Add some usecases

nodejs/04_usecases.md

@@ -0,0 +1,69 @@
+!SLIDE bullets incremental
+
+# Use cases
+
+* Realtime applications
+* Web crawlers/scrapers
+* Proxy servers
+* Bridging the client/server gap
+
+!SLIDE
+
+# Code please!
+
+!SLIDE smaller
+
+## webhooks.js
+
+    @@@javascript
+    // Require module from node-core
+    var http = require("http");
+
+    // Attach function to the exports object
+    exports.deliver = function(options, payload, callback) {
+
+      // Create a new http request
+      var req = http.request(options, function(res) {
+        var body = '';
+        res.setEncoding('utf8');
+
+        // Capture the response body
+        res.on('data', function (chunk) {
+          body += chunk;
+        });
+
+        res.on('end', function() {
+          // Return the result to the caller
+          callback(body);
+        });
+      });
+
+      // Send the payload to the endpoint
+      req.write(payload);
+      req.end();
+    };
+
+!SLIDE smaller
+
+## application.js
+
+    @@@javascript
+    // Use a relative require to load the module
+    var webhooks = require("./webhooks");
+
+    // Create a payload and options
+    var payload = {
+      name: "hecticjeff",
+      webscale: true
+    },
+    options = {
+      host: "hecticjeff.net",
+      port: 80,
+      path: "/notify",
+      method: 'POST'
+    };
+
+    // Use the deliver method that we exported
+    webhooks.deliver(options, payload, function(response) {
+      console.log("Webhook responded with %s", response);
+    });