Develop an Application.

Contact me This page updated: March 2019

• Glade:
  
  Available in Mint's Software Manager.
  Too complicated, couldn't figure out how to use it.
  



• Pencil:
  
  Pencil Project
  No grid/table tool.
  



• Google Web Designer:
  
  Google Web Designer
  If you don't want Google's repository added to your system, do "sudo touch /etc/default/google-webdesigner" before installing the package.
  It's really just for building ads for mobile.
  



• Akira:
  
  SkySilk's "Akira: A Native Linux App for UI & UX Design"
  

An Electron application is (basically) a web app packaged with a (slightly old) version of the Chrome browser ...

The Electron application has a copy of the Node.js runtime, which allows you to do many of the things that a native desktop application can do, but which the security model of a web browser doesn't allow you to do, including accessing local files, integrating at a lower level with the Operating System.

HTML/CSS:	Bootstrap or Materialize or Foundation
Library everything else uses:	jQuery
UI library or framework:	Library: React or Vue. Framework: Angular (AKA "ng")
	Electron
	Electron Builder ?
Modules:	Node
Database access:	SQL.js or Electron-store
Database format:	SQLite or MongoDB
OS:	Linux.

HTML/CSS:	Bootstrap (CSS and JS), ng-bootstrap (JS)
Library:	jQuery from ng-bootstrap (JS)
UI framework:	Angular (AKA "ng")
	Electron
	Electron Builder ?
Modules:	Node
Database access:	SQL.js
Database format:	SQLite
OS:	Linux.

1. Install stuff:
   
   

   
   # if you don't have Node.js, install that
   
   sudo npm install -g @angular/cli@latest
   # got "skipping optional dependency fsevents"
   # apparently fsevents is for running on OSX
   ng --version
   # 3/2019: I got "Angular CLI: 7.3.5"
   
   sudo npm install -g typescript
   # 3/2019: got "typescript@3.3.3333"
   
   sudo npm install -g electron --unsafe-perm=true --allow-root
   # 3/2019: got "electron@4.0.8"
   
   # Name of new app can not have any uppercase letters in it !
   # cd to place where you want app dir to be created, and:
   ng new matrix-dashboard
   # Asked "Would you like to add Angular routing ?"
   #		This allows user to follow URL links to different parts
   #		of the one page of your single-page application
   #		I answered "no"
   # Asked "Which stylesheet format ?"
   #		I picked the default, CSS.
   
   cd matrix-dashboard
   
   # (I didn't realize that ng-bootstrap and ngx-bootstrap
   # are different things.  Having installed ng-bootstrap,
   # I'll stick with it.)
   ng add @ng-bootstrap/schematics
   # see warnings about peers of jquery and popper not found
   #	ignore the warnings
   #	You don't need jQuery / popper to use ng-bootstrap and
   #	you shouldn't install those manually
   # I also saw warnings about peers of angular/common and
   # /core and /forms not found.  Sounds fatal.  But online,
   # someone says as long as the installed version of Angular
   # is higher than the version in the warning, no problem.
   
   # start development server
   ng serve
   # saw messages that server is up and compile succeeded
   # now app is accessible on http://localhost:4200/
   # go there in browser, see default Angular app
   # back to CLI window, ctrl-C to kill server
   
   # add electron as a dev dependency
   npm i -D electron
   # 3/2019: got electron 4.0.8
   
   npm i -D @types/electron
   
   mkdir dist
   mkdir dist/matrix-dashboard
   
   # edit tsconfig.json file to add first line:
   #		/* angular tsconfig.json */
   
   # edit package.json file to add first component:
   #		"comment": "angular package.json file",
   
   mkdir electron
   cd electron
   mkdir dist
   mkdir dist/matrix-dashboard
   

   Directory structure that resulted:

   
   matrix-dashboard/
   	angular json files
   	do "ng build" when in this dir
   	dist/
   		matrix-dashboard/
   			app's angular HTML, JS files
   	e2e/
   		end-to-end tests
   	node-modules/
   		bootstrap
   			CSS, JS files
   		@ng-bootstrap/
   			JS files
   	src/
   		angular CSS, TS, HTML, JSON files
   		app/
   			app's CSS, TS, HTML files
   	electron/
   		TS, JSON files
   		dist/
   

   So, some trickiness going on here:
   

   • The "top-level" app is an Angular web-app, which uses a local server if you run it.
   
   
   • The Angular web-app is using CSS and JS from bootstrap, and JS from @ng-bootstrap.
   
   
   • Inside the electron directory is stuff which grabs the Angular code and node_modules, compiles it, and runs it as a desktop app in the electron framework.
   
