I'm quite new to web applications and have decided to create a single page web app hosted on Heroku.
My understanding of this web app is as follows:
Client side (AngularJs) has input text box, once button press it requests server side endpoint
Server (NodeJs) uses data from client to call external API (e.g imgur API) and returns json
Server processes json and responds to client with information
Client uses server response to render user interface
Main Concerns
Best practices for external API calling: Should I have an API wrapper class that allows me to call custom methods that return specific external api calls?
How should I handle http error responses?: I understand that NodeJs is async by nature and all http calls are done async as well. If there are multiple responses, error or success, how do I go about handling them all without doing a custom set of ".error()" and ."success()" methods for each call?
Furthermore
I cannot seem to find a good reference material for a simple NodeJs back end like the one I described. Please direct me if there are any.
I recommend looking at this Scotch.io article for creating a Single Page MEAN Application:
Setting Up a Single Page MEAN Application Starter Kit
Related
I have this node script where it does an API call and receive the response. So what I want to do is to make a UI that controls when the script works. For example when I click a button (HTML) the script starts and then prints the response into a textbox. Is there any way to do this?
You need something to render the HTML and send a message to your Node.js program and your Node.js program needs some way to understand that message.
The most common approach would be to write a web service (usually using Express.js unless you are using React/Vue in which case Next.js/Nuxt become more interesting) and then communicate with it using Ajax (typically the fetch API). Other options would be form submissions or web sockets.
Less common would be to use a framework such as Electron.js or OpenFin to run a desktop application with an embedded HTML renderer. They then have their own APIs to communicate with the Node.js portion of the application.
I have a web application with a client that receives data from a server. I have the data in NodeJS, but I want to pass the data to a Javascript file. The Javascript file is included in a HTML file, so I can't make the files communicate with eachother.
I am new to NodeJS, so it can be a stupid question, but anyones help is appreciated
This is for a project where I need have a data stream, and I need to pass it into a web application. I tried to pass the data to different page inside my application and then I tried to get that data on that page inside my web application via Javascript, but I couldn't make that work. I'm not even sure if its possible at this point.
Your node server can't communicate with your front-end without a specific way of communication like websocket, you have many other way to communicate with your front-end as node-server, take a look at server send event for example.
By the way your front-end can call your node server more easely with a get request as said #tomerpacific in comment.
For that you have to open a route with your express app. Routing with express
And for call it on a GET request, for that you can use the XMLHttpRequest, and if you have implemented jQuery on your front, you can use Ajax jQuery.
I have written a web app (Single Page application) which has only frontend technologies involved (Vuejs) and when I compile it, it will ultimately generate web pages (only HTML and JS). I can run this app anywhere by opening the index page.I am consuming REST API powered by oAuth on this SPA (making direct Ajax call to REST API endpoints).
But the problem is, My lead developer is saying the SPA must be powered by back-end service (Server) for example nodejs, apache. And the backend should make call to the REST APIs not directly Ajax calls from the browser (Frontend JS ajax). My SPA app runs anywhere and works perfectly on browsers even without any server.
My question is, do I really need to render and run my SPA using webserver, whats the reasons behind making my SPA (Plain html, js) app server powered??
Also please suggest me, if people simply write app using JS and HTML (pure front end) and upload on the server and point a domain name to that html-js web app which will be consuming remote REST APIs.
Thank you for making my doubts clear in advance.
I have remote REST API provider, suggest me best way to write an SPA to consume that remote APIs.
There may be some reasons to setup a back-end service, for example:
Hide REST API endpoints
Setup your own caching / throttling / failovers etc. to REST API endpoints
Override / control REST API responses / requests
Still, you can use only pure html+js SPA, but adding back-end service gives you additional options, not possible to achieve on front-end.
I have created my blog as a single page application using mithril framework on the front end. To make queries I've used a rest API and Django at the backend. Since everything is rendered using javascript code and when the crawlers hit my blog all they see is an empty page. And to add to that whenever I share a post on social media for instance all Facebook sees is just an empty page and not the post content and title.
I was thinking of looking at the user agents and whenever the USER-AGENT is from a crawler I would feed it the rendered version of the pages but I'm having problems implementing the above method described.
What is the best practice to create a single page app that uses rest API and Django in the backend SEO friendly for web crawlers?
I'm doing this on a project right now, and I would really recommend doing it with Node instead of Python, like this:
https://isomorphic-mithril.mvlabs.it/en/
You might want to look into a server-side rendering of the page that crawlers visit.
Here is a good article on Client Side vs Server Side
I haven't heard of Mithril before, but you might find some plugins that does this for you.
https://github.com/MithrilJS/mithril-node-render
This might help you : https://github.com/sharjeel619/SPA-SEO
The above example is made with Node/Express but you can use the same logic with your Django server.
Logic
A browser requests your single page application from the server,
which is going to be loaded from a single index.html file.
You program some intermediary server code which intercepts the client
request and differentiates whether the request came from a browser or
some social crawler bot.
If the request came from some crawler bot, make an API call to
your back-end server, gather the data you need, fill in that data to
html meta tags and return those tags in string format back to the
client.
If the request didn't come from some crawler bot, then simply
return the index.html file from the build or dist folder of your single page
application.
I have a JSP webapp developed in Eclipse as a dynamic web project.
we use a third party web application that invokes my application, I need to validate that only the requests that come from that application are allowed to create a new session in my application.
I´m tring to do it with javascript and thinking , as a last resource, to use a Filter class to know the request origin and define the behaviour.
the problem is that the user requires that the operation is done on the client side, meaning I have to use javascript or similar, I have read about document.referrer on JS, but so far nothing is shown on the console.
Anything that you do in the client using JS for handling sessions wouldn't be secure as it can be easily modified by a malicious user. Also, using the referer or any other http header params would be insecure as they can also be easily spoofed.
If this third party application is directly calling your application I imagine that you have some degree of control over it. Can you access and modify its source code or are you just using configuration params?
Ideally the third party application would use an authentication token on each request that it makes to your application. And these authentication requests as well as all the session handling logic would always be handled on the server side.