Examples

julianduque · julianduque · commit 88952c2a4b34 · 2013-03-01T09:13:29.000-05:00
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1 @@
+node_modules
diff --git a/01.js b/01.js
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+//
+// Understanding Async Nature
+//
+function insert(id, callback) {
+  setTimeout(function() {
+    console.log('Insertando ' + id);
+    callback('Exitoso');
+  }, 3000);
+}
+
+console.log('Op1');
+insert(1, function(result) {
+  console.log(result);
+});
+console.log('Op2');
diff --git a/02.js b/02.js
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+//
+// 02 - Pyramid of Doom / Callback Hell/Soup
+//
+console.log('Inicio');
+step1(function(result1) {
+  step2(function(result2) {
+    step3(function(result3) {
+      step4(function(result4) {
+        console.log('Result is: '+ result4);
+      });
+    });
+  });
+});
+console.log('Fin');
+
+function step1(callback) {
+  setTimeout(function () {
+    console.log('Hello step 1');
+    callback(1);
+  }, (Math.random() * 1000));
+}
+
+function step2(callback) {
+  setTimeout(function () {
+    console.log('Hello step 2');
+    callback(2);
+  }, (Math.random() * 1000));
+}
+
+function step3(callback) {
+  setTimeout(function () {
+    console.log('Hello step 3');
+    callback(3);
+  }, (Math.random() *  1000));
+}
+
+function step4(callback) {
+  setTimeout(function () {
+    console.log('Hello step 4');
+    callback(4);
+  }, (Math.random() * 1000));
+}
diff --git a/03.js b/03.js
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+//
+// 03 - Common Problems
+//
+function checkPassword(username, passwordGuess, callback) {
+  var queryStr = 'SELECT * FROM user WHERE username = ?';
+  db.query(selectUser, username, function (err, result) {
+    if (err) throw err;
+      hash(passwordGuess, function(passwordGuessHash) {
+        callback(passwordGuessHash === result.password_hash);
+      });
+  });
+}
+
+function checkPassword(username, passwordGuess, callback) {
+  var passwordHash;
+  var queryStr = 'SELECT * FROM user WHERE username = ?';
+  db.query(selectUser, username, queryCallback);
+
+  function queryCallback(err, result) {
+    if (err) throw err;
+    passwordHash = result.password_hash;
+    hash(passwordGuess, hashCallback);
+  }
+
+  function hashCallback(passwordGuessHash) {
+    callback(passwordHash === passwordGuessHash);
+  }
+}
diff --git a/04.js b/04.js
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+//
+// PubSub
+//
+
+var EE = new require('events').EventEmitter;
+
+var emitter = new EE();
+
+(function() {
+  setTimeout(function() {
+    emitter.emit('action', 'Hello Med.js');
+  }, 5000);
+})(); // Remember IIFE
+
+emitter.on('action', function (params) {
+  console.log(params);
+});
+
+emitter.on('action', function (params) {
+  console.log('I can execute more actions!!');
+});
+
+// jQuery http://jsfiddle.net/jcsdD/
diff --git a/05-server.js b/05-server.js
@@ -0,0 +1,24 @@
+var http = require('http'),
+    fs   = require('fs');
+
+http.createServer(function (req, res) {
+  res.writeHead(200, { 'Content-Type': 'text/html'});
+  switch (req.url) {
+    case '/step1':
+      res.write(JSON.stringify({ step: 1 }));
+      res.end();
+      break;
+    case '/step2':
+      res.write(JSON.stringify({ step: 2 }));
+      res.end();
+      break;
+    default:
+      fs.readFile(__dirname + '/05.html', 'utf-8', function (err, file) {
+        if (err) throw err;
+        res.write(file);
+        res.end();
+      });
+  }
+
+}).listen(8080);
+console.log('Running');
diff --git a/05.html b/05.html
@@ -0,0 +1,32 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset='utf-8' />
+    <title>Demo</title>
+    <script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
+    <script>
+
+      $.ajax({
+        method: 'get',
+        url: 'http://localhost:8080/step1',
+        success: successHandler,
+        error: failHandler
+      });
+
+      $.get('http://localhost:8081/step1').
+        done(successHandler).
+        fail(failHandler);
+
+      function successHandler(response) {
+        console.log(response);
+      }
+
+      function failHandler(response) {
+        console.log(response);
+      }
+    </script>
+  </head>
+  <body>
+    <p>Hello this is demo, see the debug console!</p>
+  </body>
+</html>
diff --git a/05.js b/05.js
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+//
+// Promises
+//
+var Q = require('q'),
+    fs = require('fs');
+
+readFile('05.js').
+  then(fileHandler).
