Add code comments (#437)

* Add code comments

* Set rows per page to 25

* Update handle row change comment

* Revert radix value

src/App.tsx

@@ -12,33 +12,43 @@ import ValueEditor from './ValueEditor';
 import GlobalStyles from './GlobalStyles';
 import { clearFailedAuthRequestsQueue, retryFailedAuthRequests } from './api';
 
-// Initialize Google Analytics
+// Initialize Google Analytics with the given tracking ID
 ReactGA.initialize('G-7XJBCP6P75');
+// Track the initial page load event
 ReactGA.send({ hitType: 'pageview', page: window.location.pathname });
 
 const App: FC = () => {
-  // Need to call forceUpdate if SciGateway tells us to rerender but there's no
-  // forceUpdate in functional components, so this is the hooks equivalent. See
-  // https://reactjs.org/docs/hooks-faq.html#is-there-something-like-forceupdate
+  // Force update mechanism using React's useReducer hook
+  // This is used to trigger a re-render when necessary (e.g. when SciGateway requests it)
+  // There is no direct forceUpdate in functional components, so we increment a state variable instead
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const [_, forceUpdate] = React.useReducer((x) => x + 1, 0);
 
   function handler(e: Event): void {
-    // Attempt to re-render the plugin if we get told to
+    // Handle custom SciGateway events for triggering actions in the app
     const action = (e as CustomEvent).detail;
+
+    // If SciGateway requests a plugin re-render, trigger a re-render
     if ('scigateway:api:plugin_rerender'.match(action)) {
       forceUpdate();
     }
+
+    // If SciGateway invalidates the token, retry failed authentication requests
     if ('scigateway:api:invalidate_token'.match(action)) {
       retryFailedAuthRequests();
     }
+
+    // If SciGateway requests signout, clear the authentication request queue
     if ('scigateway:api:signout'.match(action)) {
       clearFailedAuthRequestsQueue();
     }
   }
 
+  // Attach event listener for SciGateway events when the component mounts
   React.useEffect(() => {
     document.addEventListener('scigateway', handler);
+
+    // Remove event listener when the component unmounts
     return () => {
       document.removeEventListener('scigateway', handler);
     };
@@ -48,20 +58,21 @@ const App: FC = () => {
     <GlobalStyles>
       <Router basename="/fia">
         <Switch>
+          {/* Define application routes */}
           <Route exact path="/">
-            <HomePage />
+            <HomePage /> {/* Renders the HomePage component on the root path */}
           </Route>
           <Route path="/instruments">
-            <Instruments />
+            <Instruments /> {/* Renders the Instruments page */}
           </Route>
           <Route path="/reduction-history/ALL">
-            <JobsAll />
+            <JobsAll /> {/* Displays all reduction jobs */}
           </Route>
           <Route path="/reduction-history/:instrumentName">
-            <JobsGeneral />
+            <JobsGeneral /> {/* Displays reduction jobs filtered by instrument name */}
           </Route>
           <Route path="/value-editor/:jobId">
-            <ValueEditor />
+            <ValueEditor /> {/* Opens the ValueEditor for a specific job */}
           </Route>
         </Switch>
       </Router>

src/ConfigSettings/ConfigSettingsLOQ.tsx

@@ -5,26 +5,32 @@ import React from 'react';
 import { Box, Button } from '@mui/material';
 import { UploadFile, Edit } from '@mui/icons-material';
 
-// Local data
+// Local components
 import ConfigSettingsGeneral from './ConfigSettingsGeneral';
 import FileUploader from './FileUploader';
 
+// API base URL for LOQ-specific requests
 const fiaApiUrl = process.env.REACT_APP_FIA_REST_API_URL;
 const instrument_url = `${fiaApiUrl}/extras/loq`;
+
 const ConfigSettingsLOQ: React.FC = () => {
-  // Insert LOQ specifc buttons into the ConfigSettingsGeneral component
+  // File uploader logic for LOQ
   const { selectedFile, uploadMessage, handleFileSelection, handleFileUpload } = FileUploader(instrument_url);
+
   return (
+    // Render ConfigSettingsGeneral with additional LOQ-specific elements
     <ConfigSettingsGeneral onFileUpload={handleFileUpload}>
+      {/* File upload button */}
       <Box sx={{ display: 'flex', justifyContent: 'space-between', mb: 2 }}>
         <Button component="label" variant="contained" startIcon={<UploadFile />}>
           Upload file...
           <input type="file" multiple hidden onChange={handleFileSelection} />
         </Button>
+        {/* Display upload message if a file is selected */}
         {selectedFile && <Box sx={{ mt: 1, ml: 2 }}>{uploadMessage}</Box>}
       </Box>
 
-      {/* Change script button -- disabled for now */}
+      {/* Change script button (currently disabled) */}
       <Box>
         <Button variant="contained" disabled startIcon={<Edit />}>
           Change script...

src/ConfigSettings/FileUploader.tsx

@@ -1,6 +1,9 @@
-import axios from 'axios';
+// React components
 import { useState } from 'react';
 
