Creating a web application that communicates with another web application seamlessly? - angularjs

I am trying to develop a web application that can communicate with another web application. App1 is an app developed using Angular.js and Struts2. This apps sole purpose is to perform search queries on several databases and returning the information about the products for the user to view. App2, the current app I am developing, will be developed using Angular.js and Flask/Python. This app will be responsible for storing the products the user selects in a shopping cart and allowing the user to make a purchase.
I am stuck as to how to get the two applications to communicate(passing login information, selected items ids, etc.) with eachother.
I have tried passing information via a url redirect (http://www.example.com/?myVar=someData&...) but Angular is giving me a lot of trouble to try and get around that. Even if I can get this to work, I think it would be insecure as data the user shouldn't know will be exposed in the url.
My second thought would be to somehow access the session data from App1 in App2 but that could also lead to security issues.
My final thought would be to some how make a call to App1 that returns a json object that can be parsed in App2 but I am not entirely sure how to pass that information along.
How can I get the two applications to communicate with each other?
Thanks for your help

In my opinion this isn't really within the scope of AngularJS. However, I believe that the best, most accepted practice for communication between web applications in this day and age is RESTful Web Services.
It's not a small topic, but once you get the concept behind it you can use it in any programming language that supports web applications (Java which I'm assuming you're using because of struts has multiple REST libraries, I prefer Jersey but that's just me).
It's also an amazing way to use your Angular front end to talk with its own back end. The entire Angular $resource framework is built around the idea of using RESTful services.
Check out this link on Wikipedia for a brief synopsis of what makes a service RESTful: http://en.wikipedia.org/wiki/Representational_state_transfer#Applied_to_web_services
Now, that applies to most of what you asked. As far as login information is concerned, that's going to depend on your security implementation. A lot of times you can put information like that in the header of a web services request, and only accept requests that come from trusted servers, etc. but there's a good bit of stuff to understand there. It's an entirely separate topic.
Hopefully this helps you get started. Let me know if you'd like more information or pointers.

Related

Multi tenancy in Spring boot and React

I am trying to develop a REST API in spring boot and having React as the frontend. React will send GET or POST requests happening on the frontend to modify the MySQL DB in the backend via REST API. In my application, A user can have multiple companies inside the application and each company data is isolated from one another. I have come across Multi-Tenancy in Spring boot. How can I do this implementation for REST API ?? How can I configure my React application for this multi-tenancy?? Is Reactive Core in spring is useful??. Any resources where I can find these answers so that I can implement it. Or any other better way to implement this use case. Please, someone help me. Google results have confused me a lot
You could read a lot about this if you focus on little more details than a broad topic search in Stackoverflow
Here is one way you can achieve your requirement.
React App authenticates your end-users
There will be an API call from UI to get the list of accessible tenants
The list of tenants will be shown in the UI like in a dropdown
The end user will choose a tenant
Once chosen, untill a change next time, you will pass the selected tenant in all the API request headers so that you are identifying the tenant context of the user that is requesting for the data.
Regarding the data-isolation, you do have a lot of options explained in stackoverflow and people have multiple approaches depending on the multi-tenancy levels of course.
The above are the steps that you could achieve in any language (java in your case)
In case of choosing whether your API's are Reactive depends on the business needs. However you should be able to weigh the differences between the aync and reactive implementations, both have their needs, so identify the requirement and choose an approach that suits.
In case you need help in choosing the right approach for a given scenario, do share with us the scenario, how you did it and what you have issue / doubt and the community will be happy to help you.

