As the title suggest. I'm trying to figure out where I should cache data in my node.js application.
I'm using a express.js and controllers to handle the routes in the application. The controller for a particular route will get data via the model layer using REST API and then it uses handlebars for the view rendering on the server.
For this particular route, I'm displaying a menu and the data I have got for this has been done in the model and a remote REST call.
When the user select different items in the menu, I do not want to make a new REST call to get the same data for the menu again, I just need to get the data for this menu once since it will never change.
I need to find out a way to cache it, but do not know where I should implement it?
Best Regards
You could just cache the response from the REST API or DB lookup using a memory-store like Redis or Memcached, both have good modules available on npm - (Redis, memcached).
You would need to attempt to fetch the data from the memory-store (in your controller), if no matching data was found, you would make the request to the API or database to get the data, and then store it in your chosen memory-store so future requests will hit the cache.
note: There are also some pure JavaScript caches available such as memory-cache or lru-cache if you don't want to add an additional application.
Related
Let's say, hypothetically, I am working on a website which provides live score updates for sporting fixtures.
A script checks an external API for updates every few seconds. If there is a new update, the information is saved to a database, and then pushed out to the user.
When a new user accesses the website, a script queries the database and populates the page with all the information ingested so far.
I am using socket.io to push live updates. However, when someone is accessing the page for the first time, I have a couple of options:
I could use the existing socket.io infrastructure to populate the page
I could request the information when routing the user, pass it into res.render() as an argument and render the data using, for example, Pug.
In this circumstance, my instinct would be to utilise the existing socket.io infrastructure; purely because it would save me writing additional code. However, I am curious to know whether there are any other reasons for, or against, using either approach. For example, would it be more performant to render the data, initially, using one approach or the other?
Technology Information: ReactJS + Typescript for the frontend. REST API built with nodeJS+express that stores data in a Cloud Firestore database. The frontend React application retrieves data using the REST API.
State Management on the Frontend: I'm currently using React hooks for state management. useContext is used for managing global state (user/session information), and useReducer is used for route level state. The useReducer hook is called by the top level component in any given route.
Advice Requested:
If the user takes an action with the UI, I want to update the local state and show the appropriate changes in the UI instantly. I want to make sure the data gets saved to our backend, and only display an error message if we failed to save the data.
What's the most seamless way of handling data synchronization in this case? What's the best architecture here?
Should I make calls to the REST API from within each action in the
reducer?
What's the cleanest way to implement this throughout a large application? How should I organize my code for data synchronization?
Along the same lines, if I want to listen to changes to the user
object in the backend, and reload the user's information that's
stored in global state using the useContext hook, how should I try
to do this?
P.S. I love how seamlessly Asana syncs & saves your data. I'm wondering what are the best practices here if I want to have that seamless of an experience.
What is the best way to persist user-generated data with NodeJS, Express, and MongoDB?
I'm building my first web-app using this stack (with bootstrap HTML/CSS and JS for the frontend) and I've realised that I need a data-binding solution. I'd rather avoid a complete rebuild of my front-end so it seems like React will be the best option, but I'd rather find out now if I'm missing something obvious.
The app will allow users to create 1-n documents, generate 1-n new components within them, and edit 1-n content-editable elements within those components.
I'm at the point where I've built the server, db, and frontend and the users and documents persist, but the components and their content does not.
The functionality I would like is that, when a user generates a new element or exits the contenteditable area of that element, any changes they have made will persist. I'd like to achieve this without a bazillion API calls.
Any assistance appreciated.
You may create page description in markdown and then render it to react components.
For example you can check https://www.gatsbyjs.org/ plus Remark Custopm blocks plugin - https://www.gatsbyjs.org/packages/gatsby-remark-custom-blocks/
I'm relatively new to webdevelopment and have been using ArangoDB for most of that limited experience. I have a basic understanding of Node.js and creating express based CRUD apps with ArangoDB as the database.
I'm getting to a point though where I'd like to have the ability to query the database from inside the client. Say I would like to have a datalist-type element where the user types words into a searchbar. I'd like the ability to query the database from there rather than having to query the database for all of its files prior to creating the datalist. I have not found a single mention though of using database queries from the client side. I can't imagine that this is not possible. Surely when I search wikipedia through the search bar and it provides me with options I didn't just receive the entire wikipedia documents list upon loading the page? Please steer me in the right direction, I don't know how to tackle this problem.
Have a look at how to build dynamic forms, this will allow you to perform AJAX style calls from the browser window to a back end REST API service. This will allow your back end web service to gather the data for the response (from ArangoDB if required), and respond with that data, most likely in a JSON format.
Your UI can then take that response and dynamically update components in your DOM so that the user can see the data injected into the page without a page reload action taking place.
https://www.pluralsight.com/search?q=ajax is a great place to start.
Alternatively you can have a look at free content like https://www.youtube.com/watch?v=tNKD0kfel6o
In my Angular app, I want to display a table which contains the following
a) URL
b) Social share counts divided by different social networks
Using Sails.js, I already have the api created for the URL when the results show up, I can display the URL now I'm confused how to get the appropriate social counts showing right besides
Here's the API I'm using: https://docs.sharedcount.com/
by itself, I can see the JSON it produces
But here are my questions:
Should I create a new api (model/controller) for social count data or include it in my model where I have the 'url' action defined?
If I create a new api or include the social_counts as an action in the current, what would my JSON query look like? to retrieve the URL's, I'm using default API blueprint that Sails provides, so:
http://www.example.com/url/find?where={"title":{"contains":"mark"}}
Struggling a bit in terms of the thought process, would be great to get input on this
It depends on your app. is your app will store that data or just consume it? If it need to store, of course you need the API. In purpose for modification or aggregating the data for example.
No, you can't do that. That shortcut method only works if you have the data in your database and let the Sails Waterline ORM and Blueprint API served it.
Perhaps, if you only need to consume the data from that Sharedcount API, you didn't need to use Sails as a backend, in this context. Just use Angular as a client of that API. Except if you need to modify the data first and store it in your own database, so Sails will helps with it's Waterline ORM and Blueprint API.