Backup, Remove and Restore your Contacts

backup.js

function backupAllTheContacts() {
    navigator.contacts.find(["*"], function(contacts) {
        console.log("contacts.length = " + contacts.length);
        window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function(fileSystem) {
            fileSystem.root.getFile("contacts.bak", {create: true, exclusive: false}, function(fileEntry) {
                fileEntry.createWriter(function(writer) {
                    writer.onwriteend = function() {
                        console.log("backup complete");
                    };
                    writer.write(JSON.stringify(contacts));
                }, onError);
            }, onError);
        }, onError);
    }, onError, {"multiple": true});    
}

contacts.json

[
  {
    "id": "4",
    "rawId": "4",
    "displayName": "123 456",
    "name": {
      "familyName": "456",
      "formatted": "123 456",
      "givenName": "123"
    },
    "nickname": null,
    "phoneNumbers": null,
    "emails": null,
    "addresses": null,
    "ims": [
      {
        "type": -1,
        "value": ".adgjm",
        "id": "8",
        "pref": false
      }
    ],
    "organizations": null,
    "birthday": null,
    "note": null,
    "photos": null,
    "categories": null,
    "urls": null
  },
  {
    "id": "5",
    "rawId": "5",
    "displayName": "Dooney Evans",
    "name": {
      "middleName": "",
      "familyName": "Evans",
      "formatted": "Dooney  Evans",
      "givenName": "Dooney"
    },
    "nickname": null,
    "phoneNumbers": [
      {
        "type": "work",
        "value": "512-555-1234",
        "id": "11",
        "pref": false
      }
    ],
    "emails": null,
    "addresses": null,
    "ims": null,
    "organizations": null,
    "birthday": null,
    "note": null,
    "photos": null,
    "categories": null,
    "urls": null
  },
  {
    "id": "18",
    "rawId": "18",
    "displayName": "John Doe",
    "name": {
      "familyName": "Doe",
      "formatted": "John Doe",
      "givenName": "John"
    },
    "nickname": null,
    "phoneNumbers": null,
    "emails": null,
    "addresses": null,
    "ims": null,
    "organizations": null,
    "birthday": null,
    "note": null,
    "photos": null,
    "categories": null,
    "urls": null
  },
  {
    "id": "19",
    "rawId": "19",
    "displayName": "Rob Doe",
    "name": {
      "familyName": "Doe",
      "formatted": "Rob Doe",
      "givenName": "Rob"
    },
    "nickname": null,
    "phoneNumbers": null,
    "emails": null,
    "addresses": null,
    "ims": null,
    "organizations": null,
    "birthday": null,
    "note": null,
    "photos": null,
    "categories": null,
    "urls": null
  }
]

delete.js

function deleteAllTheContacts() {
    var deleteContact = function(contacts) {
        console.log("length = " + contacts.length);
        // No contacts left, stop saving
        if (contacts.length == 0) {
            console.log("All contacts removed");
            return;
        }
    
        var contact = contacts.pop();
        contact.remove(function() {
            deleteContact(contacts);
        }, null);
    };
    
    navigator.contacts.find(["*"], deleteContact, onError, {"multiple": true});
}

restore.js

function restoreContacts() {
    window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function(fileSystem) {
        fileSystem.root.getFile("contacts.bak", {create: false, exclusive: false}, function(fileEntry) {
            fileEntry.file(function(fp) {
                var reader = new FileReader();
                    reader.onloadend = function (evt) {
                        console.log("read success");
                        saveAllTheContacts(JSON.parse(evt.target.result));
                    };
                    reader.readAsText(fp);
                }, onError);
        }, onError);
    }, onError);
}

function saveAllTheContacts(contacts) {
  var saveContacts = function() {
    // No contacts left, stop saving
    if (contacts.length == 0) {
        console.log("contacts restored");
        return;
    }
    
    var contactData = contacts.pop();
    contactData.id = null;
    contactData.rawId = null;
    var contact = navigator.contacts.create(contactData);
    contact.save(function() {
        saveContacts();
    }, null);
  };
 
  saveContacts();
}