[Dashboard] [Controls] Load more options list suggestions on scroll (#…

…148331)

Closes #140175
Closes #143580

## Summary

Oh, boy! Get ready for a doozy of a PR, folks! Let's talk about the
three major things that were accomplished here:

### 1) Pagination
Originally, this PR was meant to add traditional pagination to the
options list control. However, after implementing a version of this, it
became apparent that, not only was UI becoming uncomfortably messy, it
also had some UX concerns because we were deviating from the usual
pagination pattern by showing the cardinality rather than the number of
pages:
    
<p align="center"><img
src="https://user-images.githubusercontent.com/8698078/214687041-f8950d3a-2b29-41d5-b656-c79d9575d744.gif"/></p>
    
So, instead of traditional pagination, we decided to take a different
approach (which was made possible by
#148420) - **load more options
when the user scrolls to the bottom!** Here it is in action:
    
<p align="center"><img
src="https://user-images.githubusercontent.com/8698078/214688854-06c7e8a9-7b8c-4dc0-9846-00ccf5e5f771.gif"/></p>

It is important that the first query remains **fast** - that is why we
still only request the top 10 options when the control first loads. So,
having a "load more" is the best approach that allows users to see more
suggestions while also ensuring that the performance of options lists
(especially with respect to chaining) is not impacted.

Note that it is **not possible** to grab every single value of a field -
the limit is `10,000`. However, since it is impractical that a user
would want to scroll through `10,000` suggestions (and potentially very
slow to fetch), we have instead made the limit of this "show more"
functionality `1,000`. To make this clear, if the field has more than
`1,000` values and the user scrolls all the way to the bottom, they will
get the following message:


<p align="center"><img
src="https://user-images.githubusercontent.com/8698078/214920302-1e3574dc-f2b6-4845-be69-f9ba04177e7f.png"/></p>


### 2) Cardinality
Previously, the cardinality of the options list control was **only**
shown as part of the control placeholder text - this meant that, once
the user entered their search term, they could no longer see the
cardinality of the returned options. This PR changes this functionality
by placing the cardinality in a badge **beside** the search bar - this
value now changes as the user types, so they can very clearly see how
many options match their search:

<p align="center"><img
src="https://user-images.githubusercontent.com/8698078/214689739-9670719c-5878-4e8b-806c-0b5a6f6f907f.gif"/></p>

> **Note**
> After some initial feedback, we have removed both the cardinality and
invalid selections badges in favour of displaying the cardinality below
the search bar, like so:
> 
> <p align="center"><img
src="https://user-images.githubusercontent.com/8698078/216473930-e99366a3-86df-4777-a3d8-cf2d41e550fb.gif"/></p>
> 
> So,  please be aware that the screenshots above are outdated.


### 3) Changes to Queries
This is where things get.... messy! Essentially, our previous queries
were all built with the expectation that the Elasticsearch setting
`search.allow_expensive_queries` was **off** - this meant that they
worked regardless of the value of this setting. However, when trying to
get the cardinality to update based on a search term, it became apparent
that this was not possible if we kept the same assumptions -
specifically, if `search.allow_expensive_queries` is off, there is
absolutely no way for the cardinality of **keyword only fields** to
respond to a search term.

After a whole lot of discussion, we decided that the updating
cardinality was a feature important enough to justify having **two
separate versions** of the queries:
1. **Queries for when `search.allow_expensive_queries` is off**:
These are essentially the same as our old queries - however, since we
can safely assume that this setting is **usually** on (it defaults on,
and there is no UI to easily change it), we opted to simplify them a
bit.
     
First of all, we used to create a special object for tracking the
parent/child relationship of fields that are mapped as keyword+text -
this was so that, if a user created a control on these fields, we could
support case-insensitive search. We no longer do this - if
`search.allow_expensive_queries` is off and you create a control on a
text+keyword field, the search will be case sensitive. This helps clean
up our code quite a bit.
     
