promise chaining achieved

index-chaining.js

@@ -0,0 +1,55 @@
+const fs = require('fs');
+var sleep = require('sleep');
+
+function readFilePromise(fileName) {
+  return new Promise((resolve,reject) => {
+    fs.readFile(fileName, 'utf8', (err,data)=>{
+      if (err) {
+        reject(err);
+      } else {
+        resolve(data);
+      }
+    })
+  })
+}
+
+function matchParentsWithChildrens(parentFileName, childrenFileName) {
+  // read parents
+  let parent_data =[];
+  readFilePromise(parentFileName)
+    .then((data)=>{
+      sleep.sleep(5);
+      parent_data = JSON.parse(data);
+      console.log(`file ${parentFileName} read!`);
+      // read childrens data
+      return readFilePromise(childrenFileName)
+      })
+    .then((data2)=>{
+      sleep.sleep(5);
+      let children_data = JSON.parse(data2);
+      console.log(`file ${childrenFileName} read!`);
+
+      for (let i = 0; i < parent_data.length; i++) {
+        parent_data[i].childrens = [];
+        for (let j = 0; j < children_data.length; j++) {
+          if (parent_data[i].last_name === children_data[j].family) {
+            parent_data[i].childrens.push(children_data[j].full_name);
+          }
+        }
+      }
+      console.log(parent_data);
+
+      })
+    .catch((err)=>{
+      console.log(err);
+      console.log('Terjadi error pada proses pembacaan data');
+      });
+}
+
+
+matchParentsWithChildrens('./parents.json', './childrens.json');
+console.log("Notification : Data sedang diproses !");
+
+// for Release 2
+// matchParentsWithChildrens('./parents.json', './not_a_real_file.json');
+// matchParentsWithChildrens('./not_a_real_file.json', './also_not_a_real_file.json');

index-nested.js

@@ -0,0 +1,55 @@
+const fs = require('fs');
+var sleep = require('sleep');
+
+function readFilePromise(fileName) {
+  return new Promise((resolve,reject) => {
+    fs.readFile(fileName, 'utf8', (err,data)=>{
+      if (err) {
+        reject(err);
+      } else {
+        resolve(data);
+      }
+    })
+  })
+}
+
+function matchParentsWithChildrens(parentFileName, childrenFileName) {
+  // read parents
+  readFilePromise(parentFileName).then((data)=>{
+    sleep.sleep(5);
+    let parent_data = JSON.parse(data);
+    console.log(`file ${parentFileName} read!`);
+    // read childrens data
+    readFilePromise(childrenFileName).then((data2) => {
+      sleep.sleep(5);
+      let children_data = JSON.parse(data2);
+      console.log(`file ${childrenFileName} read!`);
+
+      for (let i = 0; i < parent_data.length; i++) {
+        parent_data[i].childrens = [];
+        for (let j = 0; j < children_data.length; j++) {
+          if (parent_data[i].last_name === children_data[j].family) {
+            parent_data[i].childrens.push(children_data[j].full_name);
+          }
+        }
+      }
+
+      console.log(parent_data);
+
+    }).catch((err)=>{
+      console.log(err);
+      console.log('Terjadi error pada proses pembacaan data');
+    });
+
+  }).catch((err)=>{
+    console.log(err);
+    console.log('Terjadi error pada proses pembacaan data');
+  });
+}
+
+matchParentsWithChildrens('./parents.json', './childrens.json');
+console.log("Notification : Data sedang diproses !");
+
+// for Release 2
+// matchParentsWithChildrens('./parents.json', './not_a_real_file.json');
+// matchParentsWithChildrens('./not_a_real_file.json', './also_not_a_real_file.json');

index-promise-all.js

@@ -0,0 +1,43 @@
+const fs = require('fs');
+var sleep = require('sleep');
+
+function readFilePromise(fileName) {
+  return new Promise((resolve,reject) => {
+    fs.readFile(fileName, 'utf8', (err,data)=>{
+      if (err) {
+        reject(err);
+      } else {
+        resolve(data);
+      }
+    })
+  })
+}
+
+function matchParentsWithChildrens(parentFileName, childrenFileName) {
+  let dataPromises = [];
+  dataPromises.push(readFilePromise(parentFileName))
+  dataPromises.push(readFilePromise(childrenFileName))
+  Promise.all(dataPromises).then((values)=>{
+    let parent_data = JSON.parse(values[0]);
+    let children_data = JSON.parse(values[1]);
+
+    for (let i = 0; i < parent_data.length; i++) {
+      parent_data[i].childrens = [];
+      for (let j = 0; j < children_data.length; j++) {
+        if (parent_data[i].last_name === children_data[j].family) {
+          parent_data[i].childrens.push(children_data[j].full_name);
+        }
+      }
+    }
+    console.log(parent_data);
+
+  }).catch((err)=>{console.log(err)});
+}
+
+
+matchParentsWithChildrens('./parents.json', './childrens.json');
+console.log("Notification : Data sedang diproses !");
+
+// for Release 2
+// matchParentsWithChildrens('./parents.json', './not_a_real_file.json');
+// matchParentsWithChildrens('./not_a_real_file.json', './also_not_a_real_file.json');