classes implementing a specific interface, but in JS/TS I'm not sure it is viable.
There's a way to accomplish this?
Juggling with package.json doesn't sound like a good idea to me - doesn't scale. What I would do:
Keep all available "modules" in package.json
Create separate js file (or own prop inside package.json) with all available configurations (for different clients for example)
module.exports = {
'default': ['module1', 'module2', 'module3'],
'clientA': ['module1', 'module2', 'module4'],
'clientB': ['module2', 'module3', 'module4']
}
tap into VueCLI build process - best example I found is here and create js file which will run before each build (or "serve") and using simple template (for example lodash) generate new js file which will boot configured modules based on the value of some ENV variable. See following (pseudo)code (remember this runs inside node during build):
const fs = require('fs')
const _ = require('lodash')
const modulesConfig = require(`your module config js`)
const configurationName = process.env.MY_APP_CONFIGURATION ?? 'default'
const modules = modulesConfig[configurationName]
const template = fs.loadFileSync('name of template file')
const templateCompiled = _.template(template)
const generatedJS = templateCompiled({ `modules`: modules })
fs.writeFileSync('bootModules.js', generatedJS)
Write your template for bootModules.js. Simplest would be:
<% _.forEach(modules , function(module) { %>import '<%= module %>' as <%= module %><% }); %>;
import bootModules.js into your app
Use MY_APP_CONFIGURATION ENV variable to switch desired module configuration - works not just during development but you can also setup different CI processes targeting same repo with just different MY_APP_CONFIGURATION values
This way you have all configurations at one place, you don't need to change package.json before every build, you have simple mechanism to switch between different module configurations and every build (bundle) contains only the modules needed....
In an OOP world I would just use dependency injection retrieving classes implementing a specific interface, but in JS/TS I'm not sure it is viable.
Why not?
More than this, with JS/TS you are not restricted to use classes implementing a specific interface: you just need to define the interface (i.e. the module.exports) of your modules and respecting it in the libraries entries (vue build lib).
EDIT: reading comments probably I understood the request.
Each module should respect following interface (in the file which is the entry of the vue library)
export function isMyAppModule() {
return true;
}
export function myAppInit() {
return { /* what you need to export */ };
}
Than in your app:
require("./package.json").dependencies.forEach(name => {
const module = require(name);
if(! module.isMyAppModule || module.isMyAppModule() !== true) return;
const { /* the refs you need */ } = module.myAppInit();
// use your refs as you need
});

Separating/combining gulp task sources using yargs and gulp-if

Lets say I want to include all js files in a source folder concatenated in a specific order (using gulp-concat). However, I want to only include certain files if there is a production flag.
For example, in production I need these files:
modals.js
utilities.js
analytics.js
signup.js
cookies.js
However, for local and staging, I don't want these two:
analytics.js
cookies.js
Is it possible using yargs and perhaps gulp-if to specify this? I know that I could have two lists of sources, for instance:
if (argv.production) {
return gulp.src([
'modals.js',
'utilities.js',
'analytics.js',
'signup.js',
'cookies.js'
])
} else if (argv.staging) {
return gulp.src([
'modals.js',
'utilities.js',
'signup.js',
])
}
However, this would mean I'm not adhering to DRY principles, and just feels silly and prone to error. Can I somehow stitch these together as a single source that only includes things like analytics and cookies if the task has a production flag?
In an ideal world, I could inject gulp if statements inside the gulp.src array that would only include the production-only files if the correct flag were passed.
Some out-loud thinking:
- Should I just create two files here? One a base that includes everything necessary across environments, and then a production specific one, then combine those? Seems unnecessarily complex, but could solve the problem.
If your goal is to be a bit more DRY, you can give this a shot, since your set of staging files is a subset of the production files:
var base_list = ['modals.js', 'utilities.js', 'signup.js'];
if (argv.staging) {
return gulp.src(base_list);
} else if (argv.production) {
var prod_list = base_list.concat(['analytics.js', 'cookies.js']);
return gulp.src(prod_list);
}
Or more simplified (as long as only production needs the other files, and all other environments get the subset):
var file_list = ['modals.js', 'utilities.js', 'signup.js'];
if (argv.production) {
file_list = file_list.concat(['analytics.js', 'cookies.js']);
}
return gulp.src(file_list);
There might be some other gulp-specific best practices or tools that could come into play here, but some simple JavaScript might do the trick.