How to make Ionic app work with an API written in Laravel but still works offline

I would like to ask how to create an ionic app that talks to Laravel API but still works offline when there's no connection.
Let's say i have to write a quiz mobile app in Ionic and it requests for Laravel API to retrieve the questions as well as store the scores in db.
I'm just starting to learn Ionic and i'm really confused right now on how to approach this.
What confuses me most are:
Does the Ionic source live inside the Laravel source code w/c serves the API?
If i want the Ionic app to be installable, should the Laravel source code be included as well during the compilation process?
Thanks in advance for any help.
Your php or in general server side code is completely independent from your ionic application. If you want your app to work offline you should think about something like fetching a high number of information initially and work with this data without making any additional requests.
However your ionic app does only contain the frontend. You could implement some logic for local storage, but if you want to keep information hidden from the user (e.g. solutions) you have to put that logic on a dedicated server.
In the few details you provided, I can say the Laravel code does not live inside the ionic app. The ionic app is separate from the backend API by Laravel. You are possibly trying for a ReST based architecture where you communicate with your Laravel Server with an API. You need to keep those codes separate.
However without any internet, you won't be able to access those APIs, so you will just be able to show some static data, or you could serve from a DB and show later. For how to use the sqlite db you can look here
In your backend you can have an API like
http://example.com/api/v1/questions/1/
Which will fetch a question with options and if you want the app to have the answer for offline storage you may have that as well. When a user answers, you may check whether you have internet access and send answer and verify if you do, else you may save the answer in your DB and sync when you do have access. You can fetch multiple questions so that a user may answer multiple questions in case he/she will not have internet access.
Hope it helps. :)

Web App Architecture design with REST on Java Stack

I'm planning to build web application on top of a REST api. I have been thinking about 2 different ways to write web UI layer for controlling the views, user session management, etc.
One way : Just write everything in Javascript using Angular or similar frameworks. But, the problem I see here is, user session management and also it may not be good idea to expose everything to client. I'm thinking anybody with good knowledge of web design, can find out javascript logic and end points.
second way: Write a thin controller and user session management layer on REST in may be Spring web mvc project / Node JS, etc, and control everything from there. But, the problems I see here are, we have to have some end point lookup logic here, to map web ui request to REST end point. Everytime, we we add more end points, we have to maintain that catalog as well. Also, the JSONs will go through many transformations, and which may add some overhead.
can anybody suggest some architecture ideas for this ? Am I missing anything here ? Can we write secure Javascript web ui layer on REST ?
I was also thinking about having Message broker like RabbitMQ to scale it. Any suggestions are appreciated.
Thanks in advance.
You should first decide on how you divide responsibilities between the client and the server. What do you want the server to do, and what do you want the client to do? You already figured out that the server should hide the sensitive information, to keep the application secure. Is there anything else you need from the server? If there is a database, you probably also want to let the server handle all access to the database.
Notice that there are also alternatives such as Firebase, where they take care of the backend for you, and you focus on the front-end mainly. Might save you a lot of work on authentication, and data access.
You also need to think what kind of communication style they will be using? If it is Request-Response, then REST is suitable. If it is some kind of bidirectional messaging such as chat, I recommend to take a look at Meteor. In Meteor, you write in Javascript for front-end, back-end and mobile.
You mentioned that you're concerned with having to transform your Jsons often. If you do your server-side with NodeJS, this problem disappears. It's Javascript on the server-side.
There are many ways to implement an application. You can more specifics about what you're trying to do, and then we may recommend the frameworks that are better for you.

Advantages of a separate REST backend API?

