Best Method to persist data locally in Windows 8 app - javascript

I'm creating a Windows 8 App (using HTML 5 and JavaScript) for someone and they've changed up the requirements on me as far as data storage and I could use some guidance. What I need is a data source that will persist only for the local user and not be online in a database or in the cloud. The users will be assigned a tablet with the app installed and they will enter data via forms to customize their local copy.
Here's my requirements:
-Data MUST persist through the lifetime that the app is installed on the device.
-I need to be able to query the data to some degree. I've basically got about 15-20 forms that will accept input data and then a main form that will feed off those 15-20 "sub" forms to populate drop-down and selection options.
-Size should not be an issue, it's all text data and not much of it will be entered. Can't see this going more than a couple hundred MBs over the lifetime of the app.
I've looked into XML, indexedDB (sounds good on the outside, but haven't found any kind of guarantee this will persist), and Application Data (local) which seems extremely limited in my reading capabilities.
What do you think my best bet is? Any advice would be greatly appreciated.
Thanks.

This should help
(function () {
"use strict";
var page = WinJS.UI.Pages.define("/html/index.html", {
ready: function (element, options) {
//do your things
}
});
var roamingFolder = Windows.Storage.ApplicationData.current.roamingFolder;
var afile = "FileToStoreStuff.txt";
function makefile() {
roamingFolder.createFileAsync(afile, Windows.Storage.CreationCollisionOption.replaceExisting)
.then(function (file) {
return Windows.Storage.FileIO.writeTextAsync(file);
})
}
function fileRead() {
roamingFolder.getFileAsync(filename)
.then(function (file) {
return Windows.Storage.FileIO.readTextAsync(file);
}).done(function (text) {
//do stuff
);
}
})();
This kind of assumes that your data may change. If it doesn't you can adapt a different approach, for instance replacing the roamingFolder variable with something like:
var localSettings = applicationData.localSettings;
var localFolder = applicationData.localFolder;
Take a look at the dev docs if you need to access data from within the app elsewhere.

Related

Meteor: Best practice for modifying document data with user data

Thanks for looking at my question. It should be easy for anyone who has used Meteor in production, I am still at the learning stage.
So my meteor setup is I have a bunch of documents with ownedBy _id's reflecting which user owns each document (https://github.com/rgstephens/base/tree/extendDoc is the full github, note that it is the extendDoc branch and not the master branch).
I now want to modify my API such that I can display the real name of each owner of the document. On the server side I can access this with Meteor.users.findOne({ownedBy}) but on the client side I have discovered that I cannot do this due to Meteor security protocols (a user doesnt have access to another user's data).
So I have two options:
somehow modify the result of what I am publishing to include the user's real name on the server side
somehow push the full user data to the clientside and do the mapping of the _id to the real names on the clientside
what is the best practice here? I have tried both and here are my results so far:
I have failed here. This is very 'Node' thinking I know. I can access user data on clientside but Meteor insists that my publications must return cursors and not JSON objects. How do I transform JSON objects into cursors or otherwise circumvent this publish restriction? Google is strangely silent on this topic.
Meteor.publish('documents.listAll', function docPub() {
let documents = Documents.find({}).fetch();
documents = documents.map((x) => {
const userobject = Meteor.users.findOne({ _id: x.ownedBy });
const x2 = x;
if (userobject) {
x2.userobject = userobject.profile;
}
return x2;
});
return documents; //this causes error due to not being a cursor
}
I have succeeded here but I suspect at the cost of a massive security hole. I simply modified my publish to be an array of cursors, as below:
Meteor.publish('documents.listAll', function docPub() {
return [Documents.find({}),
Meteor.users.find({}),
];
});
I would really like to do 1 because I sense there is a big security hole in 2, but please advise on how I should do it? thanks very much.
yes, you are right to not want to publish full user objects to the client. but you can certainly publish a subset of the full user object, using the "fields" on the options, which is the 2nd argument of find(). on my project, i created a "public profile" area on each user; that makes it easy to know what things about a user we can publish to other users.
there are several ways to approach getting this data to the client. you've already found one: returning multiple cursors from a publish.
in the example below, i'm returning all the documents, and a subset of all the user object who own those documents. this example assumes that the user's name, and whatever other info you decide is "public," is in a field called publicInfo that's part of the Meteor.user object:
Meteor.publish('documents.listAll', function() {
let documentCursor = Documents.find({});
let ownerIds = documentCursor.map(function(d) {
return d.ownedBy;
});
let uniqueOwnerIds = _.uniq(ownerIds);
let profileCursor = Meteor.users.find(
{
_id: {$in: uniqueOwnerIds}
},
{
fields: {publicInfo: 1}
});
return [documentCursor, profileCursor];
});
In the MeteorChef slack channel, #distalx responded thusly:
Hi, you are using fetch and fetch return all matching documents as an Array.
I think if you just use find - w/o fetch it will do it.
Meteor.publish('documents.listAll', function docPub() {
let cursor = Documents.find({});
let DocsWithUserObject = cursor.filter((doc) => {
const userobject = Meteor.users.findOne({ _id: doc.ownedBy });
if (userobject) {
doc.userobject = userobject.profile;
return doc
}
});
return DocsWithUserObject;
}
I am going to try this.

