I have a .js file on the client side that I want to send to a MongoDB instance for server-side execution. Is this something that's possible with the Java driver?
As far as I've read, and been able to understand, doEval() can execute a JS stored procedure on the MongoDB server, but that's the part I am trying to avoid in this case; storing it server side.
So instead of:
db.doEval("myStoredFunction()")
I want to do something like:
db.doEval("function() { /* do some stuff */ }
Am I out of luck here or have I just not yet found the functionality I'm looking for?
Related
so I've looked around quite a bit now and wasn't able to find quite the use case I think I am confronted with.
For some background:
I'm fairly new to JavaScript and have never had to call any other program/script from it. Now I did develop a Python script that pulls some data from online sources, formats it and dumps it into JSON files. In order to display this data in a proper way I figured I would use Electron.
While handling the JSON files is completely fine (would be quite sad if it wasn't I guess), I need to be able to call the Python script updating the data from my Electron UI. As everything is local, I hoped, that there would be an easier way, than setting up some server for the Python script to run on, just to be able to trigger its execution from my Desktop App. This is especially true, as I don't even need to get or process any returns, I just want to trigger the execution of that script.
So the question now is: is there such an "easy" way to execute Python scripts from an Electron/JavaScript based locally saved Desktop app?
Thanks in advance for any answers!
Like a previous commenter mentioned, you should be able to follow this SO answer in Node.js (which is what Electron uses).
To expound upon that answer just a bit, I'd recommend using the built-in Python JSON utility to dump JSON to the standard out (just printing out the JSON string), and the using the built-in Node.js JSON utility to parse that JSON string into a javascript object for use in your application.
Alright, so after being redirected to this thread, which I can only recommend reading through if you have an interest in this issue, I took their solution and altered a little, which took me a bit of time, due to some confusion, which I now would like to spare you guys!
To re-introduce the issue: The goal is to call a python script from a JavaScipt/Electron based UI. The python script only needs to be executed, but it needs to happen onClick, as it is an update function.
Now this is the code I used:
const exec = require("child_process").exec;
function triggerUpdateAndRefreshFooter() {
exec('python relativePathToScript/update.py',
function(error, stdout, stderr) { //callback function, receives script output
refreshFooter(); //don't use the output, but I could here
}
)
}
I did have some issues figuring out all of that const stuff in the other thread, as well as having to guess IF I could just execute my script in a separate function. In the end this did work!
I hope this was helpful!
I have a JavaScript file on my server that contains a function. I would like to develop a REST Api to connect to this server, run the JavaScript function and send back the output.
Is it possible to call a JavaScript function from a php file?
I read this but it doesn't answer my question, because my js file is hosted on the same server as the php file.
Is the V8Js extensions what I am looking for?
Edit
The js function looks like this:
function (line, userWeight, weightunit){
//logic is here
var computed = {
userLengthFtin: userLengthFtin,
userLevel: userLevel,
proId: line['id'],
proLengthFeetin: proLengthFeetin,
proThick: proThickFtin,
weightunit: weightunit
};
return computed;
}
Is it possible to call a javascript function from a php file ?
You would need to hand things over to some other software which can execute JS. This might be through shelling out or it might be though a library such as Selenium or the V8js library you found.
Whatever you choose, it would need to be able to handle the particular needs of the JS (e.g. if the JS expects to be embedded in a webpage with access to a DOM and all the APIs provided by a web browser, then you couldn't simply run it with Node.js).
It would probably be simpler to rewrite the function in PHP.
I have been using SQL for quite a while now, for a node.js project, I wanted to make the package smaller, and easier to manage, I thought by getting rid of MYSQl I can have put the database as part of the server, using a CSV file, or or something similar, and a variable array, how could I archive this?
I am yet to try any code, but this is how I am planning on going about it at the moment:
A basic express web server using the GET/POST requests, import a CSV file to a array, then do a basic variable comparison, like say, if (vararray === "foo"){
return "foo" exists in the database.}
I am still relatively new to javascript.
I need to be able to execute a shell command through javascript, similar to the php function "exec()". I understand that this may be impractical in javascript because of security reasons, but my javascript code is running on the server, and no clients have direct access to the file.
Users make a request to the server for some data, and the server-side javascript code is called. From the javascript file, I need to execute a program in order to gather data based on user input, then pass this data back.
If this isn't possible in vanilla Javascript, please point me towards a library or tool that can do this, preferably in javascript/frameworks on javascript.
JavaScript has no 'exec' function like PHP does. It's all because JavaScript runs on the client and don't have access to the server part.
However you can create PHP page and send AJAX requests to it to execute particular command.
ALTHOUGH, you need to be VERY, VERY and VERY cautious about which commands to run.
It's very dangerous to do like that. I don't advice you to do like that, however, it's possible.
Good luck!
If it's client side - You can't
If it's node.js:
var exec = require('child_process').exec;
child = exec("command", function (error, stdout, stderr)
{
// handle the output
});
This might be what you're looking for: https://github.com/arturadib/shelljs
Or, if you want to have direct access to commands, perhaps this will help: http://nodejs.org/api/child_process.html
I'm trying to write a very simple example application to familiarize myself with using MongoDB. Essentially, I'd like to have a single web page which queries a local MongoDB server, adding and removing content dynamically using jQuery. I have no problem at all throwing together the page layout and the jQuery, but I'm getting more and more confused by the MongoDB part of the equation. I understand that MongoDB is a server and runs remotely from the client, but for my example, I simply want to be able to query quickly and easily from client-side in-browser JavaScript:
$("#toggle").click(function() {
if ($(this).is(":checked") {
// add items from mongodb
addItems(mongodb.test.find({ age: { $gt: 5 }}));
} else {
$("#results").hide();
}
});
Is there a way to interface with MongoDB this way?
You need a driver to connect to a MongoDB server. The list of drivers is here:
http://www.mongodb.org/display/DOCS/Drivers
There is a JS driver, but only for server side JS - specifically node.js
Bottomline, you can't connect directly from a browser. You need a server side component.
As #balafi states you need a driver.
MongoDB does have a REST interface and infact there are drivers such as Mongoose that designed to create a fully functional REST interface for MongoDB.
This could be the route to go if you want to use MongoDB without all the hassle of setting up a server end. This way you would just ping a POST or GET call from JQuery with the specified params you want.
You can find more information on the REST interfaces here: http://www.mongodb.org/display/DOCS/Http+Interface
However I should warn you the built in one for MongoDB is extremely lacking and is only designed for extremely simple queries.