Old examples of old spevs

Signed-off-by: Fabio José <fabiojose@gmail.com>

OLDOCS.md

@@ -0,0 +1,177 @@
+# Docs for old spec versions
+
+Here are living the examples of old specs implementations.
+
+## How to use
+
+The `Cloudevent` constructor arguments.
+
+```js
+/*
+ * spec  : if is null, set the spec 0.1 impl
+ * format: if is null, set the JSON Format 0.1 impl
+ */
+Cloudevent(spec, format);
+
+```
+
+### Usage
+
+```js
+var Cloudevent = require("cloudevents-sdk");
+
+var Spec02 = require("cloudevents-sdk/v02");
+
+/*
+ * Constructs a default instance with:
+ *   - Spec 0.1
+ *   - JSON Format 0.1
+ */
+var cloudevent01 = new Cloudevent();
+
+/*
+ * Implemented using Builder Design Pattern
+ */
+cloudevent01
+  .type("com.github.pull.create")
+  .source("urn:event:from:myapi/resourse/123");
+
+/*
+ * Backward compatibility to spec 0.1 by injecting methods from spec
+ * implementation to Cloudevent
+ */
+cloudevent01
+  .eventTypeVersion("1.0");
+
+/*
+ * Constructs an instance with:
+ *   - Spec 0.2
+ *   - JSON Format 0.1
+ */
+var cloudevent02 = new Cloudevent(Cloudevent.specs["0.2"]);
+
+/*
+ * Different specs, but the same API.
+ */
+cloudevent02
+  .type("com.github.pull.create")
+  .source("urn:event:from:myapi/resourse/123");
+
+```
+
+#### Formatting
+
+```js
+var Cloudevent = require("cloudevents-sdk");
+
+/*
+ * Creates an instance with default spec and format
+ */
+var cloudevent =
+  new Cloudevent()
+        .type("com.github.pull.create")
+        .source("urn:event:from:myapi/resourse/123");
+
+/*
+ * Format the payload and return it
+ */
+var formatted = cloudevent.format();
+```
+
+#### Emitting
+
+```js
+var Cloudevent = require("cloudevents-sdk");
+
+// The event
+var cloudevent =
+  new Cloudevent()
+    .type("com.github.pull.create")
+    .source("urn:event:from:myapi/resourse/123");
+
+// The binding configuration using POST
+var config = {
+  method: "POST",
+  url   : "https://myserver.com"
+};
+
+/*
+ * To use HTTP Binary:
+ *   Cloudevent.bindings["http-binary0.2"](config);
+ */
+
+// The binding instance
+var binding = new Cloudevent.bindings["http-structured0.1"](config);
+
+// Emit the event using Promise
+binding.emit(cloudevent)
+  .then(response => {
+    // Treat the response
+    console.log(response.data);
+
+  }).catch(err => {
+    // Deal with errors
+    console.error(err);
+  });
+```
+
+#### Receiving Events
+
+You can choose any framework for port binding. But, use the Unmarshaller
+to process the HTTP Payload and HTTP Headers, extracting the CloudEvents.
+
+The Unmarshaller will parse the HTTP Request and decides if it is a binary
+or a structured version of transport binding.
+
+:smiley: **Checkout the full working example: [here](./examples/express-ex).**
+
+```js
+// some parts were removed //
+
+const v02 = require("cloudevents-sdk/v02");
+const unmarshaller = new v02.HTTPUnmarshaller();
+
+// some parts were removed //
+
+app.post('/', function (req, res) {
+  unmarshaller.unmarshall(req.body, req.headers)
+    .then(cloudevent => {
+
+      // TODO use the cloudevent
+
+      res.status(201)
+            .send("Event Accepted");
+  })
+  .catch(err => {
+    console.error(err);
+    res.status(415)
+          .header("Content-Type", "application/json")
+          .send(JSON.stringify(err));
+  });
+});
+```
+
+## The API
+
+### `Unmarshaller` classes
+
+The Unmarshaller classes uses the receiver API, abstracting the formats:
+
+- structured
+- binary
+
+Choosing the right implementation based on the `headers` map.
+
+```js
+/*
+ * Constructor without arguments
+ */
+Unmarshaller()
+
+/*
+ * The method to unmarshall the payload.
+ * @arg payload could be a string or a object
+ * @arg headers a map of headers
+ */
+Promise Unmarshaller.unmarshall(payload, headers)
+```