+// Axios components
+import axios from 'axios';
+
 // eslint-disable-next-line @typescript-eslint/explicit-function-return-type
 const FileUploader = (instrument_url: string) => {
   const [selectedFile, setSelectedFile] = useState<File | null>(null);

src/GlobalStyles.tsx

@@ -4,15 +4,19 @@ import React from 'react';
 // Material UI components
 import { ThemeProvider, StyledEngineProvider, Theme, createTheme } from '@mui/material/styles';
 
+// Initialize a default theme
 let theme: Theme = createTheme();
 
+// Listen for theme changes from SciGateway and update the theme dynamically
 document.addEventListener('scigateway', (e) => {
   const action = (e as CustomEvent).detail;
+  // If the event contains theme options, update the theme
   if (action.type === 'scigateway:api:send_themeoptions' && action.payload && action.payload.theme) {
     theme = action.payload.theme;
   }
 });
 
+// GlobalStyles component wraps the app in a theme provider
 class GlobalStyles extends React.Component<{ children: React.ReactNode }> {
   public constructor(props: { children: React.ReactNode }) {
     super(props);
@@ -21,6 +25,7 @@ class GlobalStyles extends React.Component<{ children: React.ReactNode }> {
   public render(): React.ReactElement {
     return (
       <StyledEngineProvider injectFirst>
+        {/* Apply the theme to all children components */}
         <ThemeProvider theme={theme}>{this.props.children}</ThemeProvider>
       </StyledEngineProvider>
     );

src/Instruments.tsx

@@ -13,9 +13,12 @@ import { instruments } from './InstrumentData';
 
 const Instruments: React.FC = () => {
   const theme = useTheme();
+  // State for tracking expanded instruments
   const [expandedIds, setExpandedIds] = React.useState<number[]>([]);
+  // State for tracking favorite instruments
   const [favoriteIds, setFavoriteIds] = React.useState<number[]>([]);
 
+  // Toggle expansion state of an instrument
   const handleToggleExpand = (id: number, event?: React.MouseEvent): void => {
     if (event) {
       event.stopPropagation();
@@ -27,6 +30,7 @@ const Instruments: React.FC = () => {
     );
   };
 
+  // Toggle favorite state of an instrument
   const handleToggleFavorite = (id: number, event: React.MouseEvent): void => {
     event.stopPropagation();
     setFavoriteIds((prevFavoriteIds) =>
@@ -36,6 +40,7 @@ const Instruments: React.FC = () => {
     );
   };
 
+  // Sort instruments based on favorite status
   const sortedInstruments = [...instruments].sort((a, b) => {
     if (favoriteIds.includes(a.id) && !favoriteIds.includes(b.id)) {
       return -1;
@@ -48,6 +53,7 @@ const Instruments: React.FC = () => {
 
   return (
     <>
+      {/* Page title */}
       <Typography variant="h3" component="h1" style={{ color: theme.palette.text.primary, padding: '20px' }}>
         ISIS instruments
       </Typography>
@@ -70,6 +76,7 @@ const Instruments: React.FC = () => {
             >
               <Box display="flex" alignItems="center" justifyContent="space-between">
                 <Box display="flex" alignItems="center">
+                  {/* Expand button */}
                   <IconButton
                     aria-expanded={expandedIds.includes(instrument.id)}
                     aria-label="show more"
@@ -80,6 +87,7 @@ const Instruments: React.FC = () => {
                     />
                   </IconButton>
                   <Box sx={{ marginLeft: 2 }}>
+                    {/* Instrument name and type */}
                     <Typography
                       variant="h6"
                       component="h1"
@@ -97,6 +105,7 @@ const Instruments: React.FC = () => {
                     </Typography>
                   </Box>
                 </Box>
+                {/* Favorite button */}
                 <IconButton
                   aria-label="add to favorites"
                   onClick={(event) => handleToggleFavorite(instrument.id, event)}
@@ -111,6 +120,7 @@ const Instruments: React.FC = () => {
               <Collapse in={expandedIds.includes(instrument.id)} timeout="auto" unmountOnExit>
                 <Box marginTop={2}>
                   <Box display="flex" justifyContent="space-between" alignItems="flex-start">
+                    {/* Instrument description */}
                     <Typography
                       variant="body2"
                       paragraph
@@ -119,6 +129,7 @@ const Instruments: React.FC = () => {
                       {instrument.description}
                     </Typography>
                     <Box sx={{ flex: 1, marginLeft: 4 }}>
+                      {/* List of associated scientists */}
                       <Typography variant="body2" sx={{ fontWeight: 'bold', color: theme.palette.text.primary }}>
                         Scientists:
                       </Typography>
@@ -131,10 +142,12 @@ const Instruments: React.FC = () => {
                       </List>
                     </Box>
                   </Box>
+                  {/* Link to more information */}
                   <Link href={instrument.infoPage} target="_blank" rel="noopener" underline="always">
                     {instrument.infoPage}
                   </Link>
                   <Box marginTop={2}>
+                    {/* Button to view reduction history */}
                     <Button
                       variant="contained"
                       component={RouterLink}

src/Jobs/JobsAll.tsx

@@ -6,22 +6,35 @@ import { useHistory, useParams, Link } from 'react-router-dom';
 import { useTheme } from '@mui/material/styles';
 import { TableCell } from '@mui/material';
 