   

   Mosh Hamedani's "Angular 4 Tutorial: Angular 4 in 20 minutes"
   Angular's "Workspace and project file structure"
   
   
   


2. Build and run Angular web-app:

   
   # cd to main matrix-dashboard/ dir
   ng serve
   ng generate service file  # one-time thing to add a service
   ng build
   # go to http://localhost:4200/ to see Angular web app running
   # page HTML source is src/app/app.component.html
   
   # ctrl-C to kill Angular server
   

   Structure of the Angular application:
   

   • Really all that should be in the body of src/index.html is

       <app-root>
         <app-yourappsname></app-yourappsname>
       </app-root>"
     

   
   
   • In app.component.ts should be the line:

       selector: 'app-yourappsname'
     

   
   
   • The main page of your app will be in app.component.html.
   
   
   • You can't use deprecated HTML in the pages. That means no "center" tags: use CSS "text-align:center" or "margin:0 auto;". Probably also no "font" or "u" tags, and a bunch of deprecated attributes.
     CodeHelp.co.uk's "What's a deprecated tag / attribute?"
   
   
   
   Places errors could be flagged/shown:
   

   • In your source-code editor as you type.
   
   
   • In the "ng serve" window when it recompiles.
   
   
   • In the page displayed in the browser.
   
   
   • In browser's debug-console for the page displayed in the browser.
   
   

   Edward Jackson's "Debugging Angular CLI Applications in Visual Studio Code"
   
   
   


3. Get electron desktop-app going:
   
   Create electron/index.html file:

   
   <html>
   <head>
   <title>Matrix Dashboard</title>
   </head>
   <body>
   Hello
   </body>
   </html>
   

   Create electron/tsconfig.json file:

   
   /* electron tsconfig.json */
   {
     "compileOnSave": false,
     "compilerOptions": {
       "baseUrl": "./",
       "outDir": "./dist",
       "sourceMap": true,
       "declaration": false,
       "module": "commonjs",
       "moduleResolution": "node",
       "emitDecoratorMetadata": true,
       "experimentalDecorators": true,
       "target": "es5",
       "typeRoots": ["../node_modules/@types"],
       "lib": ["es2018", "dom"]
     }
   }
   

   Create electron/main.ts file:

   
   import { app, BrowserWindow } from "electron";
   //import { Injectable } from "@angular/core";
   //import { ipcMain, IpcRenderer } from "electron";
   import * as path from "path";
   import * as url from "url";
   
   let win: BrowserWindow;
   
   app.on("ready", createWindow);
   
   app.on("activate", () => {
     if (win === null) {
       createWindow();
     }
   });
   
   /*
   ipcMain.on("getFiles", (event, arg) => {
     const files = fs.readdirSync(__dirname);
     win.webContents.send("getFilesResponse", files);
   });
   */
   
   function createWindow() {
     win = new BrowserWindow({ width: 800, height: 600 });
   
     win.loadURL(
       url.format({
         pathname: path.join(__dirname, `/../../dist/matrix-dashboard/index.html`),
         protocol: "file:",
         slashes: true
       })
     );
   
     //win.webContents.openDevTools();
   
     win.on("closed", () => {
       win = null;
     });
   }
   

   Create electron/package.json file (I added the comment):

   
   {
     "comment": "electron package.json file",
     "name": "matrix-dashboard",
     "version": "0.0.0",
     "main": "electron/dist/main.js",
     "scripts": {
       "ng": "ng",
       "start": "ng serve",
       "build": "ng build",
       "test": "ng test",
       "lint": "ng lint",
       "e2e": "ng e2e",
       "electron": "ng build --base-href ./ && tsc --p . && electron ."
     }
   }
   

   Build and run electron desktop-app:

   
   cd electron/
   npm run electron
   # see desktop app window appear !
   



4. Now to use Bootstrap:
   
   Edit Angular's src/styles.css file to add line:

   @import "../node_modules/bootstrap/dist/css/bootstrap.css"
   

   Edit src/app/app.component.html file to add:

   
   a bootstrap thing:<br />
   <select multiple data-role="tagsinput">
     <option value="Amsterdam">Amsterdam</option>
     <option value="Washington">Washington</option>
     <option value="Sydney">Sydney</option>
     <option value="Beijing">Beijing</option>
     <option value="Cairo">Cairo</option>
   </select>
   

   Build and run Angular web-app:

   
   # cd to main matrix-dashboard/ dir
   ng serve
   # go to http://localhost:4200/
   # see Angular web app running with bootstrap-CSS-influenced "select" in page
   

   
   Build and run electron desktop-app:

   
   cd electron/
   npm run electron
   # see new "select" appear in desktop app window
   



5. Now to use ng-bootstrap:
   
   Let's try a simple example widget: Rating.
   
