[Feature] Expressions example plugin (#1438)

* feat(Expressions): Initial demo plugin

Signed-off-by: Ashwin Pc <ashwinpc@amazon.com>

* feat(Expressions): Adds handlers tab

Signed-off-by: Ashwin Pc <ashwinpc@amazon.com>

* feat(Expressions): Adds playground tab

Signed-off-by: Ashwin Pc <ashwinpc@amazon.com>

* chore: Better expression playground messaging

Signed-off-by: Ashwin Pc <ashwinpc@amazon.com>

* feat(Expressions): Adds expression explorer

Signed-off-by: Ashwin Pc <ashwinpc@amazon.com>

* feat(Expressions): A better explorer

Signed-off-by: Ashwin Pc <ashwinpc@amazon.com>

* fix(Expressions): Fix basic demo abort error

Signed-off-by: Ashwin Pc <ashwinpc@amazon.com>

* Updates readme and fixes rendering visualizations

Signed-off-by: Ashwin Pc <ashwinpc@amazon.com>

examples/expressions_example/.eslintrc.js

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+module.exports = {
+  root: true,
+  extends: ['@elastic/eslint-config-kibana', 'plugin:@elastic/eui/recommended'],
+  rules: {
+    '@osd/eslint/require-license-header': 'off',
+  },
+};

examples/expressions_example/.i18nrc.json

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+{
+  "prefix": "expressionsExample",
+  "paths": {
+    "expressionsExample": "."
+  },
+  "translations": ["translations/ja-JP.json"]
+}

examples/expressions_example/README.md

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+# expressions_example
+
+An OpenSearch Dashboards example plugin to demonstrate the expressions plugin
+
+---
+
+## Development
+
+See the [OpenSearch Dashboards contributing
+guide](https://github.com/opensearch-project/OpenSearch-Dashboards/blob/master/CONTRIBUTING.md) for instructions
+setting up your development environment.

examples/expressions_example/common/expression_functions/action/index.ts

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export * from './quick_form_fn';
+export * from './quick_form_renderer';

examples/expressions_example/common/expression_functions/action/quick_form_fn.ts

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { i18n } from '@osd/i18n';
+import {
+  ExpressionFunctionDefinition,
+  Render,
+} from '../../../../../src/plugins/expressions/public';
+import { QuickFormRenderValue } from './quick_form_renderer';
+
+type Arguments = QuickFormRenderValue;
+
+export const quickFormFn = (): ExpressionFunctionDefinition<
+  'quick-form',
+  unknown,
+  Arguments,
+  Render<QuickFormRenderValue>
+> => ({
+  name: 'quick-form',
+  type: 'render',
+  help: i18n.translate('expressionsExample.function.avatar.help', {
+    defaultMessage: 'Render a simple form that sends the value back as an event on click',
+  }),
+  args: {
+    label: {
+      types: ['string'],
+      help: i18n.translate('expressionsExample.function.form.args.label.help', {
+        defaultMessage: 'Form label',
+      }),
+      default: i18n.translate('expressionsExample.function.form.args.label.default', {
+        defaultMessage: 'Input',
+      }),
+    },
+    buttonLabel: {
+      types: ['string'],
+      help: i18n.translate('expressionsExample.function.form.args.buttonLabel.help', {
+        defaultMessage: 'Button label',
+      }),
+      default: i18n.translate('expressionsExample.function.form.args.buttonLabel.default', {
+        defaultMessage: 'Submit',
+      }),
+    },
+  },
+  fn: (input, args) => {
+    return {
+      type: 'render',
+      as: 'quick-form-renderer',
+      value: { ...args },
+    };
+  },
+});

examples/expressions_example/common/expression_functions/action/quick_form_renderer.tsx

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import React, { useCallback, useState } from 'react';
+import { EuiForm, EuiFormRow, EuiButton, EuiFieldText } from '@elastic/eui';
+import { i18n } from '@osd/i18n';
+import { render, unmountComponentAtNode } from 'react-dom';
+import { ExpressionRenderDefinition } from '../../../../../src/plugins/expressions/public';
+
+export interface QuickFormRenderValue {
+  label: string;
+  buttonLabel: string;
+}
+
+export const quickFormRenderer: ExpressionRenderDefinition<QuickFormRenderValue> = {
+  name: 'quick-form-renderer',
+  displayName: i18n.translate('expressionsExample.form.render.help', {
+    defaultMessage: 'Render a simple input form',
+  }),
+  reuseDomNode: true,
+  render: (domNode, config, handlers) => {
+    handlers.onDestroy(() => {
+      unmountComponentAtNode(domNode);
+    });
+
+    render(
+      <QuickForm
+        {...config}
+        onSubmit={(value) =>
+          handlers.event({
+            data: value,
+          })
+        }
+      />,
+      domNode,
+      handlers.done
+    );
+  },
+};
+
+interface QuickFormProps extends QuickFormRenderValue {
+  onSubmit: Function;
+}
+
+const QuickForm = ({ onSubmit, buttonLabel, label }: QuickFormProps) => {
+  const [value, setValue] = useState('');
+  const handleClick = useCallback(() => {
+    onSubmit(value);
+  }, [onSubmit, value]);
+
+  return (
+    <EuiForm>
+      <EuiFormRow label={label}>
+        <EuiFieldText value={value} onChange={(e) => setValue(e.target.value)} />
+      </EuiFormRow>
+      <EuiButton onClick={handleClick}>{buttonLabel}</EuiButton>
+    </EuiForm>
+  );
+};

examples/expressions_example/common/expression_functions/basic/index.ts

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export * from './sleep';
+export * from './square';