Context: I'm a beginner programmer, self taught in the hope of making a SPA. I've started with JavaScript, Jquery, PHP and MySQL, and now feel pretty confident with all. I've started with Ember, and am now moving away from having a PHP API to Node. Which has then brought me closer to Meteor... I'm aware I'll need to use Mongo instead, but having an integrated front and back seems to be sensible and have some advantages.
So my question is what are the advantages of having a separate REST backend API (eg Express) rather than an integrated front/back (eg Meteor).
One that springs to mind is that my app will be tablet/pc based, but in future I'll want a different mobile version, so I'd be able to use just use the same API. I'm conscious that the above question is the main concern with this stack question, but perhaps if a meteor developer could clarify whether this is indeed a concern.
Thanks in advance!
well for me you'll get a lot of advantages using a rest API, they are lightweight, extensible and overall reusable.
today it's a trend to use a vertical architecture that means having a RestFul service with a single responsibility, why because it scale better and it's easier to assign a team to an api, so that way you'll be able to manage several teams and apis in a very ordered way. This is probably how Twitter, wunderlist and other companies works, because it's a solution to scale better.
take a look to this talk by Raffi Krikorian he was the head of architecture of Twitter for a while is a little bit old but it worth every minute and to illustrate some of the advantages.
Also you can look at the diagram below, I did while ago it explains the differences between the MVC and API first type of architecture.
I've authored one rest app using angular and rest services and it has been a very nice experience to me there's no way back.
good luck
Meteor doesn't really "integrate" the front (client) and backend (server) as you describe. It still maintains them as two separate layers. The beauty of meteor (aside from the insanely awesome reactivity) is that it uses Javascript everywhere, instead of using JS on the client and some other language on the server, so you can use the same APIs on both the front and backend. Although Meteor does snazzy things like let you write client and server code in the same file, it still requires you to distinguish between the two, and server code is still stored only on the server and client-side code is still served down to the client.
Meteor is still young, but the developers and community are very active, and everything you described can be achieved with it at this point. I've been working with Meteor for about 6 months now, and it hasn't let me down yet. I'm working on a production-level application that also requires exposing a REST API for consumption in mobile apps, which I'm doing quite successfully with Meteor (I just updated a user profile using a REST endpoint from an Android device and watched it change in the Meteor app in realtime. So cool!).
I was using this great package, RestStop2, for building REST APIs in meteor, but it was unfortunately deprecated, so I released an updated version. Check it out for an example of building REST APIs in Meteor. It's available through the Meteor package manager: https://atmospherejs.com/nimble/restivus
So to answer your question, you always want to separate the REST API into it's own layer, but that is entirely possible with Meteor. To make it clear, you would never consume this REST API from within your Meteor app. Meteor uses DDP (not HTTP), which gives you a much more direct connection with your server, so you're doing something wrong if you're accessing data on your Meteor server from a Meteor client via HTTP. Of course, with Meteor, you have the advantage of being able to use existing code from your REST API.
There's a really good write-up that explains some of the considerations of writing a REST API in Meteor: http://www.meteorpedia.com/read/REST_API.
The design of a architecture separated in layers like frontend, backend (Rest Api) and DB, is for obtain a better a scalability, reusability and logic separator of features of the application. For example:
Today make a web applications separated in 3 layer (frontend, backend,
and databases), if tomorrow you wanna do a mobile application you can
develop the application like a extra project in the frontend layer,
but use all the features developed in backend. Then the frontend
application not need servers why run inside every device, but maybe
the load in the backend servers increase, and you only need add 1 more
server in the backend layer.
Its a little example, but is the most common case in this new era of mobile applications.
Remember always this in MVC architectures:
Frontend: Always call services from the backend, render the view, and capture data. Sometimes make a litle logic.
Backend: Receive the request, apply all the business logic, read and write operations in databases, and return a response preferred in json format.
Model: store data, backups, slaves, etc.
PD: If you use meteor in this example you gonna need to make a api Rest to develop the mobile application.