Webpack replace module runtime

I have a rather complex scenario.
We are building a desktop application with React which is wrapped with Electron, Webpack takes care of the Babel transpilation and chunking.
The application receives configuration data from a cms.
Part of the configuration may be a javascript class that needs to override one that resides in the application. The JS code as specified in the CMS will be vanilla Javascript code (ES6/7/8 same as what we use for the application)
I see 2 problems here:
How to transpile just this one class and
How to replace it runtime in the application
Is this even possible?
Regards
If with "The application receives configuration data from a cms." you mean runtime data, then, because Webpack acts at compile time, it cannot help you to transpile/replace your code (Runtime vs Compile time).
if your data from a CMS can be fetched at compile time, then, notice that you can return a promise from webpack.config.js.
module.exports = function webpackConfig(env) {
const configs = {
context: __dirname,
plugins: []
// etc...
};
return CMS
.fetchConfig()
.then(cmsConfigs => {
const vars = {
replaceClass: JSON.stringify(cmsConfigs.classINeed.toString())
};
configs.plugins.push(new webpack.DefinePlugin(vars));
return configs;
})
;
}

browserify - exclude code blocks?

I'm building an app with shared React components in the browser and server-side Node.
Right now, I'm using Marty.js to do this:
function getUser() {
if (Marty.isBrowser) {
/* Get user using some client method */
} else {
/* otherwise, use some secret server code */
}
}
I'm bundling those functions up via Browserify, so they can run on the client as well as the server.
What I'd like to do is remove the else block from the bundle entirely, so I'm not leaking sensitive server-side code.
Is there a way to exclude blocks of code from the bundle?
I would create separate modules, one for the browser and one for the server. Then in your package.json, you tell browserify to use the browser module:
"browser": {
"./path/to/node-module.js": "./path/to/browser-module.js"
}
Now, whereever you call require('path/to/node-module'), browserify will load the other module instead.
More information from the docs:
browser field
There is a special "browser" field you can set in your package.json on a per-module basis to override file resolution for browser-specific versions of files.
For example, if you want to have a browser-specific module entry point for your "main" field you can just set the "browser" field to a string:
"browser": "./browser.js"
or you can have overrides on a per-file basis:
"browser": {
"fs": "level-fs",
"./lib/ops.js": "./browser/opts.js"
}
Note that the browser field only applies to files in the local module, and like transforms, it doesn't apply into node_modules directories.
While I'm not sure if it possible with Browserify, you can do it with Webpack using its DefinePlugin
From the docs (little modified):
Example:
new webpack.DefinePlugin({
DEBUG: false,
PRODUCTION: true,
...
})
...
Example:
if(DEBUG)
console.log('Debug info')
if(PRODUCTION)
console.log('Production log')
After passing through webpack with no minification results in:
if(false)
console.log('Debug info')
if(true)
console.log('Production log')
and then after a minification pass results in:
console.log('Production log')
You can use an environment variable, envify and uglify to do this.
if ('browser' === process.env.ENVIRONMENT) {
...
}
else {
...
}
Set process.env.ENVIRONMENT = 'browser' when doing your browser build, use the envify transform to substitute references to process.env with their current values and uglify will then perform dead code elimination to remove the branches which will never be hit.
Be more explicit about your intent, and put your code in their own files:
function getUser(options, callback) {
var fn;
if (Marty.isBrowser) {
fn = require("./lib/users/get.browser");
} else {
fn = require("./lib/users/get.server");
}
fn(options, callback);
}
and then as a browserify option you can say "replace require("./lib/users/get.server") with this variable instead, when you see it: ..." so that you don't build in that server file when you build for the browser.
However, if getUser can do different things based on where it's running, it feels far more likely that you're doing something wrong here: maybe that getUser should be a REST call to your server from the browser instead, but without more information, that's always hard to determine.
What about putting the code in a module for example UserServer and then exclude that module when you are compiling for the client? Your code becomes:
function getUser() {
if (Marty.isBrowser) {
/* Get user using some client method */
} else {
require('UserServer').getUser();
}
}
Browserify provides the following option to exclude files from the bundle:
--exclude, -u Omit a file from the output bundle. Files can be globs.