examples/expressions_example/common/expression_functions/basic/sleep.ts

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { i18n } from '@osd/i18n';
+import { ExpressionFunctionDefinition } from '../../../../../src/plugins/expressions/public';
+
+interface Arguments {
+  time: number;
+}
+
+export const sleep = (): ExpressionFunctionDefinition<'sleep', any, Arguments, any> => ({
+  name: 'sleep',
+  help: i18n.translate('expressionsExample.function.sleep.help', {
+    defaultMessage: 'Generates range object',
+  }),
+  args: {
+    time: {
+      types: ['number'],
+      help: i18n.translate('expressionsExample.function.sleep.time.help', {
+        defaultMessage: 'Time for settimeout',
+      }),
+      required: false,
+    },
+  },
+  fn: async (input, args, context) => {
+    await new Promise((r) => setTimeout(r, args.time));
+    return input;
+  },
+});

examples/expressions_example/common/expression_functions/basic/square.ts

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { i18n } from '@osd/i18n';
+import { ExpressionFunctionDefinition } from '../../../../../src/plugins/expressions/public';
+
+export const square = (): ExpressionFunctionDefinition<'square', number, {}, any> => ({
+  name: 'square',
+  help: i18n.translate('expressionsExample.function.square.help', {
+    defaultMessage: 'Squares the input',
+  }),
+  args: {},
+  fn: async (input, args, context) => {
+    return input * input;
+  },
+});

examples/expressions_example/common/expression_functions/index.ts

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export * from './basic';
+export * from './render';
+export * from './action';

examples/expressions_example/common/expression_functions/render/avatar_fn.ts

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { i18n } from '@osd/i18n';
+import {
+  ExpressionFunctionDefinition,
+  Render,
+} from '../../../../../src/plugins/expressions/public';
+import { AvatarRenderValue } from './avatar_renderer';
+
+type Arguments = AvatarRenderValue;
+
+export const avatarFn = (): ExpressionFunctionDefinition<
+  'avatar',
+  unknown,
+  Arguments,
+  Render<AvatarRenderValue>
+> => ({
+  name: 'avatar',
+  type: 'render',
+  help: i18n.translate('expressionsExample.function.avatar.help', {
+    defaultMessage: 'Avatar expression function',
+  }),
+  args: {
+    name: {
+      types: ['string'],
+      help: i18n.translate('expressionsExample.function.avatar.args.name.help', {
+        defaultMessage: 'Enter Name',
+      }),
+      required: true,
+    },
+    size: {
+      types: ['string'],
+      help: i18n.translate('expressionsExample.function.avatar.args.size.help', {
+        defaultMessage: 'Size of the avatar',
+      }),
+      default: 'l',
+    },
+  },
+  fn: (input, args) => {
+    return {
+      type: 'render',
+      as: 'avatar',
+      value: {
+        name: args.name,
+        size: args.size,
+      },
+    };
+  },
+});

examples/expressions_example/common/expression_functions/render/avatar_renderer.tsx

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import React from 'react';
+import { EuiAvatar, EuiAvatarProps } from '@elastic/eui';
+import { i18n } from '@osd/i18n';
+import { render, unmountComponentAtNode } from 'react-dom';
+import { ExpressionRenderDefinition } from '../../../../../src/plugins/expressions/public';
+
+export interface AvatarRenderValue {
+  name: string;
+  size: EuiAvatarProps['size'];
+}
+
+export const avatar: ExpressionRenderDefinition<AvatarRenderValue> = {
+  name: 'avatar',
+  displayName: i18n.translate('expressionsExample.render.help', {
+    defaultMessage: 'Render an avatar',
+  }),
+  reuseDomNode: true,
+  render: (domNode, { name, size }, handlers) => {
+    handlers.onDestroy(() => {
+      unmountComponentAtNode(domNode);
+    });
+
+    render(<EuiAvatar size={size} name={name} />, domNode, handlers.done);
+  },
+};

examples/expressions_example/common/expression_functions/render/index.ts

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export * from './avatar_fn';
+export * from './avatar_renderer';

examples/expressions_example/common/index.ts

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export const PLUGIN_ID = 'expressionsExample';
+export const PLUGIN_NAME = 'expressions_example';

examples/expressions_example/opensearch_dashboards.json

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+{
+  "id": "expressionsExample",
+  "version": "1.0.0",
+  "opensearchDashboardsVersion": "opensearchDashboards",
+  "server": false,
+  "ui": true,
+  "requiredPlugins": [
+    "navigation",
+    "expressions",
+    "developerExamples",
+    "opensearchDashboardsReact"
+  ],
+  "optionalPlugins": []
+}

examples/expressions_example/public/application.tsx

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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import React from 'react';
+import ReactDOM from 'react-dom';
+import { AppMountParameters, CoreStart } from '../../../src/core/public';
+import { ExpressionsExampleStartDependencies } from './types';
+import { ExpressionsExampleApp } from './components/app';
+import { OpenSearchDashboardsContextProvider } from '../../../src/plugins/opensearch_dashboards_react/public';
+
+export const renderApp = (
+  { notifications, http }: CoreStart,
+  { navigation, expressions }: ExpressionsExampleStartDependencies,
+  { appBasePath, element }: AppMountParameters
+) => {
+  const services = { expressions, notifications };
+  ReactDOM.render(
+    <OpenSearchDashboardsContextProvider services={services}>
+      <ExpressionsExampleApp
+        basename={appBasePath}
+        notifications={notifications}
+        http={http}
+        navigation={navigation}
+      />
+    </OpenSearchDashboardsContextProvider>,
+    element
+  );
+
+  return () => ReactDOM.unmountComponentAtNode(element);
+};