Angularjs and php as backend

I've created a angularjs app which uses php for handling the database queries and enforcing an authentication schema.
When the user logs in into the app, he does so in php and php fetches the user data into a session. Then angularjs issues a http post request to a php page to read the fetched data.
After that, whenever a user asks for data, angular issues a post to a php page.
I'm considering using a framework for doing the authentication and the database queries in a better way. My security knowledge is primitive and I fear that I have mistakes in my code.
After doing a research I found laravel which seems straightforward and easy.
Now my questions are:
Can a php framework such as laravel do these things for me?
Is there something else I could use to have people authenticate and making sure that they are doing the CRUD operations they are authorized to do?
What are the keywords I'm searching about, is it routing, is it php restful? I'm asking in order to do further research on the matter.
Is there any other way in which a SPA could work with CRUD operations and Authenticating in a "safe" manner using php?
I know that the above questions are not programming questions per se, but I don't know where to ask (because I feel I cannot communicate what I want to learn about/ *that's why the keywords question above).
Thank you
There's basically two kinds of relevant "routing" both based on URLs, either client side or server side. AngularJS has the $routeProvider which you can configure so when the location changes (handled by $location) the client side template and controller being used also change. On the server side you may have redirects or "routes" that map a URL to a particular PHP file (or Java method) where at the destination it parses the incoming URL to get extra information/parameters.
I know nothing about laravel, but googling laravel and authentication came back with this which looks promising:
http://bundles.laravel.com/category/authentication
I also know things like Zend framework provide many similar options for plugging in some authentication code.
Ultimately if you're writing the CRUD operations something in your code is going to have to do deal with the role based execution of code or access to data.
RESTful is it's own thing. At a very basic level a RESTful interface uses HTTP "verbs/vocuabulary" like PUT, POST, DELETE, GET (part of the request headers which is just data that comes before any body data in the request) are given special meaning like update an entry etc. It's mostly orthogonal to the issue of authentication though if you do true REST I'm not sure if using the SESSION for maintaining authentication would be allowed since it's not completely stateless in that case (anyhow just an academic argument). Point being you can use the other ideas of REST or use some implementation that is "RESTful" and it can be written in any language or you can choose not to do this, either way you still have the issue of controlling resources (functions/methods/data) that you want to control and this issue is not the same as choosing RESTful or not RESTful (if you wanted to keep true to REST for reasons of scalability across a cluster of servers etc. you could follow guidance here How do I authenticate user in REST web service?). Also to note here the $resource in AngularJS provides an abstraction above $http specifically for handling restful services.
IMHO you should be searching for two things
1 php security/authentication
2 php hacking/hacks/vulnerabilities
You can simply write your own authentication mechanism using a session to keep track of the signed in user. http://php.net/manual/en/features.sessions.php There is no difference in a SPA vs a traditional web app as far as the server is concerned, these are simply differences in the client side code.
Any security you intend on putting in place is really only as good as your understanding of that security. I wouldn't trust someone else's plugin from the internet to handle authentication for me unless time was an extremely critical factor and security not so much. One thing that you hadn't mentioned but I think is worth looking into and necessary for any of this to really be secure is SSL. If you don't have your data encrypted there is always a possibility of a man in the middle attack (someone getting the plaintext username and password as their submitted to the database) or session hijacking (someone getting the sessionid of an active session then using that to act as the original user). Basically I would suggest you keep doing research regarding best practices and personally look over any code you plan to use to be sure you understand how it's working and what kind of security it provides you with.
I also wanted to mention, though it's a bit off topic languages wise, that Java Spring has some really nice stuff for dealing with authentication and handling access to services and data. If security is a major concern I would probably strongly consider running a Java server (not to say Java has never had it's issues or that it's automatically more secure but there's a lot of production code that has withstood the test of time). There's the free Tomcat J2EE Server or IBM WebSphere if you need to massively distribute an application. If interested search for Java, Spring, Hibernate (ORM), MyBatis, Data Access Objects. Those are all the parts (some optional) I can think of you would need to put together a service layer in Java. Good intro in the video on the left of this page:
http://static.springsource.org/spring-security/site/index.html
Also SSL isn't a silver bullet, but every layer of security helps.
Kevin Mitnick said in one of his books that lots of places have "hard-shell candy security" (paraphrasing) where breaking the outer layer means you get to all the mushy goodness inside. Any direct answer I would bank will result in this type of security.
Depending on the scope of the project it might be necessary to have security professionals do penetration testing on the system to determine if there are vulnerabilities so they can be plugged.

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