refactor(merge,split,json): adopt streaming approach and standardize types, address gradle warnings (#5803)

Co-authored-by: Anthony Stirling <[email protected]>
Co-authored-by: Balázs <[email protected]>

frontend/src/core/components/tools/split/SplitAutomationSettings.tsx

@@ -38,7 +38,7 @@ const SplitAutomationSettings = ({ parameters, onParameterChange, disabled = fal
         label={t("split.steps.chooseMethod", "Choose Method")}
         placeholder={t("split.selectMethod", "Select a split method")}
         value={parameters.method}
-        onChange={(value) => onParameterChange('method', value as (SplitMethod | '') || '')}
+        onChange={(value) => onParameterChange('method', value as SplitMethod | null)}
         data={methodSelectOptions}
         disabled={disabled}
         comboboxProps={{ withinPortal: true, zIndex: Z_INDEX_AUTOMATE_DROPDOWN }}

frontend/src/core/components/tooltips/useSplitSettingsTips.ts

@@ -2,7 +2,7 @@ import { useTranslation } from 'react-i18next';
 import { TooltipContent } from '@app/types/tips';
 import { SPLIT_METHODS, type SplitMethod } from '@app/constants/splitConstants';
 
-export const useSplitSettingsTips = (method: SplitMethod | ''): TooltipContent | null => {
+export const useSplitSettingsTips = (method: SplitMethod | null): TooltipContent | null => {
   const { t } = useTranslation();
 
   if (!method) return null;

frontend/src/core/hooks/tools/split/useSplitOperation.ts

@@ -68,6 +68,7 @@ export const getSplitEndpoint = (parameters: SplitParameters): string => {
   }
 
   switch (parameters.method) {
+    case null:
     case SPLIT_METHODS.BY_PAGES:
       return "/api/v1/general/split-pages";
     case SPLIT_METHODS.BY_SECTIONS:

frontend/src/core/hooks/tools/split/useSplitParameters.ts

@@ -3,7 +3,7 @@ import { BaseParameters } from '@app/types/parameters';
 import { useBaseParameters, BaseParametersHook } from '@app/hooks/tools/shared/useBaseParameters';
 
 export interface SplitParameters extends BaseParameters {
-  method: SplitMethod | '';
+  method: SplitMethod | null;
   pages: string;
   hDiv: string;
   vDiv: string;
@@ -24,7 +24,7 @@ export interface SplitParameters extends BaseParameters {
 export type SplitParametersHook = BaseParametersHook<SplitParameters>;
 
 export const defaultParameters: SplitParameters = {
-  method: '',
+  method: null,
   pages: '',
   hDiv: '2',
   vDiv: '2',
@@ -45,13 +45,8 @@ export const defaultParameters: SplitParameters = {
 export const useSplitParameters = (): SplitParametersHook => {
   return useBaseParameters({
     defaultParameters,
-    endpointName: (params) => {
-      if (!params.method) return ENDPOINTS[SPLIT_METHODS.BY_PAGES];
-      return ENDPOINTS[params.method as SplitMethod];
-    },
+    endpointName: (params) => params.method ? ENDPOINTS[params.method] : ENDPOINTS[SPLIT_METHODS.BY_PAGES],
     validateFn: (params) => {
-      if (!params.method) return false;
-
       switch (params.method) {
         case SPLIT_METHODS.BY_PAGES:
           return params.pages.trim() !== "";

frontend/src/core/tools/Split.tsx

@@ -60,7 +60,7 @@ const Split = (props: BaseToolProps) => {
       {
         title: t("split.steps.chooseMethod", "Choose Method"),
         isCollapsed: !!base.params.parameters.method, // Collapse when method is selected
-        onCollapsedClick: () => base.params.updateParameter('method', ''),
+        onCollapsedClick: () => base.params.updateParameter('method', null),
         tooltip: methodTips,
         content: (
           <CardSelector<SplitMethod, MethodOption>