I study Vue and Vuex. In the official documentation there is a simple example of using a Vuex with saving data to localStorage.
To better understand the material I studied, I decided to consolidate the knowledge into practice and write a mini application - a clone of trello (SPA).
Namely:
Create three routes:
General dashboard (/dashboard) where are boards
Board (/board) where one or several columns are located, each column has a button for
creating a task in it
Task (/:task-id) that are in columns, tasks can be moved between columns
Sidebar in which all notice with the board are displayed (CRUD by tasks and columns, changes in the status of a task, and so on.)
Sockets so that other users can see the
changes on the board in real time.
Questions!
What data should I store exclusively in the storage Vuex? Excluding authorization. It is obvious.
For what data in this application can localStorage be useful?
What should I use so that data is not discarded when I refresh the page or navigate? I can use localStorage, but hypothetically there can be a lot of data. The fourth question follows from this.
Is a better solution to use persistent remote storage on server / cloud? If so, could you give me information on how to do this? And in this case, interaction with the database is of interest, at what point is it better to save data in the database?
I'm interested in how to properly build such an application, as in a real commercial application.
I use and learn the stack MEVN
1- you can store any type of data in your store, 2 - I don't thing is useful. Because if users remove browser cache all them data will be forget. So you need configure an database for this. 3 - You need a Database and some Backend to provide your data. 4 - It's depends. if you need only for developement, you can install any things in your machine. If you need some thing more robust, could you take a cloud server. But for configure the server you need a little bit system administrator skills.
Related
I am trying to create a dashboard app for my company that displays data from a few different sources that they use. I am starting with an in house system that stores data in MSSQL. I'm struggling to decide how I can display real time (or at least updated regularly) data based on this database.
I was thinking of writing a node server to poll the company database and check for updates and then store a copy of the relevant tables in my own database. Then creating another node server that computes metrics (average delivery time, Turnover, etc.) from my database and then a frontend (probably react) to display these metrics nicely and trigger the logic in the backend whenever the page is loaded by a user.
This is my first project so just need some guidance on whether this is the right way to go about this or if I'm over complicating it.
Thanks
One of solutions is to implement a CRON job in nodejs or in you frontEnd side, then you can retrieve new Data inserted to your Database.
You can reffer to this link for more information about the CROB job :
https://www.npmjs.com/package/cron
if you are using MySQL, you can use the mysql-events listner, it is a MySQL database and runs callbacks on matched events.
https://www.npmjs.com/package/mysql-events
I have a dotnet core 2.0 API. I want to store the total number of requests and also the number of requests made per user. I can't store this information in the database, because the API connects to many different databases dynamically depending on what the user needs. Also, I can't just use logging because I want to retrieve these numbers using a request in the API.
The only thing I can think of would be using a custom JSON file, and to continually update the file using middle ware. But this seems cumbersome, and I feel like there's got to be an easier way to store small amounts of permanent data. Maybe there's a nuget package someone can recommend?
I assume you could use cache memory depending for how long you want this data to be stored.
In other case, as suggested, your only choices is a file or a database.
I'm developing an app that allows to track a mobile device instantly (live) ... I need an of advice. The application must send the location to a webservice that in it's turn records the received data in a database.
What would be, in your opinion, the best way to store the location values?
I'm new in using bigdata and I'm afraid that simple sql requests wont be able to do the work properly ... I imagine if there is lot of users and each user send a request each 1sec I'll have issue with the database ...
An advice ? Thank you very much
i think you could have a look into the geospatial queries in mongo, if you chose to go ahead with mongodb.
Refer here
And here
for the design of the database would depend on the nature of the query (essentially the read and write).
Worth having a look into
Working at Cintric we landed on using elasticsearch. We process billions of location points in real time and provide advanced analytics to our users.
We started with mongoDB and ran into a lot of troubles, eventually leading to a painful migration.
Our stack currently has mobile devices dump location updates into AWS Kinesis, which are then processed by AWS Lambda handlers, and then dumped into elasticsearch. We're able to serve, process and store 300 million requests/month for only a few hundred dollars/month. Analytics for our dashboard add additional cost but for your needs I would highly recommend checking out your options on AWS.
I am hoping to use the Diff-Match-Patch algorithms available from google as apart of the Google-Mobwrite real time collaborative text editor protocol in order to embed a real time collaborative text editor in my program.
Anyways I was wondering what exactly might be the most efficient way of storing "global" copies of each document that users are editing. I would like to have each document stored on a server that is not local to any user and each time a user performs an "operation" ( delete insert paste cut ) that the diff is computed between their copy and the server and its patched etc... if you know the Google mobwrite protocol you probably understand what I am saying.
Should the servers text files be stored as a file that is changed or inside an sql database as a long string or what? Should I be using websockets to communicate with the server? I am honestly kind of an amateur when it comes to this but am generally a fast learner. Does anyone have any tips or resources I could follow perhaps? Thanks lot
This would be a big project to tackle from scratch, so I suggest you use one of the many open source projects in this area. For example, etherPad:
https://code.google.com/p/etherpad/
Mobwrite is using Differential Synchronization technique and its totally different from Operational Transformation technique.
Differential Synchronization suppose to have a communication circle that always starts from the client(the browser), which means you cant use web-sockets to send diffs from the server directly. The browser needs to request the server frequently to get the updates (lets say every 2 seconds), otherwise your shadow-copies will be out of sync.
