Enable back button functionality, clear url on load

gui/src/app/SPAnalysis/SPAnalysisContextProvider.tsx

@@ -2,7 +2,8 @@ import { initialDataModel, SPAnalysisDataModel } from "./SPAnalysisDataModel"
 import { createContext, FunctionComponent, PropsWithChildren, useEffect, useReducer } from "react"
 import { SPAnalysisReducer, SPAnalysisReducerAction, SPAnalysisReducerType } from "./SPAnalysisReducer"
 import { deserializeAnalysisFromLocalStorage, serializeAnalysisToLocalStorage } from "./SPAnalysisSerialization"
-import { fetchRemoteAnalysis, queryStringHasParameters, useQueryParams } from "./SPAnalysisQueryLoading"
+import { fetchRemoteAnalysis, queryStringHasParameters, fromQueryParams } from "./SPAnalysisQueryLoading"
+import { useSearchParams } from "react-router-dom"
 
 type SPAnalysisContextType = {
     data: SPAnalysisDataModel
@@ -19,10 +20,9 @@ export const SPAnalysisContext = createContext<SPAnalysisContextType>({
 
 
 const SPAnalysisContextProvider: FunctionComponent<PropsWithChildren<SPAnalysisContextProviderProps>> = ({ children }) => {
+    const [data, update] = useReducer<SPAnalysisReducerType>(SPAnalysisReducer, initialDataModel)
 
-    const { queries, clearSearchParams } = useQueryParams();
-
-    const [data, update] = useReducer<SPAnalysisReducerType>(SPAnalysisReducer(clearSearchParams), initialDataModel)
+    const [searchParams, setSearchParams] = useSearchParams();
 
     useEffect(() => {
         // as user reloads the page or closes the tab, save state to local storage
@@ -38,11 +38,15 @@ const SPAnalysisContextProvider: FunctionComponent<PropsWithChildren<SPAnalysisC
     }, [data])
 
     useEffect(() => {
-        if (data != initialDataModel) return;
-
+        const queries = fromQueryParams(searchParams)
         if (queryStringHasParameters(queries)) {
             fetchRemoteAnalysis(queries).then((data) => {
-                update({ type: 'loadInitialData', state: data })
+                update({ type: 'loadInitialData', state: data });
+
+                // set title so that history is better preserved in the browser
+                document.title = "Stan Playground - " + data.meta.title;
+                // clear search parameters now that load is complete
+                setSearchParams(new URLSearchParams());
             })
         } else {
             // load the saved state on first load
@@ -51,8 +55,10 @@ const SPAnalysisContextProvider: FunctionComponent<PropsWithChildren<SPAnalysisC
             const parsedData = deserializeAnalysisFromLocalStorage(savedState)
             update({ type: 'loadInitialData', state: parsedData })
         }
-
-    }, [data, queries])
+        // once we have loaded some data, we don't need the localStorage again
+        // and it will be overwritten by the above event listener on close
+        localStorage.removeItem('stan-playground-saved-state')
+    }, [searchParams, setSearchParams])
 
     return (
         <SPAnalysisContext.Provider value={{ data, update }}>

gui/src/app/SPAnalysis/SPAnalysisQueryLoading.ts

@@ -1,6 +1,4 @@
-import { useSearchParams } from "react-router-dom";
 import { SPAnalysisDataModel, initialDataModel, persistStateToEphemera } from "./SPAnalysisDataModel";
-import { useCallback } from "react";
 
 
 enum QueryParamKeys {
@@ -19,16 +17,7 @@ type QueryParams = {
     [key in QueryParamKeys]: string | null
 }
 
-export const useQueryParams = () => {
-    const [searchParams, setSearchParams] = useSearchParams();
-
-    const clearSearchParams = useCallback(() => {
-        // whenever the data state is 'dirty', we want to
-        // clear the URL bar as to indiciate that the viewed content is
-        // no longer what the link would point to
-        if (searchParams.size !== 0)
-            setSearchParams(new URLSearchParams())
-    }, [searchParams, setSearchParams]);
+export const fromQueryParams = (searchParams: URLSearchParams) => {
 
     for (const key of searchParams.keys()) {
         // warn on unknown keys
@@ -49,7 +38,7 @@ export const useQueryParams = () => {
         seed: searchParams.get(QueryParamKeys.SOSeed),
     }
 
-    return { queries, clearSearchParams }
+    return queries;
 }
 
 export const queryStringHasParameters = (query: QueryParams) => {

gui/src/app/SPAnalysis/SPAnalysisReducer.ts

@@ -34,14 +34,7 @@ export type SPAnalysisReducerAction = {
     type: 'clear'
 }
 
-export const SPAnalysisReducer = (onDirty: () => void) => (s: SPAnalysisDataModel, a: SPAnalysisReducerAction) => {
-    if (a.type !== "loadInitialData") {
-        // TextEditor seems to trigger occasional spurious edits where nothing changes
-        if (a.type !== "editFile" || s[a.filename] != a.content) {
-            onDirty();
-        }
-    }
-
+export const SPAnalysisReducer = (s: SPAnalysisDataModel, a: SPAnalysisReducerAction) => {
     switch (a.type) {
         case "loadStanie": {
             const dataFileContent = JSON.stringify(a.stanie.data, null, 2);
@@ -123,4 +116,4 @@ const loadFromProjectFiles = (data: SPAnalysisDataModel, files: Partial<FieldsCo
     newData = fileKeys.reduce((currData, currField) => loadFileFromString(currData, currField, files[currField] ?? ''), newData)
     newData = persistStateToEphemera(newData)
     return newData
-}
+}