Initial implementation

Author: joeltg

index.js

@@ -0,0 +1,55 @@
+const CID = require("cids")
+
+function parseJSON(bytes, callback) {
+	const string = bytes.toString("utf8")
+	let res = null,
+		error = null
+	try {
+		res = { document: JSON.parse(string) }
+	} catch (e) {
+		error = e
+	} finally {
+		callback(error, res)
+	}
+}
+
+const ipldLoaders = {
+	"dag-pb"(value, callback) {
+		parseJSON(value.data, callback)
+	},
+	"dag-cbor"(value, callback) {
+		callback(null, { document: value })
+	},
+}
+
+const documentLoaders = {
+	"dweb:/ipfs/"(ipfs, path, callback) {
+		ipfs.files.cat(path, (err, bytes) => {
+			if (err) callback(err)
+			else parseJSON(bytes, callback)
+		})
+	},
+	"dweb:/ipld/"(ipfs, path, callback) {
+		let cid
+		try {
+			cid = new CID(path)
+		} catch (e) {
+			callback(e)
+		}
+		if (ipldLoaders.hasOwnProperty(cid.codec))
+			ipfs.dag.get(path, (err, { value }) => {
+				if (err) callback(err)
+				else ipldLoaders[cid.codec](value, callback)
+			})
+		else callback(new Error("Unrecognized IPLD format"))
+	},
+}
+
+const keys = Object.keys(documentLoaders)
+const getDocumentLoader = ipfs => (url, callback) => {
+	const key = keys.find(key => url.indexOf(key) === 0)
+	if (key) documentLoaders[key](ipfs, url.slice(key.length), callback)
+	else callback(new Error("Could not load document", url))
+}
+
+module.exports = getDocumentLoader

package-lock.json

@@ -0,0 +1,28 @@
+{
+  "name": "jsonld-dweb-loader",
+  "version": "1.0.0",
+  "description": "JSON-LD document loader for IPFS and IPLD URIs",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/joeltg/jsonld-dweb-loader.git"
+  },
+  "keywords": [
+    "ipfs",
+    "ipld",
+    "dweb",
+    "jsonld"
+  ],
+  "author": "Joel Gustafson",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/joeltg/jsonld-dweb-loader/issues"
+  },
+  "homepage": "https://github.com/joeltg/jsonld-dweb-loader#readme",
+  "dependencies": {
+    "cids": "^0.5.5"
+  }
+}