fts5 search: better error handling and some better index loading and unloading

2 files changed, 90 insertions, 31 deletions

diff --git a/themes/new_theme/layouts/partials/ranklist_fts5.html b/themes/new_theme/layouts/partials/ranklist_fts5.html
index 5677c40..69c0f39 100644
--- a/themes/new_theme/layouts/partials/ranklist_fts5.html
+++ b/themes/new_theme/layouts/partials/ranklist_fts5.html
@@ -41,53 +41,112 @@
 		return html;
 	}
 
+	function submitQuery( ) {
+		try {
+			if( window.location.pathname.includes( "/search/") ) {
+				var q = $( "#query" ).val( );
+				executeQuery( q );
+				return false;
+			} else {
+				return true;
+			}
+		} catch( e ) {
+			alert( e );
+		}
+	}
+	
+	var index_loaded = false;
+	var SQL;
+	var db;
+	var stmt;
+	
+	function loadIndex( success, fail ) {
+		if( !index_loaded ) {
+			const xhr = new XMLHttpRequest( );
+			xhr.open( 'GET', '/index/posts.db', true );
+			xhr.responseType = 'arraybuffer';
+			xhr.onload = e => {
+				if( ( xhr.status == 0 ) || ( xhr.status == 200 ) ) {
+					const uInt8Array = new Uint8Array( xhr.response );
+					requirejs(["/js/sql-wasm.js"], function(initSqlJs) {
+
+						SQL = initSqlJs( {
+						  locateFile: file => `/js/${file}`
+						} );
+
+						initSqlJs( ).then( function( SQL ) {
+							db = new SQL.Database(uInt8Array);
+							stmt = db.prepare( "select uri as docid,title,snippet(posts, 2, '<b>', '</b>', '...', 50) as abstract from posts where posts MATCH @query ORDER BY bm25(posts)" );
+							
+							index_loaded = true;
+							
+							success( );
+						} );
+					} );
+				} else {
+					const uInt8Array = new Uint8Array( xhr.response );
+					const decoder = new TextDecoder( );
+					const msg = decoder.decode( uInt8Array );
+					fail( xhr.status, xhr.statusText, msg );
+				}
+			}
+			xhr.send( );
+		} else {
+			success( );
+		}
+	}
+	
 	function executeQuery( query ) {		
 		$( "#query" ).LoadingOverlay( "show" );
 		
-		const xhr = new XMLHttpRequest();
-		xhr.open('GET', '/index/posts.db', true);
-		xhr.responseType = 'arraybuffer';
-		xhr.onload = e => {
-			const uInt8Array = new Uint8Array( xhr.response );
-			requirejs(["/js/sql-wasm.js"], function(initSqlJs) {
-
-				const SQL = initSqlJs( {
-				  locateFile: file => `/js/${file}`
-				} );
+		loadIndex(
+		function( ) {
+			stmt.bind( {'@query' : query} );
 
-				initSqlJs( ).then( function( SQL ) {
-					var db = new SQL.Database(uInt8Array);
-					const stmt = db.prepare( "select uri as docid,title,snippet(posts, 2, '<b>', '</b>', '...', 50) as abstract from posts where posts MATCH @query ORDER BY bm25(posts)" );
-					stmt.bind( {'@query' : query} );
+			var html;
+			try {
+				var results = [];
+				while( stmt.step( ) ) {
+					var row = stmt.getAsObject( );
+					results.push( row );
+				}
 
-					var results = [];
-					while( stmt.step( ) ) {
-						var row = stmt.getAsObject( );
-						results.push( row );
-					}
-					stmt.free( );
-					db.close( );
+				html = draw_ranklist( query, results );
+			} catch( e ) {
+				html = "<pre><font color='red'>There was an error executing the query '" + query + "', reason: " + e + "</font></pre>\n";
+			}
+			
+			$( '#ranklist' ).html( html );
 
-					var html = draw_ranklist( query, results );
-					
-					$( '#ranklist' ).html( html );
-										
-					$( "#query" ).LoadingOverlay( "hide" );
-				} );
-			} );
+			$( "#query" ).LoadingOverlay( "hide" );
+		},
+		function( status, statusText, msg ) {
+			var html = "<pre><font color='red'>There was an error executing the query '" + query + "', reason: " + status + " " + statusText + "</font></pre>\n";
+			$( '#ranklist' ).html( html );
+			$( "#query" ).LoadingOverlay( "hide" );
 		}
-		xhr.send( );
+		);
 	}
 
 	$( window ).load( function( ) {
 		var paramsString = window.location.search;
 		var searchParams = new URLSearchParams( paramsString );
 		if( searchParams.has( "q" ) ) {
-			executeQuery( searchParams.get( "q" ) );
+			var q = searchParams.get( "q" )
+			$( "#query" ).val( q );
+			executeQuery( q );
 		} else {
 			// TODO: come up with something here
 		}	// Show full page LoadingOverlay
 	} );
+	
+	$( window ).unload( function( ) {
+		if( index_loaded ) {
+			stmt.free( );
+			db.close( );
+			index_loaded = false;
+		}
+	} );
 </script>
 <div id="ranklist">
 </div>
diff --git a/themes/new_theme/layouts/partials/widgets/fts5_search.html b/themes/new_theme/layouts/partials/widgets/fts5_search.html
index 5da7a2a..7f58e32 100644
--- a/themes/new_theme/layouts/partials/widgets/fts5_search.html
+++ b/themes/new_theme/layouts/partials/widgets/fts5_search.html
@@ -1,6 +1,6 @@
 <h4 class="widget__title">Search</h4>
 <div class="widget-search widget">
-	<form class="widget-search__form" role="search" method="get" action="/search/">
+	<form id="search_form" class="widget-search__form" role="search" method="get" action="/search/" onsubmit="return submitQuery( );">
 		<label>
 			<input class="widget-search__field" type="search" autocomplete="off" placeholder="{{ T "search_placeholder" }}" value="" id="query" name="q" aria-label="{{ T "search_placeholder" }}">
 		</label>