   Edit src/app/app.component.html file to add:

   
   an ng-bootstrap thing:<br />
   <ngb-rating rate="2"></ngb-rating>
   

   Edit src/app/app.module.ts file to add lines:

   
   import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
   
   // in imports, after BrowserModule:
       NgbModule.forRoot()
   

   Build and run Angular web-app:

   
   # cd to main matrix-dashboard/ dir
   ng serve
   # go to http://localhost:4200/
   # see Angular web app running with new widget in page
   
   # ctrl-C to kill Angular server
   

   Edward Jackson's "Debugging Angular CLI Applications in Visual Studio Code"
   
   Build and run electron desktop-app:

   
   cd electron/
   npm run electron
   # see new widget appear in desktop app window
   



6. Add a new app component that uses ng-bootstrap:
   
   Create src/app/rating-basic.html file containing:

   
   <ngb-rating [(rate)]="currentRate"></ngb-rating>
   <br />
   <pre>Rate: <b>{{currentRate}}</b></pre>
   

   Create src/app/rating-basic.ts file containing:

   
   import {Component} from '@angular/core';
   
   @Component({
     selector: 'ngbd-rating-basic',
     templateUrl: './rating-basic.html'
   })
   export class NgbdRatingBasic {
     currentRate = 8;
   }
   

   Edit src/app/app.component.html file to add:

   
   app component that references an ng-bootstrap thing:<br />
   <ngbd-rating-basic></ngbd-rating-basic>
   

   Edit src/app/app.module.ts file to add lines:

   
   import { NgbdRatingBasic } from './rating-basic';
   
   // in declarations:
       NgbdRatingBasic
   

   Build and run Angular web-app:

   
   # cd to main matrix-dashboard/ dir
   ng serve
   # go to http://localhost:4200/
   # see Angular web app running with new widget in page
   
   # ctrl-C to kill Angular server
   

   Edward Jackson's "Debugging Angular CLI Applications in Visual Studio Code"
   
   Build and run electron desktop-app:

   
   cd electron/
   npm run electron
   # see new widget appear in desktop app window
   

• vscode-angular-html


• vscode-typescript-angular-plugin


• People report problems with vscode-ng-language-service, say it causes a huge performance hit.

7. Add a new app component that is the main window of my application:
   
   Bootstrap - Layout - Overview
   
   
   Ran into a nasty problem involving tables and Angular. I had one big table, with a header row generated in one page/component (mdmainwindow), then next rows generated by N calls to a sub-component (mdrow). But Angular passes the tags <sub-component-name> ... </sub-component-name> through to the browser, and since they are encapsulating each row, they made the browser place the whole row (for rows 2-N) into the first column in the bigger table, not what I wanted. Ended up with an L-shaped table ! I'll have to generate the whole table structure in one page, and then call sub-components to fill the contents of each cell in the table.
   
   HTML looked like:

   <table>
     <tr><td>colheader1</td><td>colheader2</td></tr>
     <mdrow>
       <tr><td>data</td><td>data</td></tr>
     </mdrow>
     <mdrow>
       <tr><td>data</td><td>data</td></tr>
     </mdrow>
     <mdrow>
       <tr><td>data</td><td>data</td></tr>
     </mdrow>
   </table>
   

   
   Fixed it by making mdrow into a TypeScript class, not an Angular class, and never putting <mdrow> in HTML.
   
   Later, someone told me I could have fixed it by invoking ("selecting") MDRow via an attribute on another tag (e.g. <tr mdrow>), instead of via an <mdrow> tag:
   "In @Component you've a 'selector' property. It's pretty much a CSS selector. Normally it's like 'mdrow', but it can be also a class selector ".mdrow" or attribute '[mdrow]'."
   
   Got the code working.
   
   Code is too big to show here. But src/app/mdmainwindow.html file contains:

   
   <table class="table-striped table-bordered table-hover table-sm">
   
   <thead class="thead-light">
   <tr>
   <td> </td>
   <td *ngFor="let colname of appareas[ncurrentapparea].columnnames; index as ncolumn" id="{{colname}}">
     {{colname}}
   </td>
   </tr>
   </thead>
   
   <tr *ngFor="let row of rows; index as nrow" id="{{row.name}}">
     <td>{{row.name}}</td>
     <td *ngFor="let colname of appareas[ncurrentapparea].columnnames; index as ncolumn"
           id="cell{{nrow}}-{{ncolumn}}">
       <mdcell [nrow]="nrow" [ncolumn]="ncolumn"></mdcell>
     </td>
   </tr>
   
   </table>
   

   And src/app/mdmainwindow.ts file contains:

   
   export class MDMainWindow implements OnInit {
     @Input() nrows = 0;
     @Input() ncolumns = 0;
   
     rows: Array<MDRow>;
   
     appareas: Array<MDAppArea>;
     ncurrentapparea = 0;
   
     constructor() {
     }
     ngOnInit() {
       this.rows = new Array();
       for (let r = 0; r < this.nrows; r++) {
         var newrow = new MDRow(r,this.ncolumns);
         this.rows.push(newrow);
       }
   
       this.appareas = new Array();
       var aa = new MDAppArea("Standard",this.ncolumns);
       this.appareas.push(aa);
       aa = new MDAppArea("Custom1",this.ncolumns);
       this.appareas.push(aa);
       aa = new MDAppArea("Custom2",this.ncolumns);
       this.appareas.push(aa);
     }
   }
   

• {{name}} is an "interpolation" to fetch the value of "name".


