I included a module in my js file. Now i defined a button in a ejs file, which calls a function in an external js file from the public folder. How can i use the module in this function?
I tried to pass the module as a parameter, but i didn´t work. Is this even the right way to use this module in my external file?
the route js file
var express = require("express");
var router = express.Router();
var R = require("r-integration");
/* GET home page. */
router.get("/", function (req, res, next) {
res.render("Upload", { title: "Upload", para: R });
});
module.exports = router;
my ejs file with the button which calls the function loadScript()
Here i also tried to pass the paramter para to the const rModule
<!DOCTYPE html>
<html>
<head>
<title><%= title %></title>
</head>
<body>
<button onClick="loadScript()">Test Skript</button>
</body>
<script>
const rModule = para;
</script>
<script src="/javascripts/rScriptTest.js"></script>
</html>
the external js file from the public folder.
But here it says, that rModule is not defined.
function loadScript() {
let result = rModule.executeRScript("./RScripts/test.r");
console.log(result);
}
You can't pass a function though an EJS template. It won't serialize cleanly.
You need:
A JS script/module that will run on a browser
A URL for that file (usually provided with express.static)
You fail at the first hurdle. The module you are trying to use describes itself thus:
This is the R-integration API which allows you to execute arbitrary R commands or scripts directly from the node JS environment. This integration works on Windows and GNU/Linux based systems and uses system calls to access the R binary.
There is no way that it is going to achieve that without using Node.js-specific APIs that are not available in the browser.
You could write a web service in Node.js and interact with it using Ajax instead.
I'm using a Verto library in my nodejs console based project - I've added all necessary references to main.js file - something like this:
const jsdom = require("jsdom");
const $= require('jquery');
const verto= require('verto/src/jquery.verto');
when I use an HTML file and use these references as a script in the HTML file my project works fine .but when excluding the HTML file and changing the project to console-based it gives an error related to veto.init.
I'm loading a local HTML file in my WebView and executing my JS-Function like so:
webview.evaluateJavascript("start();", null);
It works as long as I have the function declared in <script></script> tags in the HTML file.
...
<body>
<script type="text/javascript">
function start(){
}
</script>
</body>
...
But now I'm first using Webpack to bundle my Javascript code into a single JS file and store this in the assets folder of my app and load it like so:
<script type="text/javascript" src="file:///android_asset/js/bundle.js"></script>
The new bundle.js file contains the start function but now I can't call it, because it's not defined.
What I'm missing here?
EDIT: Ok my function is only accessible in the bundle.js. There are multiple ways to make it work, as I want:
Define global variable with webpack
I choose the following solution to make my function accessible in the global context:
window.start = function() {
}
I am trying to simply access a JavaScript file from within an HTML file using the script src attribute, and I have been unable to do so. Both files are in my functions folder.
I have the following Cloud Function index.js file in my functions folder:
const functions = require('firebase-functions');
const db = require('./admin');
var viewerApp = require('./viewerApp');
exports.view = functions.https.onRequest(viewerApp);
the viewApp.js file looks like this:
const express = require("express");
const fs = require('fs');
const viewerApp = express();
module.exports =
viewerApp.get('/:collection_name/:id', (req, res) =>
{
var viewerHTML = fs.readFileSync('./viewerApp.html').toString();
var id = req.params.id;
var collection_name = req.params.collection_name;
var rendered_HTML = eval(viewerHTML);
res.send(rendered_HTML);
}
)
You will notice the eval(viewerHTML) statement, which refers to a separate html file called viewerApp.html, which basically contains a template literal and looks like so:
<!DOCTYPE html>
<html lang="en">
<body>
...
</body>
</html>
(if someone has a better suggestion for separating the HTML into a separate file while being able to use ${variables} that would be helpful as well, as eval() is not ideal and perhaps is part of what is causing my problem)
The above works fine, except that I cannot figure out how to reference a JavaScript file located in the same functions folder, which means I would need to include all my JavaScript in the viewerApp.html file, which will be a mess.
I have tried all these possibilities in the viewerApp.html file (to try and refer to a JavaScript file called test.js):
<script src="./test.js"></script>
<script src="/test.js"></script>
<script src="test.js"></script>
<script src=test.js></script>
All of the above yield the following error in the console:
Uncaught SyntaxError: Unexpected token < test.js:2
(I get the same error if I try and refer to a filename that doesn't exist so I suspect a problem in the file path or limitation on the ability to access the local file system)
I don't know what to make of the error being related to a < character, as the content of test.js is simply:
console.log("logging happened");
Any assistance would be MUCH appreciated. Thank you!!
