fix(plugin-data-viewer): CB-1305 fetch cancellation

webapp/packages/core-connections/src/ConnectionExecutionContext/ConnectionExecutionContext.ts

@@ -6,7 +6,7 @@
  * you may not use this file except in compliance with the License.
  */
 
-import { makeObservable, observable } from 'mobx';
+import { computed, makeObservable, observable } from 'mobx';
 
 import type { ITask, TaskScheduler } from '@cloudbeaver/core-executor';
 
@@ -37,6 +37,9 @@ export class ConnectionExecutionContext implements IConnectionExecutionContext {
     this.currentTask = null;
     makeObservable<this, 'currentTask'>(this, {
       currentTask: observable.ref,
+      context: computed,
+      executing: computed,
+      cancellable: computed,
     });
   }
 

webapp/packages/core-executor/src/TaskScheduler/Task.ts

@@ -6,7 +6,7 @@
  * you may not use this file except in compliance with the License.
  */
 
-import { makeObservable, observable } from 'mobx';
+import { computed, makeObservable, observable } from 'mobx';
 
 import type { ITask } from './ITask';
 
@@ -15,7 +15,11 @@ export class Task<TValue> implements ITask<TValue> {
   executing: boolean;
 
   get cancellable(): boolean {
-    return !this.cancelled && (!this.executing || !!this.externalCancel);
+    if (this.cancelled) {
+      return false;
+    }
+
+    return !this.executing || this.externalCancel !== undefined;
   }
 
   private resolve!: (value: TValue) => void;
@@ -38,6 +42,7 @@ export class Task<TValue> implements ITask<TValue> {
     this.executing = false;
 
     makeObservable(this, {
+      cancellable: computed,
       cancelled: observable,
       executing: observable,
     });
@@ -107,6 +112,10 @@ export class Task<TValue> implements ITask<TValue> {
   }
 
   cancel(): Promise<void> | void {
+    if (this.cancelled) {
+      return;
+    }
+
     this.cancelled = true;
 
     if (!this.executing) {

webapp/packages/plugin-data-viewer/src/ContainerDataSource.ts

@@ -6,6 +6,8 @@
  * you may not use this file except in compliance with the License.
  */
 
+import { computed, makeObservable, observable } from 'mobx';
+
 import type { ConnectionExecutionContextService, IConnectionExecutionContext, IConnectionExecutionContextInfo } from '@cloudbeaver/core-connections';
 import type { NotificationService } from '@cloudbeaver/core-events';
 import type { ITask } from '@cloudbeaver/core-executor';
@@ -38,6 +40,11 @@ export class ContainerDataSource extends DatabaseDataSource<IDataContainerOption
 
     this.currentTask = null;
     this.executionContext = null;
+
+    makeObservable(this, {
+      currentTask: observable.ref,
+      canCancel: computed,
+    });
   }
 
   isDisabled(resultIndex: number): boolean {