enable client side caching for plot requests

Doesn't work perfectly yet, because the height/width sometimes changes
by one or two pixels.

pdb-ui/src/main/resources/application.properties

@@ -4,4 +4,6 @@ db.base=${base.dir}/db
 path.tmp=${base.dir}/tmp
 path.output=${base.dir}/out
 
+cache.images.duration.seconds=3600
+
 logging.config=classpath:log4j2.xml

pdb-ui/src/main/resources/resources/js/ui.js

@@ -908,7 +908,10 @@ function sendPlotRequest(query){
 	};
 	
 	data.searchBar.imagelink = '';
-	postJson("plots", request, success, error);
+	const requestParam = {
+		'request': JSON.stringify(request)
+	};
+	getJson("plots", requestParam, success, error)
 }
 
 function updateImageLink(query) {
@@ -1002,7 +1005,10 @@ function createDashboardItem(originalQuery, field, imageHeight, imageWidth)
 			data.dashboard.progress.value++;
 			createDashboardItem(originalQuery, field, imageHeight, imageWidth);
 		};
-		postJson("plots", request, success, error);
+		var requestParam = {
+			request: JSON.stringify(request)
+		};
+		getJson("plots", requestParam, success, error)
 	}
 }
 
@@ -1045,7 +1051,8 @@ function getJson(url, requestData, successCallback, errorCallback) {
 			type: "GET",
 			url: url,
 			data: requestData,
-			contentType: 'application/json'
+			contentType: 'application/json',
+			cache:true
 		})
 		.done(successCallback)
 		.fail(errorCallback);