CouchDB AJAX interaction - javascript

I'm writing a CouchDB sample. My intention is to write a web app using AJAX and deploy it in the tomcat environment. As I use the CouchDB I would like to know the way to interact with the CouchDB server. However there were few examples but I have few concerns over that.
1) As my application is deployed in a web server is it possible to connect with a CouchDB outside? Many examples uses apps which are deployed in CouchApp or Couch environment itself.
2) If so will it end up with cross domain issues. I found this in here
Connection AJAX, CouchDB and JavaScript
However will this be a problem? Is this the correct way to achieve this?
3) To omit above issues is it possible to use some server side javascript implementation as an example Rhino?
http://www.mozilla.org/rhino/doc.html
4) If I use Rhino above it wont allow many java script libraries to use. How do I interact with CouchDB then? Do I have to invoke native Javascript? Cant I use something like JQuery?
5) What are the best libraries for client side to achieve my goal?
Your help is appreciated.
Thank you

Based on your need to use tomcat, I would just recommend using ektorp (http://ektorp.org/). Just think of ektorp like a jdbc driver. No need to do ajax from the user interface, or no need to use javascript from java in your server.
Ektorp also lets you annotate your java classes with the javascript couchdb needs to make views. see the example here: http://ektorp.org/reference_documentation.html#d100e753
Hope that helps.

Related

Is there a way to work with Java SE jars in JavaScript?

I have on one side an API which is written in Java and on the other side an Client which is written in javascript. Is there a way to use this API maybe together with the other Java-SE jars in Javascript, perhaps in Webstorm?
Thanks for all helps.
Your server side (Java) need to pushlish RESTful API. So client side (Javascript) can use these API.
You can check out these links to more information about RESTful: wiki,
restapitutorial
Are you talking about which kind of Client? It will be a regular browser client? If so, there is no way to do it unless to make server calls using post, rest, whatever you want.
If your client is written in node.js or jrunscript you have some tricks to do it, see these links: node-java module and jrunscript.
Regards

How to run a server side JS

I have a little question here. Is there any way to build a server side JS without any use of external software. The reason for this is I am not able to install any software on the webspace but I wanted to experiment with realtime communication with the server and another user for a game or something like this.
If someone knows a way to establish something like this I would be quite happy to hear about it.
EDIT: Guys NOT NodeJS I AM NOT ALLOWED TO INSTALL ANY OTHER SOFTWARE!
https://cloud.google.com/nodejs/
or
https://devcenter.heroku.com/articles/getting-started-with-nodejs#introduction
Those $15 a year webhosts typically don't allow you advanced customization. You need a better web hosting service that allows you CLI access to the server back end.
Running JavaScript on backend requires NodeJS runtime environment. Download it here https://nodejs.org/en/
Alternatively you can can configure an instance on Heroku and run your application there. But I would suggest to try the first one.
No. Javascript is a scripting language that was designed to work within the browser. There's no out of the box solution for you, as Javascript doesn't do server-side out of the box
However, Node.Js (and others) use Chrome's V8 engine to create an event-driven runtime environment which can allow writing server-side code with Javascript. That's your best option

Auto-complete search, is there a way to code auto complete search without using php?

I only plan to use html, mysql, javascript and jquery.
I know learning php will be a great help in the future but it will take me too long to learn everything in a week.
For the sever side I use servlets..
Thank you
As far as I know, no. Well, strictly speaking, you don't need PHP, but you will need some server-side technology.
Assuming the data you need to autocomplete exists in mySQL, and you use jQuery.ajax() or similar to get the information on the fly, you still need some data access layer in between, which is where PHP or similar comes in. Of course, if you're accessing data that has been exposed by an API, you might have better luck.
MySQL runs on your server, but the browser can't open a socket directly to it to do queries. See: How to Use Sockets in JavaScript\HTML?
So you will need something on the server that talks to MySQL and responds back to your jQuery code. I'm all with you that you don't want to learn PHP. If you already know javascript, you can use node.js on the server. It has libraries to talk to MySQL: MySQL with Node.js
You won't be able to connect to your mySQL database directly using Javascript running on the client. The only possible way I can imagine is using another database system which offers an HTTP-interface (such as Apache Cassandra) or using a plugin for mySQL which does this job (I could not find an officially supported one, maybe you got more luck). This way, you could query data using Javascript/Ajax directly from your client.
But keep attention to security concerns, such as SQL injections or handling of client connections, which gets much more complex if you are not using a middle tier (PHP, nodejs, Java, etc.) running on a web server.
You have to use any server side technology for autocomplete. Without using any server side technology you can't create autocomplete (you can do it by adding some dummy records)
I found third party plug ins to do this
devbrige,
intellesense,
jquery auto complete
http://www.techyari.in/2014/04/jquery-autocomplete-ajax-tutorial-j2ee-json-mysql.html
https://github.com/devbridge/jQuery-Autocomplete
though I am still trying to work the codes out