How to save things using Javascript

I am making a website where you can store financial things. Just for practise. Not to publice. So far I have making the part where you can add a new list. And fill in things. But of course if I refresh the page it will be gone. So how can I save the new made list?
You could store it in the Browser via a cookie or better, localStorage. But of course if the browser deletes the "personal data" or you use a different browser, the data is gone.
Normally you would set up a server (say, PHP) and save it in a database (e.g. MySQL), even if you use the application only on your own machine.
Try using cookies or WebStorage (localstorage or sessionstorage objects). And consider using HTTPS if you working with financial info
You could use Firebase. Works great if you're only doing small things.
Basically it allows you to store data online on their servers with the simple Firebase API.
Their tutorial should get you started:
Firebase 5 minute tutorial
I am very new to learning localstorage myself and since you said "storeing in the browser" , i guess the best comtemporary and hassle and hack free method is localstorage .
Here is a accordion i made which stores the state of the accordion(weather its open or closed).
FIDDLE HERE
JS ::
$(function () {
var initialCollapse = localStorage.collapse;
if (initialCollapse) initialCollapse = initialCollapse.split(",")
console.log(initialCollapse);
$(".collapse-headings>a").click(function () {
var div = $(this).parent();
div.toggleClass("close open");
$(".collapse-content", div).toggle("slow");
localStorage.collapse = $(".collapse-headings").map(function () {
return $(this).hasClass("open") ? "open" : "close"
}).get()
console.log(localStorage.collapse)
return false;
})
if (initialCollapse) {
$(".collapse-headings>a").each(function (i) {
var div = $(this).parent();
div.removeClass("close open").addClass(initialCollapse[i])
$(".collapse-content", div).toggle(initialCollapse[i] !== "close");
})
}
});
This might be a good starting point to understanding localstorge , but if you do a google search , you'll come across a ton of useful information such as cross browser compatibility and local storage limitation and fallbacks.

Log client browse website information in backbone.js

I'm using this code to get client information :
$.getJSON("http://www.geoplugin.net/json.gp?jsoncallback=?",function (data) {
console.log(data.geoplugin_request);
console.log(data.geoplugin_countryName);
});
Then I would like to record this information at the first time that client visit the website (session start of the website). My current project are using backbone.js, require.js, underscore.js.
Any suggestions would be appreciated. Thanks.
Assuming that you have application.js file which act as a entry point of the backbone aplication which initializes your router an all stuff, you can set the client details in the browser using localStorage.
// Retrieve the object from storage
var retrievedVar = localStorage.getItem('countryName');
if( retrievedVar == null) {
$.getJSON("http://www.geoplugin.net/json.gp?jsoncallback=?",function (data) {
console.log(data.geoplugin_countryName);
// Put the object into storage
localStorage.seItem('countryName', JSON.stringify(data.geoplugin_countryName)
});
Hence the getJSON will only be fired once when localStorage var is not set.