The problem in the end was that I did not initialize and configure firebase hosting which seems to be what allows html/js/css and other static files to be accessible in HTML returned from the cloud function. Once I did that and setup the public folder, I was able to refer to the test.js file by putting it in the public folder. That plus addition tweaks to the rewrite section of the firebase.json file, and I was all set. Following this video helped a lot and contains all the required steps.
I have a really simple website (ASP.NET core) that is a single .html static page and 6 .js files.
In one of the js files are some data that is based on my configuration:
localhost
dev
production
right now, it's hardcoded for my localhost.
Is there way that I can build/package the simple app so that if i say dev or prod in some command line arg, it replaces those values with something from somewhere else?
eg.
in main.js:
var environment = "localhost";
var rooturl = "https://localhost:43210";
and lets imagine i wish to build to my dev server...
var environment = "dev";
var rooturl = "https://pewpew.azurewebsites.com";
Is this possible? To keep things simple, assume I know nothing of JS tools and processes. (it's actually the truth, but lets not tell anyone that).
Update (further clarifications):
with 1x static html file and 6x static JS files, I have a static website. So i'm hoping to generate the js files as static files (still) but with the environment data already compiled in it.
you can use some build tools like grunt. where you can define build task which takes the environment parameter and change the variables to the desired values.
another (more simple) way is to dynamicaly create main.js (with dependency on the environment) file with your backend and the frontend will load it when it starts. src of the script tag can be the asp script, where the output is javascript
This is a snippet from a project in which I do just that. I replace various place holders with values stored in the environment variables.
This example is based on a linux environment, so I used sed to modify the file in-place, however you could just as easily read the file into memory, do the replace and write it back to disk.
grunt.task.registerTask('secretkeys', 'Replace various keys', function() {
var oauth;
try{
oauth = JSON.parse(process.env.oauthKeys).oauth;
}
catch(e){
oauth = {google:{}};
}
var replaces = {
'==GOOGLECLIENTID==':oauth.google.client_id || '{**GOOGLECLIENTID**}',
'==GOOGLESECRETKEY==':oauth.google.client_secret || '{**GOOGLESECRETKEY**}',
'==SECRETKEY==':oauth.secret || '{**SECRETKEY**}',
'==LOCALAUTH==':oauth.login,
};
const child = require('child_process');
grunt.file.expand('bin/**/*.json').forEach(function(file) {
grunt.log.write(`${file} \n`);
for(var key in replaces){
var cmd = 'sed -i s~{{orig}}~{{new}}~g {{file}}'
.replace(/{{file}}/g,file)
.replace(/{{orig}}/g,key.replace(/~/g,'\\~'))
.replace(/{{new}}/g,replaces[key].replace(/~/g,'\\~'))
;
grunt.log.write(` - ${key} \n`);
//grunt.log.write(` ${cmd} \n`);
child.execSync(cmd);
}
});
});
Hopefully you can modify to your purposes.
EDIT : I am reconsidering my answer, you are modifying javascript on a windows environment. You are likely better using PowerShell
(gc script.js) `
.replace("==GOOGLECLIENTID==",$Env:GoogleClientId) `
.replace("==SECRETKEY==",$Env:SecretKey) `
> script-build.js
So after re-reading your question, I realize there is a better solution that I have used in the past. My other answer is still relevant, so I'll leave it.
It may be simplest to just create a config file in the same folder.
<html>
<head>
<script type="text/javascript" src="config.js" ></script>
<script type="text/javascript" src="myscript.js" ></script>
</head>
<body>
ask me your questions, bridgekeeper
</body>
</html>
config.js
var config = {
'colour': 'yellow'
};
myscript.js
var user = prompt("What is your favourite colour?", "");
if(user !== config.colour){
alert("No BLUE! Ahhh....");
}
else{
alert("You may pass");
}
This is the technique I use when developing simple HTA apps for use around the office.
Check out envify. You can run it from the command line. https://github.com/hughsk/envify
sudo npm install -g envify
Say you have
var myVar = process.env.MYVAR;
Run from the command line
MYVAR=somevalue envify input.js > output.js
and the output js file should have
var myVar = 'somevalue';