• [name]=value is a "property binding" to send "value" from parent object to "name" property of the child object.


• (name)=method(value) is an "event binding" that calls the component's "method" when the "name" event occurs.


• [(name1)]=name2 is a "two-way binding" where first value of name2 is copied to name1, then any changes to name1 are copied back to name2.

8. Add database connection:
   
   Angular can do HTTP requests, and SQL databases can provide RESTful APIs, where they accept HTTP requests to do operations.
   
   I wanted to use Node's sql.js module and a local SQLite database, following patrickmoffitt / local-sqlite-example. But Angular is in a browser client with no access to filesystem. And the sql.js module throws errors when added to a TypeScript project.
   
   There used to be an Angular "http" module, but it's been replaced by an "HttpClient" module.
   
   Started looking into client/server components:
   Sunny Sun's "How to map REST API data using Decorator pattern in Angular 6"
   
   GraphQL seems easier than a RESTful connection ?
   
   Client:
   Holger Schmitz's "Build a Simple Web App with Express, Angular, and GraphQL"
   Apollo's "What is Apollo Client and what does it do?"
   Alexandr Selyanov's "How To Use GraphQL with Angular 2"
   Urigo's "GraphQL as a best practice for modern Angular apps?"
   Nikolas Burk's "How to GraphQL - Introduction"
   prisma / graphql-request
   apollographql / apollo-client
   grafoojs / grafoo
   chentsulin / awesome-graphql
   
   Server:
   Mikhail Novikov's "Building a GraphQL Server with Node.js and SQL"
   Sam Hogarth's "Connecting SQLite to GraphQL"
   rexxars / sql-to-graphql
   Jonas Helfer's "Tutorial: How to build a GraphQL server"
   Chimezie Enyinnaya's "Super Simple GraphQL with Node"
   
   
   Then someone said just use IndexedDB, a database inside the browser.
   A complication for me: often there will be two browser profiles, one for daily use and one for web-app testing use. Probably this app will have to "live" in the testing profile.
   MDN's "IndexedDB API
   MDN's "Browser storage limits and eviction criteria
   Wikipedia's "Web storage"
   Works on Firefox, Chrome, Opera.
   Data-size limits not a problem for my app.
   How to backup or copy to another machine ? On Firefox, the DB is under "<profile>/storage/permanent". Or I could create export and import features into my app.
   
   But I see some statements:
   "IndexedDB is a document-oriented database while SQL is relational database ... Avoid using multiple tables in IndexedDB and trying to create joins."
   "SQL is relational database. IndexedDB is an indexed key/value store similar to a document-oriented database."
   
   Wrapper libraries, or DB engines that use IndexdDB for storage:
   SQL-like interface:
   AlaSQL (SQL-like interface)
   Object interface:
   JsStore
   Dexie.js
   NanoSQL
   Lovefield
   
   Firefox uses SQLite to store IndexedDB data, and there's an API directly to SQLite ? Confusing.
   Mozilla's "Performance/Avoid SQLite In Your Next Firefox Feature"
   
   
   Decided to use AlaSQL.
   The AlaSQL Wiki
   
   
   Whoops, better design my database schema first:
   

   Table Name	Row Fields	Example
   projects:	project_id, project_name	Project1
   appareas:	apparea_id, project_id, apparea_name	Standard
   appfunctions:	appfunction_id, project_id, apparea_id, appfunction_name	Login
   activities:	activity_id, project_id, activity_name, role_id, client_id	Learn app
   cells:	cell_id, project_id, appfunction_id, activity_id	Learn app / Login
   tools:	tool_id, tool_name, tool_path_type, tool_path	Burp Suite
   cellpaths:	cellpath_id, cell_id, cellpath_type, path_name, path_type, path, toolid, args	app.com/login.html or docs/doc1.md
   roles:	role_id, role_name	Admin
   clients:	client_id, client_name, devicetype_id, browsertype_id, ostype_id	PFL
   devicetypes:	devicetype_id, devicetype_name	PC
   browsertypes:	browsertype_id, browsertype_name	Firefox
   ostypes:	ostype_id, ostype_name	Windows

   
   Before I changed to AlaSQL, I started to do:
   SQLite Home Page
   Create a new file mdschema.sql:

   CREATE TABLE "projects" (
   	 "project_id" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
   	 "project_name" TEXT(255,0) NOT NULL
   );
   CREATE INDEX "project_name_index" ON projects ("project_name" COLLATE NOCASE ASC);
   INSERT INTO `projects` VALUES
   	(NULL, "Default");
   
