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6119f07007
* Fixes some route creation and updating bugs. * Updated README * Added more info the quickstart * Updated based on PR comments. * Fixed based on comments. * Updated per comments.
109 lines
3.6 KiB
Markdown
109 lines
3.6 KiB
Markdown
# Extending IronFunctions
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IronFunctions is extensible so you can add custom functionality and extend the project without needing to modify the core.
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There are 4 different ways to extend the functionality of IronFunctions.
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1. Listeners - listen to API events such as a route getting updated and react accordingly.
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1. Middleware - a chain of middleware is executed before an API handler is called.
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1. Add API Endpoints - extend the default IronFunctions API.
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1. Special Handlers - TODO: DO WE NEED THIS ANYMORE??
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## Listeners
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Listeners are the main way to extend IronFunctions.
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You can easily use listeners basically creating a struct with [valid methods](#Listener Requirements) and adding it to the `IronFunctions API`.
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Example:
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```
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package main
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import (
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"context"
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"github.com/iron-io/functions/api/server"
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"github.com/iron-io/functions/api/models"
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)
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type myCustomListener struct{}
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func (c *myCustomListener) BeforeAppCreate(ctx context.Context, app *models.App) error { return nil }
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func (c *myCustomListener) AfterAppCreate(ctx context.Context, app *models.App) error { return nil }
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func (c *myCustomListener) BeforeAppUpdate(ctx context.Context, app *models.App) error { return nil }
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func (c *myCustomListener) AfterAppUpdate(ctx context.Context, app *models.App) error { return nil }
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func (c *myCustomListener) BeforeAppDelete(ctx context.Context, app *models.App) error { return nil }
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func (c *myCustomListener) BeforeAppDelete(ctx context.Context, app *models.App) error { return nil }
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function main () {
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srv := server.New(/* Here all required parameters to initialize the server */)
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srv.AddAppListener(myCustomListener)
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srv.Run()
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}
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```
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### Creating a Listener
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These are all available listeners:
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#### App Listeners
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See the godoc for AppListener [in this file](/iron-io/functions/blob/master/api/server/apps_listeners.go)
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#### Runner Listeners
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See the godoc for RunnerListner [in this file](/iron-io/functions/blob/master/api/server/runner_listeners.go).
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## Adding API Endpoints
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You can add API endpoints by using the `AddEndpoint` and `AddEndpointFunc` methods to the IronFunctions server.
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See examples of this in [/examples/extensions/main.go](/examples/extensions/main.go).
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## Middleware
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Middleware enables you to add functionality to every API request. For every request, the chain of Middleware will be called
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in order allowing you to modify or reject requests, as well as write output and cancel the chain.
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NOTES:
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* middleware is responsible for writing output if it's going to cancel the chain.
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* cancel the chain by returning an error from your Middleware's Serve method.
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See examples of this in [/examples/Middleware/main.go](/examples/middleware/main.go).
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## Special Handlers
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To understand how **Special Handlers** works you need to understand what are **Special Routes**.
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**Special Routes** are routes that doesn't match any other API route.
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With **Special Handlers** you can change the behavior of special routes in order to define which function is going to be executed.
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For example, let's use special handlers to define `mydomain` as the `appname` for any request for `mydomain.com`.
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```
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type SpecialHandler struct{}
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func (h *SpecialHandler) Handle(c server.HandlerContext) error {
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host := c.Request().Host
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if host == "mydomain.com" {
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c.Set("app", "mydomain")
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}
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}
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func main () {
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sh := &SpecialHandler{}
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srv := server.New(/* Here all required parameters to initialize the server */)
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srv.AddSpecialHandler(sh)
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srv.Run()
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}
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```
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With the code above, a request to `http://mydomain.com/hello` will trigger the function `/mydomain/hello` |