Connecting to couch db from a webpage

I used to use mysql databases and a php backend for my web applications. Now that I am diving deeper into the the javascript world I am looking for a more compatible way to store my data. I like the idea of writing everything in one language, and javascript seems to be capable to make that job.
I started reading about couchDB and the JSON/javaScipt approach seems to fit perfectly to my needs. My question is now, which would be a convenient way to connect to the database from my pages.
I found this post, which explains how to connect to a couchDB directly from a client-side javascript using a library called couch.js. The post is quite a few years old and the library I cannot find anywhere in the web. So I am asking myself If this approach is still up to date.
I was thought that one important reason for using a server backend is to provide a security mechanism to protect the database authentification process. So: Is it generally secure to save an (encrypted) db pwd in a client side script?
So what I am looking for is a quite simple way to access and store json-like data from webpages. Are there any suggestions?
The hosting of the production solution should also be not that difficult and in the end not expansive, since it's rather meant for smaller projects at the moment.
If the post does not fit to the forum, let me know a better place for it..
I have been using the CouchDB jQuery Plugin for development. At first I was hesitant as well to use it due to most documentation being at least a few years old. So far it has worked really well and been very easy to use, especially if you are familiar with JavaScript/jQuery.
...
You can get the plugin from Github
CouchDB jQuery Plugin
Or you can save it directly from Futon:
http://localhost:5984/_utils/script/jquery.couch.js (where local host is your IP and 5984 is the port CouchDB is on)
Whatever you do, make sure you enable CORS on your database. There are instructions on the Github Readme page, or this script is super useful and easy to use through npm.
...
Documentation can be found here.
This reference has also been very useful for me.
...
Good luck!
I just released Slouch, a JavaScript client for CouchDB that can be used in both the browser and in node. I hope this helps!

How to connect to database in JavaScript

How can I connect to mysql DB from JS function?
I found this question:
How to connect to SQL server database from javascript?
but it doesn't work on Chrome, because they're using ActiveXObject.
Thank you.
There is no good solution on web browser side which will allow you to work with all browsers. There are many disadvantages to work with database on browser site.
First of all, you show your database structure and it is very dangerous. Imagine, how easier is to make SQL-injection while you know tables and fields?
You have to establish connection in some way using password which will be shown to third party users. Or you have to set password-less connection, which is also dangerous.
When you establish connection with database, somebody can easly execute own query what is trivial, because you are showing your structure.
I strongly recommended you to not do it on browser side.
but I have cross-domain problem, so I just need to do simple select from db
Direct browser-to-database communication is definitely not a proper solution.
If you want to get a list of values out of the db, just write a method in whatever server-side language you prefer (or need) to use, make the client-side JavaScript code call that method through its public URI and parse the response body into some data structure.
A more general solution to this kind of problems is XMLRPC (for the record, I've used it under Code Igniter / Flash ActionScript 3.0), though it's not all that simple to use.
If you need to get data from two different domains, then implement the above on both of them and make the JavaScript code call the two different URIs and combine the data (if needed).
You must use AJAX, because JavaScript itself can't connect to server. You can call some PHP script with AJAX and in JavaScript handle response from it. See jQuery.ajax().
make Ajax call from your javascript to php which connects you to database
Without some sort of plugin, or sending requests to a server side application that will access the database for you, you can't. So focus on those instead, specially server side apps.
A comment under this question
How to make a database connection
suggests that's only possible with a particular mix of Microsoft technologies specifically designed to deploy desktop-like software using a web browser. The bits mentioned there are:
HTA - HTML Applications
JScript - a Microsoft flavor of JavaScript
ActiveX objects
A link is also provided: Introduction to HTML Applications (HTAs)

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