   CREATE TABLE "appareas" (
   	 "apparea_id" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
   	 "project_id" INTEGER NOT NULL,
   	FOREIGN KEY(project_id) REFERENCES projects(project_id),
   	 "apparea_name" TEXT(255,0) NOT NULL
   );
   CREATE INDEX "apparea_name_index" ON appareas ("apparea_name" COLLATE NOCASE ASC);
   INSERT INTO `appareas` VALUES
   	(NULL, (SELECT project_id FROM projects WHERE project_name = "Default"), "Standard");
   

   
   

   npm install alasql
   # gave "3 vulnerabilities found"
   

   Create a new file mdsql.ts (only partial code shown):

   import alasql from 'alasql';
   
   ...
   
     alasql("SET AUTOCOMMIT ON");
     alasql("DROP localStorage DATABASE matrixdashboard");
     alasql("CREATE localStorage DATABASE matrixdashboard");
     alasql("ATTACH localStorage DATABASE matrixdashboard AS matrixdashboard");
     alasql("USE matrixdashboard");
   
   ...
   
     var res = alasql('CREATE TABLE projects ( \
                     project_id INT NOT NULL PRIMARY KEY AUTOINCREMENT, \
                     project_name  TEXT(255,0) NOT NULL \
                     )');
   
   ...
   
     var res = alasql('INSERT INTO projects (?,?)',[0,new_project_name]);
   
   ...
   
     var res = alasql("SELECT * FROM projects WHERE project_id=" + project_id);
   
   ...
   
     var res = alasql('CREATE TABLE appareas ( \
                     apparea_id INT NOT NULL PRIMARY KEY AUTOINCREMENT, \
                     project_id INT REFERENCES projects(project_id), \
                     apparea_name  TEXT(255,0) NOT NULL \
                     )');
   

   Every time I start up "ng serve", the very first compile fails with "alasql no default export". Change the source in some tiny way, recompiles, the compile sucseeds, while STILL saying "alasql no default export".
   
   Got things working, creating a database, using it, closing it, opening it. But when I quit out of Firefox and launched it again, the database was gone.
   
   Messed around in FF's storage settings, ended up clearing all storage, and that destroyed everything ! Anything I do in alasql gives "There is no any AlaSQL databases in localStorage" error message. Restarted "ng serve" and FF, tried loads of code combinations, always get that error. Gave up and filed a bug report on GitHub.
   
   An hour later, situation on my machine is fixed. Maybe I forgot to try just starting with a CREATE after it got into this state ? I quit everything, did "npm remove alasql", then "npm install alasql", DROP still gave the error if it was the first operation, but CREATE as first operation worked. And now the database is persistent across quit/relaunch of Firefox, too. I must have gotten the storage into some weird state or something.
   
   Tried building in Electron, and that "alasql no default export" error made the build fail every time. Back to Angular, and tried to eliminate it. Tried all kinds of variations of the import statement in mdsql.ts and the declare/export statements in node_modules/alasql/dist/alasql.d.ts, but no luck.
   
   Then started looking at compiler options, and found something. Added

   "allowSyntheticDefaultImports": true
   

   to src/tsconfig.app.json, and that killed the error, but caused uses of "alasql.databases.*" to fail (can import using either "import alasql from 'alasql';" or "import * as alaSQLSpace from 'alasql';", same behavior with either). I can do without "alasql.databases.*", I think. Holding my breath to see if anything else breaks. Build and run in Electron works.
   
   Started wiring the database further into my app. Reached a point where I was beating my head against a problem for half an hour, finally noticed compile-time errors from "ng serve", and realized it was using an old copy of one of the source files. Restarted it and app worked. Also, if you change a JSON config file, best to kill "ng serve" and restart it.
   
   Built in electron, and app fails with "alasql.min.js: It looks like you are using the browser version of AlaSQL. Please use the alasql.fs.js file instead.".
   
   Tried adding following to electron/package.json file, later (without "../") in angular.json file, but no change:

     "fileReplacements": [
       {
         "replace": "../node_modules/alasql/dist/alasql.min.js",
         "with": "../node_modules/alasql/dist/alasql.fs.js"
       }
     ],
   

   In the app under electron, select View/ToggleDeveloperTools menu item (or ctrl-shift-I) to see console log and errors.
   
   Got the app to run, despite the "alasql.fs.js" error message. And got another message in the console: "This window has node integration enabled by default. In Electron 5.0.0, node integration will be disabled by default. To prepare for this change, set {nodeIntegration: true} in the webPreferences for this window ...". Fixed it; in electron/main.ts, change:

     win = new BrowserWindow({ width: 800, height: 600 });
   

   to:

     win = new BrowserWindow({ width: 800, height: 600, webPreferences: {nodeIntegration: true} });
   

   
   Hey, the database is persistent under Electron ! I was trying to get to that point. I don't see where it's being stored, though; no new files have popped up in the development tree, that I can see. I thought it would not be persistent, because Electron provides a fresh copy of Chromium engine every time it starts ?
   
