lr-main reference
Changelog in v2.0.1
- Simplified code and usage, reduced package by almost 90% to 1.3KB
- Parallel processing, speeding up and non blocking
- Removed the complete next callback, working with returns
- Simpler interface, no more relay, you have control over the complete road at runtime
- Dynamic assignment of callbacks (previously middleware) is now possible
- Extensions are not so deeply nested anymore
- Removed the updateable extensions, now just pass in the road object to an extension
The lr-main package is the only mandatory package for Lagoon road. This package connects everything together, regardless of environment.
| Information | - |
|---|---|
| Code coverage |  |
| Repo link | lr-main |
| Dependencies | check-types |
| Size (Gzip) | 1.3KB |
| Version | 2.0.0 |
| License | MIT |
| Usage | guide |
core(environmentId)
const road = require('lr-main')('webserver');
environmentId:string
The primary environment id for the road, this is the executing environment that will be used when an update event is fired.
road.parser(parser)
const parser = require('lr-url-parser')();
road.parser(parser);
parser:object
The parser that you want to use to parse an incoming matchValue. It expects two functions in the object, add and parse. Read more about parsers in the guide
road.extension(extensionId, extension)
road.extension('router', router, true);
extensionId:string
A unique id to identify the extension.
extension:*
The actual extension, this can be any type of code that you want to use
Extensions are available on the road object in the callback
module.exports = road => { console.log(road.extensionName); }
road.callback(id, callbackFunction)
road.callback('debug', road => { console.log(road) });
id:string
Unique id to identify the current callback function
callbackFunction:function The actual function that you want to call, it will have the road as parameter and some optional paramaters that might have been given by the update event.
module.exports = road => {
// body
return { key : value } // Return an object, this will be added to the road object
}
road.where(environmentId, [...environmentId])
road.where('webserver', 'client');
environmentId
The where method expects at least one argument, which should be a string. This is an environment id to which all the following callback will be assigned. If you want to assign callback to multiple environments you can just specify several ids like in the example above.
road.run(matchValue, callbackId, [matchValue])
road
.run('*', 'log'); // All matches
.run('/some-url', 'log'); // This specific match
.run('-/some-url', 'log'); // Everything except this match
matchValue:string
A match value in most webapps can be thought of as an url path, but it is not limited to paths only. Frankly it can be any string you can think of, even a JSON string to match on JSON content. Or in an even more exotic example you can match Raspberry Pie sensor outputs via an extension to string values and let that trigger callbacks. You can use the * as a wildcard to match on all match values that might come in or - if you want to run it on all the paths except the given one.
callbackId:string
Identifier you added by using the callback method. It needs to be a string and should match to a callback function, otherwise it will throw an error.
[updateType:string]
The update type is an extra layer for matching callback, if we use a http protocol to update the road, this will be the method for the request. By default it wil be GET because it is the most common, but it can be overwritten to be something else. Again you are not limited to http methods, it fully depends on what an extension sends out via an update event.
road.fail(callbackId)
road.fail('log')
Whenever a callback throws an error, it will be redirected to error callback. You can use it to render alternative content or log the errors. The road object will have a new property error with the error. The fail method will also be called when no callbacks could be found for the current matchValue.
callbackId:string
Identifier you added by using the callback method. It needs to be a string and should match to a callback function, otherwise it will throw.
road.update(options:object, [...parameters])
road.update({ matchValue : '/somepath', updateType : 'post' }, parameterOne, parameterTwo);
Manually trigger an update event to the road by calling the update method.
options.matchValue:string
A match value in most webapps can be thought of as an url path, but it is not limited to paths only. Frankly it can be any string you can think of, even a JSON string to match on JSON content. Or in an even more exotic example you can match Raspberry pie sensor outputs via an extension to string values and let that trigger callback. You can use the * as a wildcard to match on all match values that might come in.
options.updateType:string
The update type is an extra layer for matching callback, if we use a http protocol to update the road, this will be the method for the request. By default it wil be GET because it is the most common, but it can be overwritten to be something else. Again you are not limited to http methods, it fully depends on what an extension sends out via an update event.
parameters:*
Each update can be have custom parameters that will be available as callback arguments. This could be for example the request and response object on a router update.
Road object
The road object is passed from callback function to callback function.
road.parameters:object
If you are using a parser that supplies you with parameters like lr-url-parser, you can access them via road.parameters.
road.update(options:object):function
See update method for usage.
road.callbacks:object
All the callbacks that are assigned.
other
There are more properties on the road object, do a dump to see an overview of all properties and methods.