added cache for task and wiki page markdown editor, reverted previous attempt

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

frontend/src/Components/MarkdownEditor.svelte

@@ -6,9 +6,9 @@
     let {
         editable = true,
         onclick  = evt => {},
-        onRender = src => {},
         onSet    = newVal => {return true;},
         simple   = false,
+        store_id = null,
         type     = 'div',
         value    = $bindable({source:null,rendered:null})
     } = $props();
@@ -16,6 +16,7 @@
     let editing   = $state(false);
     let editValue = $state({source:value.source,rendered:value.rendered});
     let start     = 0;
+    let stored_source = $state(store_id ? localStorage.getItem(store_id) : null);
     let timer     = null;
 
     async function applyEdit(){
@@ -28,6 +29,7 @@
     }
 
     function doSave(){
+        if (store_id) localStorage.removeItem(store_id);
         if (simple){
             onSet(editValue.source);
         } else applyEdit();
@@ -51,7 +53,7 @@
             body       : editValue.source
         });
         editValue.rendered = await resp.text();
-        onRender(editValue.source);
+        if (store_id) localStorage.setItem(store_id,editValue.source);
     }
 
     function typed(ev){
@@ -102,13 +104,37 @@
         measured(evt, evt.timeStamp - start);
     }
 
+    function restore(ev){
+        editValue.source = stored_source;
+        stored_source = null;
+        render();
+    }
+
     activeField.subscribe((val) => resetEdit());
     if (simple) startEdit();
 </script>
 
+<style>
+    .markdown{
+        position: relative;
+    }
+    #restore_markdown{
+        position: absolute;
+        right: 50%;
+        top: -10px;
+        background: orange;
+        color: black;
+        padding: 5px;
+        border-radius: 5px;
+    }
+</style>
+
 <div class="markdown {editing?'editing':''}">
 {#if editing}
     <span class="hint">{@html t('markdown_supported')}</span>
+    {#if stored_source}
+    <span id="restore_markdown" onclick={restore} class="hint">{t('unsaved_content')}</span>
+    {/if}
     <textarea bind:value={editValue.source} onkeyup={typed} autofocus={!simple}></textarea>
     <div class="preview">{@html target(editValue.rendered)}</div>
     {#if !simple}