Minify Scripts/CSS in production mode with node.js

I have a web app that runs in node. All the (client) Javascript/CSS files are not minified at the moment to make it easier to debug.
When I am going into production, I would like to minify these scripts. It would be nice to have something like:
node app.js -production
How do I serve the minified version of my scripts without changing the script tags in my html files? There should be something like: if I am in production, use these 2 minified(combined) scripts, else use all my unminified scripts..
Is this possible? Maybe I am thinking too complicated?
You might be interested in Piler. It's a Node.js module that delivers all the JavaScript (and CSS) files you specify as usual when in debug mode, but concatenated and minified when in production mode.
As a special feature, you can force CSS updates via Socket.io in real-time to appear in your browser (called "CSS Live Updated" in Piler), which is quite awesome :-).
The trick is that inside your template you only have placeholders for the script and link elements, and Piler renders these elements at runtime - as single elements in debug mode, and as a dynamically generated single element in production mode.
This way you can forget about creating concatenated and minified versions of your assets manually or using a build tool, it's just there at runtime, but you always have the separated, full versions when developing and debugging.
you could use 2 separate locations for your static files
Here's some express code:
if (process.env.MODE === "production") {
app.use(express['static'](__dirname + '/min'));
} else {
app.use(express['static'](__dirname + '/normal'));
}
and start node with
MODE=production node app.js
Furthermore, if you don't want to duplicate all your files, you could take advantage of the fact that express static router stops at the first file, and do something like this instead:
if (process.env.MODE === "production") {
app.use(express['static'](__dirname + '/min')); // if minized version exists, serves it
}
app.use(express['static'](__dirname + '/normal')); // fallback to regular files
Using the same name for minimized or not is going to cause problem with browser caching, though.
I want to share my final solution with you guys.
I use JSHTML for Express (enter link description here)
In my main node file I use a special route:
app.get('/**:type(html)', function (req, res, next) {
var renderingUrl = req.url.substring(1, req.url.lastIndexOf("."));
//TODO: Find a better solution
try{
var assetUrl = req.url.substring(req.url.lastIndexOf("/") + 1, req.url.lastIndexOf("."));
var assets = config.getResourceBundle(assetUrl);
assets.production = config.getEnviroment() === "production";
res.locals(assets);
res.render(renderingUrl);
}catch(e){
res.redirect("/");
}
});
As you can see, I get my assets from config.getResourceBundle. This is a simply function:
exports.getResourceBundle = function(identifier){
switch(enviroment){
case "development":
return devConfig.getResourceBundle(identifier);
case "production":
return prodConfig.getResourceBundle(identifier);
default:
return devConfig.getResourceBundle(identifier);
}
}
And finally an example for an asset file collection is here:
exports.getResourceBundle = function (identifier) {
return resourceBundle[identifier];
};
resourceBundle = {
index:{
cssFiles:[
"resources/dev/css/login.css",
"resources/dev/css/logonDlg.css",
"resources/dev/css/footer.css"
],
jsFiles:[
"resources/dev/js/lib/jquery/jquery.183.js",
"resources/dev/js/utilities.js",
"resources/dev/js/lib/crypto.3.1.2.js"
]
},
register:{
cssFiles:[
"resources/dev/css/login.css",
"resources/dev/css/modalDialog.css",
"resources/dev/css/footer.css"
],
jsFiles:[
"resources/dev/js/lib/jquery/jquery.183.js",
"resources/dev/js/utilities.js",
"resources/dev/js/lib/crypto.3.1.2.js",
"resources/dev/js/lib/jquery.simplemodal.js",
"resources/dev/js/xfiles.register.js"
]
}
(...)
I have 2 folders. dev / prod. grunt will copy the minified files into prod/.. and deletes the files from dev/...
And if the NODE_ENV variable is set to production, I will ship the minified versions of my scripts/css.
I think this is the most elegant solution at the moment.
There are build tool plugins for you, may help you gracefully solve this problem:
For Gulp:
https://www.npmjs.org/package/gulp-useref/
For Grunt:
https://github.com/pajtai/grunt-useref
Another Node.js module which could be relevant is connect-cachify.
It doesn't seem to do the actual minification for you, but it does let you serve the minified version in production, or all the original scripts in development, without changing the templates (thanks to cachify_js and cachify_css).
Seems it's not as feature-rich as Piler, but probably a bit simpler, and should meet all the requirements mentioned in the question.

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