   Later, found out my database keys are not auto-incrementing. Strange. Looking in Github, found this issue was reported over 3 years ago and still not fixed. Bummer. And still seeing occasional hiccups where AlaSQL gives errors opening the database or a table of it.
   
   Decided to switch from AlaSQL to Dexie.

   npm remove alasql
   

   Later was told "Please remember that any interaction with localstorage is async, so you risk running into problems if you don't handle the async behavour. I recommend the promise notation from Async" So probably I was doing that wrong.


9. Switch to Dexie:
   
   

   npm install dexie --save
   npm install webpack -g
   

   Took a few hours to get things to compile, had to rework various constructors and such. And then started the battle with Promises; I like synchronous code, but for this I have to use asynchronous.
   
   Took a while just to get opening the database to work properly. Then I had to rework the code a couple of times to get Promises working and data going in and out. Then I still ended up with startup not working: NgInit() requests all the data, but then the HTML code executes before the data has arrived, blowing up everything. Consulting with people online, and they're saying I have to learn about more Angular things, resolvers and services and such. Beginning to think I shouldn't use Angular.
   
   Yes, the more they explain "reactive programming" to me, the more I think I want nothing to do with it. I'll have to try a different approach.

1. Starting, with NetBeans and Swing:
   
   Downloaded incubating-netbeans-10.0-bin.zip
   Extracted it to /usr/local/share
   apt install ant
   At CLI, run /usr/local/share/netbeans/bin/netbeans
   
   Followed Saleem Gul and Tomas Pavek's "Introduction to GUI Building":
   Created new project of type Java / Java Application, unchecking "Create Main Class".
   IDE downloaded and installed an extension manager.
   IDE activated Java SE.
   
   Created a quick GUI in Swing and ran it:
   In Projects window, right-click on main project's node and choose New / Other.
   In the New File dialog box, choose the Swing GUI Forms category and the JFrame Form file type.
   Set <projectname>UI as the class name.
   Enter my.<projectname> as the package.
   Files are created and GUI builder opens.
   Drag and drop GUI items, when done select Run / Run Project menu item.
   


2. Get SQLite and JDBC driver:
   
   (There also is "Java DB / Derby", but it seems more complicated than SQLite. Apache Derby)
   
   Followed SQLite Tutorial's "Getting started with SQLite":
   Download Linux binary version of SQLite from https://www.sqlite.org/download.html (it's only about 2 MB)
   Extracted it to /usr/local/share
   cd /usr/local/share/sqlite-tools-linux-x86-3270200
   sqlite3
   type ".quit" to quit
   
   Download SQLite Studio from https://sqlitestudio.pl/index.rvt
   Set Execute permission on the file
   Double-click it to run it
   Installed in /opt/SQLStudio
   Tried it, decided it's better to create database from inside the IDE.
   
   Followed SQLite Tutorial's "SQLite Java: Connect To The SQLite Database Using SQLite JDBC Driver":
   Went to https://bitbucket.org/xerial/sqlite-jdbc/downloads/ and downloaded sqlite-jdbc-3.27.2.1.jar
   Moved JAR file into my project folder
   In NetBean IDE with your project open:
   Select main project node and click on Services tab
   Right-click on Drivers and select New Driver ...
   Specify JAR file
   
   Set up for app to connect through JDBC to database:
   In Services tab, right-click on SQLite driver and select Connect Using ...
   For "JDBC URL" use connection string jdbc:sqlite:matrixdashboard.sqlite3
   Click Finish
   See database appear in next area below Drivers.
   "KDE Wallet" dialog opens up; NetBeans IDE wants to store database login credentials in a secure way (even though there are no credentials).
   Click Cancel two or three times to get rid of dialog.
   


3. Connect app through JDBC to database:
   
   tutorialspoint's "JDBC - Sample, Example Code"
   mkyong's "JDBC Tutorial"
   
   Created table definitions: under Services / JDBC, right-click on Tables and select Create Table ...
   But there seems to be no way to write those definitions into the database, they're just used by the IDE.
   
   In NetBeans IDE, tried right-clicking on main project node and selecting New / Entity classes from database ...
   Interesting code got created, but not quite useful.
   
   Telosys does automatic code-generation from an existing database.
   Laurent Guerin's "Telosys : the concept of lightweight model for code-generation"
   After installing the CLI version, have to edit CFG file to set editor.
   But the documentation is incredibly cryptic, apparently you need a .dbcfg file which I have no idea how to get.
   Gave up on it.
   
   Finally started copying/writing code to connect to database. Took a bit of trial-and-error to get the connect working, key steps were:
   • In NetBeans IDE, right-click on Libraries, select Add JAR/Folder, add sqlite JAR.
   • In code, use driver class name "org.sqlite.JDBC".
   • In code, use connection URL "jdbc:sqlite:matrixdashboard.sqlite3".
   Got the code working, database to table etc.
   