Lotus notes automation from browser

I have been trying to automate Lotus Notes mail fillup from a browser interface.
After refering to Richard Schwartz's answer, i came up with this piece of code using the Lotus.NotesSession class.
function SendScriptMail() {
var mToMail = document.getElementById('txtMailId').value
var mSub = document.getElementById('txtSubject').value
var mMsg = document.getElementById('txtContent').value
var Password = "yyy"
alert("1");
var MailFileServer = "xxx.com"
var MailFile = "C:\Program Files\IBM\Lotus\Notes\mail\user.nsf"
alert("2")
var Session;
var Maildb;
var UI;
var NewMail;
var From = "user#xxx.com"
try {
alert("3")
// Create the Activex object for NotesSession
Session = new ActiveXObject("Lotus.NotesSession");
alert("4")
if (Session == null) {
throw ("NoSession");
} else {
Session.Initialize(Password);
// Get mail database
Maildb = Session.GetDatabase(MailFileServer, MailFile);
alert("5")
if (Maildb == null) {
throw ("NoMaildb");
} else {
NewMail = MailDB.CreateDocument();
if (MailDoc == null) {
throw ('NoMailDoc');
} else {
// Populate the fields
NewMail.AppendItemValue("Form", "Memo")
NewMail.AppendItemValue("SendTo", mToMail)
NewMail.AppendItemValue("From", From)
NewMail.AppendItemValue("Subject", mSub)
NewMail.AppendItemValue("Body", mMsg)
NewMail.Save(True, False)
NewMail.Send(False)
}
}
}
} catch (err) {
// feel free to improve error handling...
alert('Error while sending mail');
}
}
But now, alerts 1,2,3 are being trigerrd, and then the counter moves to the catch block. The lotus notes session is not being started.
In a powershell script that I was previously looking at there was a code regsvr32 "$NotesInstallDir\nlsxbe.dll" /s that was used before the Session = new ActiveXObject("Lotus.NotesSession");. Is there something similar in javascript too, if so how do i invoke that dll.
I think I've realised where I am going wrong. According to me, upto alert("5") things are good. But since Lotus.NotesSession doesn't have a CreateDocument() method, it is throwing the error. I am not sure how to create the document and populate the values though.
Since you've chosen to use the Notes.NotesUIWorkspace class, you are working with the Notes client front-end. It's running, and your users see what's happening on the screen. Are you aware that there's a set of back-end classes (rooted in Lotus.NotesSession) instead of Notes.NotesSession and Notes.NotesUIWorkspace) that work directly with Notes database data, without causing the Notes client to grab focus and display everything that you're doing?
Working with the front-end means that in some cases (depending on the version of Notes that you are working with) you're not going to be working directly with the field names that are standard in Notes messages as stored and as seen in the back-end. You're going to be working with names used as temporary inputs in the form that is used to view and edit the message. You can see these names by using Domino Designer to view the Memo form.
Instead of using 'SendTo', try using:
MailDoc.Fieldsettext('EnterSendTo', mToMail)
Regarding the Body field, there's no temporary field involved, however you haven't really explained the difficulty you are having. Do you not know how to display the interface that you want in the browser? Do you not know how to combine different inputs into a single FieldSetText call? Or are you just dissatisfied with the fact that FieldSetText can't do any fancy formatting? In the latter case, to get more formatting capability you may want to switch to using the back-end classes, which give you access to the NotesRichTextItem class, which has more formatting capabilities.

What's the best way use caching data in js on client side?

My application receives data from the another server, using API with limited number of requests. Data changing rarely, but may be necessary even after refresh page.
What's the best solution this problem, using cookie or HTML5
WebStorage?
And may be have other way to solve this task?
As much as cross browser compatibility matters, cookie is the only choice rather than web storage.
But the question really depends on what kind of data you are caching?
For what you are trying, cookie and web-storage might not be needed at all.
Cookies are used to store configuration related information, rather than actual data itself.
Web storage supports persistent data storage, similar to cookies but with a greatly enhanced capacity and no information stored in the HTTP request header. [1]
I would rather say, it would be stupid to cache the entire page as cookie or web-storage both. For these purposes, server-side caching options might be the better way.
Update:
Quoting:
data about user activity in some social networks (fb, vk, google+)
Detect the web-storage features, using libraries like mordernizr and if does not exists fall back to cookie method. A simple example
if (Modernizr.localstorage) {
// browser supports local storage
// Use this method
} else {
// browser doesn't support local storage
// Use Cookie Method
}
[1]: http://en.wikipedia.org/wiki/Web_storage
I wrote this lib to solve the same problem:
Cache your data with Javascript using cacheJS
Here are some basic usages
// just add new cache using array as key
cacheJS.set({blogId:1,type:'view'},'<h1>Blog 1</h1>');
cacheJS.set({blogId:1,type:'json'}, jsonData);
// remove cache using key
cacheJS.removeByKey({blogId:1,type:'json'});
// add cache with ttl and contextual key
cacheJS.set({blogId:2,type:'view'},'<h1>Blog 2</h1>', 3600, {author:'hoangnd'});
cacheJS.set({blogId:3,type:'view'},'<h1>Blog 3</h1>', 3600, {author:'hoangnd'});
// remove cache with con textual key
// cache for blog 2 and 3 will be removed
cacheJS.removeByContext({author:'hoangnd'})
Here is an example of caching data from JQuery AJAX. So if you only want to make the call when you don't have the data yet, its really simple. just do this (example). Here we first check if we have the load information (keyed on line, location and shipdate), and only if we dont, we make the AJAX call and put that data into our cache:
var dict = [];
function checkCachedLoadLine(line, location, shipDate, callback) {
var ret = 0;
if(!((line+location+shipDate) in dict)) {
productionLineService.getProductionLoadLine(line, location, shipDate, callback);
}
return dict[line+location+shipDate];
}
...then in the call back write the value to the cache
function callback(data) {
if (!data) {
document.getElementById('htmlid').innerHTML = 'N/A';
} else {
document.getElementById('htmlid').innerHTML = data[0];
dict[data[2]+data[3]+data[4]] = data[0];
}
}

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