* I'm working on inproving this readme, in the meantime you can contact me if you have any questions!
This simple dependency injector for node is aimed to help solve a very anoying issue when developing in node.js.
Having to require modules by where they are, their physical location relative to where you are now, instead of simply specifying what you need
npm install node-simple-dependency-injector --save
Add the following line at the entry point of your node application
require('node-simple-dependency-injector').config(__dirname);
This will add a global inject
function to your application that we will use below.
inject
will first try to match your some/module/name
to an entry in your config file, if no match was found it will fallback to a normal require
call with the same param.
node-simple-dependency-injector will look for a file called injectorConfig.json
in your __dirname
that will hold your configuration.
Your configuration is a map between the logical module/package names to the physical path in your code base.
Another option is to pass the a json object as the second parameter to config
{
"base": "./server/lib",
"modules": {
"package1": {
"module1": "./some-package/some-module",
"module2": "./some-package/other-module"
}
}
}
With the above configuration you can require your modules like this:
var someModule = inject('package1/module1'); // same as requiring (../)*some-package/some-module
The cool thing is that you can have a different config file when you are running your tests and inject what ever you need
{
"base": "./server/lib",
"modules": {
"package1": {
"module1": "../test/some-package/some-module-mock"
}
}
}
Now when running the same line as before you will get some-module-mock
in all places you injected package1/module1
instead of getting some-module
like we did before.
We have 3 variables here that will construct the path to your module.
root
- The first parameter to theconfig
functionbase
- The value ofbase
in the config jsonpath
- The value ofmodule-logical-name
in your config json
Basically all paths are resolved like this path.join(root, base, path)
.
root
will usually be the__dirname
in your entry point filebase
will be the path from your entry point file to the root of your code base (just to avoid having to write it over and over again for each module)path
should now be the path between wherebase
point and where the actual file is