For storing your shadow-copies when the user is active, you can use whatever you want, but its better to to use in-memory DB (Redis) since you need fast access to do the diffs and patches. And when the user leaves the session you don't need his copy anymore. But, If you need persistence in you app, you should persist only the server-copy not the shadow-copy (shadow-copies are used to find-out the diffs), then you can use MySQL or whatever you like.
But for Operational Transformation technique there are some nice libs out there
NodeJS:
ShareJS (sharejs.org): supports all operations for JSON.
RacerJS: synchronization model built on top of ShareJS
DerbyJS: Complete framework that uses RacerJS as its model.
OpenCoweb (opencoweb.org):
The server is either Java or Python, the client is built with Dojo
I am building a full featured web application. Naturally, you can save when you are in 'offline' mode to the local datastore. I want to be able to sync across devices, so people can work on one machine, save, then get on another machine and load their stuff.
The questions are:
1) Is it a bad idea to store json on the server? Why parse the json on the server into model objects when it is just going to be passed back to the (other) client(s) as json?
2) Im not sure if I would want to try a NoSql technology for this. I am not breaking the json down, for now the only relationships in the db would be from a user account to their entries. Other than the user data, the domain model would be a String, which is the json. Advice welcome.
In theory, in the future I might want to do some processing on the server or set up more complicated relationships. In other words, right now I would just be saving the json, but in the future I might want a more traditional relational system. Would NoSQL approach get in the way of this?
3) Are there any security concerns with this? JS injection for example? In theory, for this use case, the user doesn't get to enter anything, at least right now.
Thank you in advance.
EDIT - Thanx for the answers. I chose the answer I did because it went into the most detail on the advantages and disadvantages of NoSql.
JSON on the SERVER
It's not a bad idea at all to store JSON on the server, especially if you go with a noSQL solution like MongoDB or CouchDB. Both use JSON as their native format(MongoDB actually uses BSON but it's quite similar).
noSQL Approach: Assuming CouchDB as the storage engine
Baked in replication and concurrency handling
Very simple Rest API, talk to the data base with HTTP.
Store data as JSON natively and not in blobs or text fields
Powerful View/Query engine that will allow you to continue to grow the complexity of your documents
Offline Mode. You can talk to CouchDb directly using javascript and have the entire app continue to run on the client if the internet isn't available.
Security
Make sure you're parsing the JSON documents with the browers JSON.parse or a Javascript library that is safe(json2.js).
Conclusion
I think the reason I'd suggest going with noSQL here, CouchDB in particular, is that it's going to handle all of the hard stuff for you. Replication is going to be a snap to setup. You won't have to worry about concurrency, etc.
That said, I don't know what kind of App you're building. I don't know what your relationship is going to be to the clients and how easy it'll be to get them to put CouchDB on their machines.
Links
CouchDB # Apache
CouchOne
CouchDB the definitive guide
MongoDB
Update:
After looking at the app I don't think CouchDB will be a good client side option as you're not going to require folks to install a database engine to play soduku. That said, I still think it'd be a great server side option. If you wanted to sync the server CouchDb instance with the client you could use something like BrowserCouch which is a JavaScript implementation of CouchDB for local-storage.
If most of your processing is going to be done on the client side using JavaScript, I don't see any problem in storing JSON directly on the server.
If you just want to play around with new technologies, you're most welcome to try something different, but for most applications, there isn't a real reason to depart from traditional databases, and SQL makes life simple.
You're safe as long as you use the standard JSON.parse function to parse JSON strings - some browsers (Firefox 3.5 and above, for example) already have a native version, while Crockford's json2.js can replicate this functionality in others.
Just read your post and I have to say I quite like your approach, it heralds the way many web applications will probably work in the future, with both an element of local storage (for disconnected state) and online storage (the master database - to save all customers records in one place and synch to other client devices).
Here are my answers:
1) Storing JSON on server: I'm not sure I would store the objects as JSON, its possible to do so if your application is quite simple, however this will hamper efforts to use the data (running reports and emailing them on a batch job for example). I would prefer to use JSON for TRANSFERRING the information myself and a SQL database for storing it.
2) NoSQL Approach: I think you've answered your own question there. My preferred approach would be to setup a SQL database now (if the extra resource needed is not a problem), that way you'll save yourself a bit of work setting up the data access layer for NoSQL since you will probably have to remove it in the future. SQLite is a good choice if you dont want a fully-featured RDBMS.
If writing a schema is too much hassle and you still want to save JSON on the server, then you can hash up a JSON object management system with a single table and some parsing on the server side to return relevant records. Doing this will be easier and require less permissioning than saving/deleting files.
3) Security: You mentioned there is no user input at the moment:
"for this use case, the user doesn't
get to enter anything"
However at the begining of the question you also mentioned that the user can
"work on one machine, save, then get
on another machine and load their
stuff"
If this is the case then your application will be storing user data, it doesn't matter that you havent provided a nice GUI for them to do so, you will have to worry about security from more than one standpoint and JSON.parse or similar tools only solve half the the problem (client-side).
Basically, you will also have to check the contents of your POST request on the server to determine if the data being sent is valid and realistic. The integrity of the JSON object (or any data you are tying to save) will need to be validated on the server (using php or another similar language) BEFORE saving to your data store, this is because someone can easily bypass your javascript-layer "security" and tamper with the POST request even if you didnt intend them to do so and then your application will be sending the evil input out the client anyway.
If you have the server side of things tidied up then JSON.parse becomes a bit obsolete in terms of preventing JS injection. Still its not bad to have the extra layer, specially if you are relying on remote website APIs to get some of your data.
Hope this is useful to you.