From 4d11f34e1deba1470e43271cdfc55bab28c0df8a Mon Sep 17 00:00:00 2001
From: Jannis R <mail@jannisr.de>
Date: Fri, 27 Dec 2019 21:22:01 +0100
Subject: [PATCH] adapt "writing a profile" guide to ctx-based parse fns :memo:

[ci skip]
---
 docs/writing-a-profile.md | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/docs/writing-a-profile.md b/docs/writing-a-profile.md
index cfacca40..fc0098c2 100644
--- a/docs/writing-a-profile.md
+++ b/docs/writing-a-profile.md
@@ -35,25 +35,33 @@ Assuming their HAFAS endpoint returns all line names prefixed with `foo `, we ca
 
 ```js
 // get the default line parser
-const createParseLine = require('hafas-client/parse/line')
+const parseLine = require('hafas-client/parse/line')
 
-const createParseLineWithoutFoo = (profile, opt, data) => {
-	const parseLine = createParseLine(profile, opt, data)
-
-	// wrapper function with additional logic
-	const parseLineWithoutFoo = (l) => {
-		const line = parseLine(l)
-		line.name = line.name.replace(/foo /g, '')
-		return line
-	}
-	return parseLineWithoutFoo
+// wrapper function with additional logic
+const parseLineWithoutFoo = (ctx, rawLine) => {
+	const line = parseLine(ctx, rawLine)
+	line.name = line.name.replace(/foo /g, '')
+	return line
 }
 
-profile.parseLine = createParseLineWithoutFoo
+myProfile.parseLine = parseLineWithoutFoo
 ```
 
 If you pass this profile into `hafas-client`, the `parseLine` method will override [the default one](../parse/line.js).
 
+You can also use the `parseHook` helper to reduce boilerplate:
+
+```js
+const {parseHook} = require('hafas-client/lib/profile-hooks')
+
+const removeFoo = (ctx, rawLine) => ({
+	...ctx.parsed,
+	name: line.name.replace(/foo /g, '')
+})
+
+myProfile.parseLine = parseHook(parseLine, removeFoo)
+```
+
 ## 1. Setup
 
 *Note*: There are many ways to find the required values. This way is rather easy and has worked for most of the apps that we've looked at so far.