   Some quirks of NetBeans IDE:
   
   
   • Somehow, the main "form" file disappears from the project, so the "Design" button disappears. File still was on disk, so just did an Open File on it, and Design button came back.
   
   
   • In Design mode, can't do GUI design of components that are not top-level ? Found the answer: have to right-click on your main package icon, select New... For modal dialog, select JPanel Form.
   
   
   • But Design mode imposes some restriction: one source file for each UI element (form) you design. So if you have four dialogs which are very similar, figure out a way to design it once, in one class, and use code to hide/reveal/enable/disable elements in the form.
   
   
   • Javadocs: Go to Tools / Java Platforms, for JDK 10 select Javadoc tab. Click on Add URL button, add url "http://docs.oracle.com/javase/10/docs/api/". Now you can right-click on Java classes and see the docs for it.
   
   
   • To generate a Javadocs file for your new classes, go to Run / Generate javadoc (yourprojectname).
   
   
   Put the code into GitHub: BillDietrich / MatrixDashboard

• Zip the project's dist folder into a ZIP archive. (The dist folder might also contain a lib folder, which you would also need to include.)
• Rename ZIP file to JAR file ?
• On CLI: java -jar <jar_name>.jar

# went to https://nodejs.org/en/download/
# downloaded "Linux Binaries (x64)" tar.xz file

# followed instructions at https://github.com/nodejs/help/wiki/Installation
VERSION=v10.15.3
DISTRO=linux-x64
sudo mkdir -p /usr/local/lib/nodejs
sudo mv node-$VERSION-$DISTRO.tar.xz /usr/local/lib/nodejs
cd /usr/local/lib/nodejs
sudo tar -xJvf node-$VERSION-$DISTRO.tar.xz
sudo rm node-$VERSION-$DISTRO.tar.xz

# added following to .bash_profile and .zshrc
# Nodejs
VERSION=v10.15.3
DISTRO=linux-x64
export PATH=/usr/local/lib/nodejs/node-$VERSION-$DISTRO/bin:$PATH

sudo ln -s /usr/local/lib/nodejs/node-$VERSION-$DISTRO/bin/node /usr/bin/node
sudo ln -s /usr/local/lib/nodejs/node-$VERSION-$DISTRO/bin/npm /usr/bin/npm
sudo ln -s /usr/local/lib/nodejs/node-$VERSION-$DISTRO/bin/npx /usr/bin/npx

# tested installation using
cd ~
node -v
npm version
npx -v

https://github.com/mozilla/multi-account-containers and related/derived extensions.

Original project was called "test pilot".

Some resources:

https://discourse.mozilla.org/c/test-pilot/containers (but most recent activity is 8 months ago)

https://wiki.mozilla.org/Security/Contextual_Identity_Project/Containers (but seems outdated/proposal)

https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/contextualIdentities is the missing piece.

Import/export config: issues 1427, 1409, 1420, 1282 in https://github.com/mozilla/multi-account-containers

I want to make an extension that has no UI other than a Settings page.
Started with https://github.com/mdn/webextensions-examples/tree/master/favourite-colour
https://github.com/mdn/webextensions-examples/tree/master/contextual-identities
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/downloads/download

Did:
Copied example code from github.
Changed names etc in code.

sudo bash
npm install --global web-ext
ctrl-D to get out of SU shell
/usr/local/lib/nodejs/node-v10.15.3-linux-x64/bin/web-ext --version

Created repo https://github.com/BillDietrich/ContainersExportImport

In extension project directory:

/usr/local/lib/nodejs/node-v10.15.3-linux-x64/bin/web-ext run --pref privacy.userContext.enabled=true --pref privacy.firstparty.isolate=false --pref privacy.firstparty.isolate.restrict_opener_access=false

In browser running add-on, to see console.log() messages, you don't want web console, you want add-on debugging console. Type about:debugging in the address bar. See your add-on listed. Click the "debug" link for it. A separate window/process will open, showing the output. Click on "console" and enable "persist logs". Then manipulate your add-on. https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Debugging

Got the code working (I think) in debug environment.

To sign the extension for permanent but private (unlisted) use, went to Developer Hub - API Credentials. Logged in wth Firefox account. Clicked on the "Generate new credentials" button to get API keys. Copied the keys.

Then in CLI, in add-on project directory:

/usr/local/lib/nodejs/node-v10.15.3-linux-x64/bin/web-ext sign --api-key=<JWT issuer> --api-secret=<JWT secret>

Got success, it returned a validation ID, and created a .web-extension-id file and a web-ext-artifacts directory. Inside that directory is the .xpi file.