+  fail(failHandler);
+
+
+function readFile(filename) {
+  var fileReading = Q.defer();
+  fs.readFile(filename, 'utf-8',
+    fileReading.makeNodeResolver());
+  return fileReading.promise;
+}
+
+function failHandler (err) {
+  console.error(err);
+}
+
+function fileHandler(file) {
+  console.log(file);
+}
diff --git a/06.js b/06.js
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+//
+// Async.js
+//
+
+function insert(id, callback) {
+  setTimeout(function() {
+    console.log('Inserting ' + id);
+    callback();
+  }, (Math.random() * 1000));
+}
+
+for(var i = 0; i < 10; i++) {
+  insert(i, function() {
+    console.log('Im done with' + i);
+  });
+}
diff --git a/07.js b/07.js
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+var fs = require('fs');
+var concatenation = '';
+fs.readdirSync('.')
+  .filter(function(filename) {
+    // ignore directories
+    return fs.statSync(filename).isFile();
+  }).forEach(function(filename) {
+    // add contents to our output
+    concatenation += fs.readFileSync(filename, 'utf8');
+});
+console.log(concatenation);
diff --git a/07a.js b/07a.js
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+var fs = require('fs');
+var concatenation = '';
+fs.readdir('.', function(err, filenames) {
+  if (err) throw err;
+
+  function readFileAt(i) {
+    var filename = filenames[i];
+    console.log(filename);
+    if (typeof filename !== 'undefined') {
+      fs.stat(filename, function(err, stats) {
+        if (err) throw err;
+        if (!stats.isFile()) return readFileAt(i + 1);
+
+        fs.readFile(filename, 'utf8', function(err, text) {
+          if (err) throw err;
+          concatenation += text;
+
+          if (i + 2 === filenames.length) {
+            // all files read, display the output
+            return console.log(concatenation);
+          }
+
+          readFileAt(i + 1);
+        });
+      });
+    }
+  }
+  readFileAt(0);
+});
diff --git a/07b.js b/07b.js
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+var async = require('async');
+var fs = require('fs');
+
+var concatenation = '';
+var dirContents = fs.readdirSync('.');
+
+async.filter(dirContents, isFilename, function(filenames) {
+  async.eachSeries(filenames, readAndConcat, onComplete);
+});
+
+function isFilename(filename, callback) {
+  fs.stat(filename, function(err, stats) {
+  if (err) throw err;
+    callback(stats.isFile());
+  });
+}
+
+function readAndConcat(filename, callback) {
+  fs.readFile(filename, 'utf8', function(err, fileContents) {
+    if (err) return callback(err);
+    concatenation += fileContents;
+    callback();
+  });
+}
+
+function onComplete(err) {
+  if (err) throw err;
+  console.log(concatenation);
+}
diff --git a/08.js b/08.js
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+//
+// Async.js
+//
+var async = require('async');
+
+function insert(id, callback) {
+  setTimeout(function() {
+    console.log('Inserting ' + id);
+    callback(null, id);
+  }, (Math.random() * 1000));
+}
+
+function filter(data, callback) {
+  callback(data < 3);
+}
+
+var data = [0, 1, 2, 3, 4, 5];
+
+async.filter(data, filter, function(filteredData) {
+  async.eachSeries(filteredData, insert, function(err) {
+    if (err) throw err;
+      console.log('Finished');
+    });
+});
+
+/*async.each(data, insert, function(err) {
+  if (err) throw err;
+  console.log('Finished');
+});*/
+
+
+
+
+
+
+
diff --git a/09.js b/09.js
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+var async = require ('async');
+var start = new Date();
+
+async.parallel([
+  function(callback) { setTimeout(callback, 100); },
+  function(callback) { setTimeout(callback, 300); },
+  function(callback) { setTimeout(callback, 200); }
+], function(err, results) {
+  // show time elapsed since start
+  console.log('Completed in ' + (new Date() - start) + 'ms');
+});
diff --git a/09a.js b/09a.js
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+//
+// 02 - Pyramid of Doom / Callback Hell/Soup
+//
+var async = require('async');
+
+async.parallel([
+  function(callback) {
+    console.log('Inicio');
+    callback(null, 0);
+  },
+  step1,
+  step2,
+  step3,
+  step4
+], function(err, results) {
+  console.log('Result is: ' + results);
+  console.log('Fin');
+});
+
+function step1(callback) {
+  setTimeout(function () {
+    console.log('Hello step 1');
+    callback(null, 'Hola');
+  }, (Math.random() * 1000));
+}
+
+function step2(callback) {
+  setTimeout(function () {
+    console.log('Hello step 2');
+    callback(null, 'Mundo');
+  }, (Math.random() * 1000));
+}
+
+function step3(callback) {
+  setTimeout(function () {
+    console.log('Hello step 3');
+    callback(null, 'Soy Async');
+  }, (Math.random() *  1000));
+}
+
+function step4(callback) {
+  setTimeout(function () {
+    console.log('Hello step 4');
+    callback(null, 4);
+  }, (Math.random() * 1000));
+}
diff --git a/09b.js b/09b.js