-// Local data
+// Local data and utilities
 import JobsBase, { useFetchJobs, useFetchTotalCount, Job, headerStyles } from './JobsBase';
 
 const JobsAll: React.FC = () => {
+  // Extract instrument name from URL parameters
   const { instrumentName } = useParams<{ instrumentName: string }>();
+
+  // Retrieve the current theme for styling
   const theme = useTheme();
+
+  // Hook for handling navigation within the app
   const history = useHistory();
-  const [jobs, setJobs] = useState<Job[]>([]);
-  const [totalRows, setTotalRows] = useState(0);
-  const [currentPage, setCurrentPage] = useState(0);
-  const [rowsPerPage, setRowsPerPage] = useState(25);
-  const [orderDirection, setOrderDirection] = useState<'asc' | 'desc'>('desc');
-  const [selectedInstrument, setSelectedInstrument] = useState(instrumentName || 'ALL');
-  const [orderBy, setOrderBy] = useState<string>('run_start');
+
+  // State variables for job data and table pagination
+  const [jobs, setJobs] = useState<Job[]>([]); // Stores fetched job data
+  const [totalRows, setTotalRows] = useState(0); // Stores total number of job entries
+  const [currentPage, setCurrentPage] = useState(0); // Current page in pagination
+  const [rowsPerPage, setRowsPerPage] = useState(25); // Number of rows displayed per page
+  const [orderDirection, setOrderDirection] = useState<'asc' | 'desc'>('desc'); // Sorting order (ascending/descending)
+  const [selectedInstrument, setSelectedInstrument] = useState(instrumentName || 'ALL'); // Selected instrument filter
+  const [orderBy, setOrderBy] = useState<string>('run_start'); // Column to sort by
+
+  // Calculate the offset for API query based on current page
   const offset = currentPage * rowsPerPage;
+
+  // Construct API query string with pagination and sorting parameters
   const query = `limit=${rowsPerPage}&offset=${offset}&order_by=${orderBy}&order_direction=${orderDirection}&include_run=true`;
+
+  // Fetch job data and total count using custom hooks
   const fetchJobs = useFetchJobs(`/jobs`, query, setJobs);
   const fetchTotalCount = useFetchTotalCount(`/jobs/count`, setTotalRows);
 
@@ -32,25 +45,27 @@ const JobsAll: React.FC = () => {
         const newInstrument = event.target.value;
         setSelectedInstrument(newInstrument);
         setCurrentPage(0);
-        history.push(`/reduction-history/${newInstrument}`);
+        history.push(`/reduction-history/${newInstrument}`); // Navigate to selected instrument's history
       }}
       jobs={jobs}
       totalRows={totalRows}
       currentPage={currentPage}
       rowsPerPage={rowsPerPage}
-      handleChangePage={(_, newPage) => setCurrentPage(newPage)}
-      handleChangeRowsPerPage={(e) => setRowsPerPage(parseInt(e.target.value, 10))}
+      handleChangePage={(_, newPage) => setCurrentPage(newPage)} // Update page number
+      handleChangeRowsPerPage={(e) => setRowsPerPage(parseInt(e.target.value, 10))} // Update rows per page based on what the user has selected (10 is the radix, do not confuse for number of rows)
       handleSort={(property) => {
         const isAsc = orderBy === property && orderDirection === 'asc';
-        setOrderDirection(isAsc ? 'desc' : 'asc');
+        setOrderDirection(isAsc ? 'desc' : 'asc'); // Toggle sorting order
         setOrderBy(property);
-        setCurrentPage(0);
+        setCurrentPage(0); // Reset to first page after sorting
       }}
       orderBy={orderBy}
       orderDirection={orderDirection}
       fetchJobs={fetchJobs}
       fetchTotalCount={fetchTotalCount}
+      // Custom table header for instrument column
       customHeaders={<TableCell sx={{ width: '10%', ...headerStyles(theme) }}>Instrument</TableCell>}
+      // Custom rendering of job row cells for instrument name with a clickable link
       customRowCells={(job: Job) => (
         <TableCell sx={{ width: '10%' }}>
           {job.run?.instrument_name ? (
@@ -60,17 +75,17 @@ const JobsAll: React.FC = () => {
                 color: theme.palette.mode === 'dark' ? '#86b4ff' : theme.palette.primary.main,
                 textDecoration: 'none',
               }}
-              onMouseEnter={(e) => (e.currentTarget.style.textDecoration = 'underline')}
-              onMouseLeave={(e) => (e.currentTarget.style.textDecoration = 'none')}
+              onMouseEnter={(e) => (e.currentTarget.style.textDecoration = 'underline')} // Underline on hover
+              onMouseLeave={(e) => (e.currentTarget.style.textDecoration = 'none')} // Remove underline on hover out
             >
               {job.run.instrument_name}
             </Link>
           ) : (
-            'Unknown'
+            'Unknown' // Display 'Unknown' if no instrument name exists
           )}
         </TableCell>
       )}
-      maxHeight={650}
+      maxHeight={650} // Limit table height
     />
   );
 };