In Firefox, type "about:addons" in address bar (or do alt-T, a) (or do ctrl-shft-a), see add-ons page. Click on "gear" pull-down menu, select "Install add-on from file" menu item. Navigate to web-ext-artifacts directory and select your add-on's .xpi file.

Go to Developer Hub - My Add-ons and log in to see list of your add-ons.

alert() works in debug mode but is a bit broken in "real mode" ? The text and button appear, but no box around them, and they're a bit separated. Supposed to use Notifications, not alert(), in "real mode".

Type "about:profiles" in the address bar to manage profiles or choose a profile. Click on "Launch profile in new browser" button for new/test profile.

To publish to the world:
Tweak descriptions and settings and versions:
https://addons.mozilla.org/en-US/firefox/
log in
https://addons.mozilla.org/en-US/developers/
Click on "Edit Product Page" for your add-on
Click on "Manage Status & Versions"
Publish:
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/Distribution/Submitting_an_add-on
https://addons.mozilla.org/en-US/developers/addons

Was confused about how to change from self-distributed to AMO (public to world). Got this info: "When you submit a new version on the website, the top of the first page in the submission flow is labeled 'Where to Host'. You should see a button or link there that allows you to change the setting to hosted on the site. You can change that setting every time you submit, depending on what you need."

So, make changes and commit and push them.
Do NOT sign the extension to make XPI file.
Add files to a ZIP file: icons, manifest, package, README, LICENSE, source files:

zip archivename.zip file1 file2 ...
zip containersexportimportVERSION.zip background.js icon*.png LICENSE.md manifest.json options.* package.json README.md
zip decentraleyessimpler1.3.zip background.js icon*.png LICENSE.md manifest.json options.* package.json README.md

Login at https://addons.mozilla.org/en-US/firefox/
Go to https://addons.mozilla.org/en-US/developers/addons
Click on link for the add-on
Do NOT click on "upload new version", instead click on "View All".
Click on "Upload a New Version" button.
Click on "Upload a New Version" button.
Under "Where to Host Version", click on "change" link.
Upload ZIP file.
Click on "Sign add-on" button.
Icon did not get picked up, had to edit that setting later.

If there are errors/warnings about the content of your add-on when you try to publish, you can see same list of errors/warnings by running "web-ext lint" locally.

MDN's "Developing extensions for Firefox for Android"

To just quickly try your extension in an Android phone:

1. On computer, create .xpi file.
2. On phone, enable Developer Options.
3. On phone, enable Android USB Debugging.
4. Connect computer to phone via USB cable.
5. On computer CLI, do "adb devices" to see that connection is good.
6. On computer CLI, do "adb push filename.xpi /mnt/sdcard/" to copy file to phone.
7. On phone, launch Firefox for Android browser.
8. In Firefox, browse to file:///mnt/sdcard
9. You may have to Allow access to files by Firefox.
10. See list of filenames.
11. Tap on filename.xpi link.
12. In Firefox, click Allow on warnings.

David Rousset's "Creating One Browser Extension For All Browsers: Edge, Chrome, Firefox, Opera, Brave And Vivaldi"
MDN's "Porting a Google Chrome extension"
MDN's "Chrome incompatibilities"
mozilla / webextension-polyfill

To just quickly try your extension in Chrome:

1. In Chrome, type "chrome://extensions" in address bar.
2. Enable "Developer Mode" (button in upper-right).
3. Click on "Load unpacked", and choose the extension's project folder.
4. See a box for your extension in the Extensions page.
5. If there is a red "Errors" button for your extension, click it.

Useful snippet to allow use of "browser" in Chrome:

window.browser = (function () {
  return window.msBrowser ||
    window.browser ||
    window.chrome;
})();

But, for me, there are too many differences between Firefox and Chrome, I gave up:

• Various manifest.json differences; requires two separate files.
• Permission "browser_specific_settings" not supported in Chrome.
• Chrome doesn't support Promises (maybe use mozilla / webextension-polyfill).

script to generate system status into a file:
- list of browser profiles and extensions and certs
- default browser
- browser home page
- microcode checksum
- BIOS checksum
- /etc/passwd checksum
- /etc/groups checksum
- kernel version
- active network listeners
- VPN status
- IP address
- DNS settings
- MAC address of router (Arpwatch ?)
- dir list of /bin, /usr/bin, ...
- filesystem dirty bits
- list of PCI devices: lspci
- list of SCSI/SATA devices: lsscsi
- dmidecode
- env has changed
- who is logged on right now (w)
- iptables rules
- list of cron jobs
- shell profiles for users
- file explorer extensions
- source editor extensions
- home/.ssh/known_hosts
- /etc/init/*

script to call that script, then diff results with previous results

send alerts to:
- pushbullet (https://unix.stackexchange.com/questions/381821/how-can-i-send-notifications-alerts-using-the-linux-terminal)
- journal (logger -p user.info this is the message")
- email

Started building it.

Then someone pointed me to SysConfCollect (SCC)