Second, we are no longer returning **any** cardinality. Since the
cardinality is now displayed as a badge beside the search bar, users
would expect that this value would change as they type - however, since
it's impossible to make this happen for keyword-only fields and to keep
behaviour consistent, we have opted to simply remove this badge when
`search.allow_expensive_queries` is off **regardless** of the field
type. So, there is no longer a need to include the `cardinality` query
when grabbing the suggestions.

Finally, we do not support "load more" when
`search.allow_expensive_queries` is off. While this would theoretically
be possible, because we are no longer grabbing the cardinality, we would
have to always fetch `1,000` results when the user loads more, even if
the true cardinality is much smaller. Again, we are pretty confident
that **more often than not**, the `search.allow_expensive_queries` is
on; therefore, we are choosing to favour developer experience in this
instance because the impact should be quite small.
     
2. **Queries for when `search.allow_expensive_queries` is on**:
When this setting is on, we now have access to the prefix query, which
greatly simplifies how our queries are handled - now, rather than having
separate queries for keyword-only, keyword+text, and nested fields,
these have all been combined into a single query! And even better -
:star: now **all** string-based fields support case-insensitive search!
:star: Yup, that's right - even keyword-only fields 💃

There has been [discussion on the Elasticsearch side
](elastic/elasticsearch#90898) about whether
or not this setting is even **practical**, and so it is possible that,
in the near future, this distinction will no longer be necessary. With
this in mind, I have made these two versions of our queries **completely
separate** from each other - while this introduces some code
duplication, it makes the cleanup that may follow much, much easier.

Well, that was sure fun, hey?

<p align="center"><img
src="https://user-images.githubusercontent.com/8698078/214921985-49058ff0-42f2-4b01-8ae3-0a4d259d1075.gif"/></p>


## How to Test
I've created a quick little Python program to ingest some good testing
data for this PR:

```python
import random
import time
import pandas as pd
from faker import Faker
from elasticsearch import Elasticsearch

SIZE = 10000
ELASTIC_PASSWORD = "changeme"
INDEX_NAME = 'test_large_index'

Faker.seed(time.time())
faker = Faker()
hundredRandomSentences = [faker.sentence(random.randint(5, 35)) for _ in range(100)]
thousandRandomIps = [faker.ipv4() if random.randint(0, 99) < 50 else faker.ipv6() for _ in range(1000)]

client = Elasticsearch(
    "http://localhost:9200",
    basic_auth=("elastic", ELASTIC_PASSWORD),
)

if(client.indices.exists(index=INDEX_NAME)):
    client.indices.delete(index=INDEX_NAME)
client.indices.create(index=INDEX_NAME, mappings={"properties":{"keyword_field":{"type":"keyword"},"id":{"type":"long"},"ip_field":{"type":"ip"},"boolean_field":{"type":"boolean"},"keyword_text_field":{"type":"text","fields":{"keyword":{"type":"keyword"}}},"nested_field":{"type":"nested","properties":{"first":{"type":"text","fields":{"keyword":{"type":"keyword"}}},"last":{"type":"text","fields":{"keyword":{"type":"keyword"}}}}},"long_keyword_text_field":{"type":"text","fields":{"keyword":{"type":"keyword"}}}}})

print('Generating data', end='')
for i in range(SIZE):
    name1 = faker.name();
    [first_name1, last_name1] = name1.split(' ', 1)
    name2 = faker.name();
    [first_name2, last_name2] = name2.split(' ', 1)
    response = client.create(index=INDEX_NAME, id=i, document={
        'keyword_field': faker.country(),
        'id': i,
        'boolean_field': faker.boolean(),
        'ip_field': thousandRandomIps[random.randint(0, 999)],
        'keyword_text_field': faker.name(),
        'nested_field': [
            { 'first': first_name1, 'last': last_name1},
            { 'first': first_name2, 'last': last_name2}
        ],
        'long_keyword_text_field': hundredRandomSentences[random.randint(0, 99)]
    })
    print('.', end='')
print(' Done!')
```
However, if you don't have Python up and running, here's a CSV with a
smaller version of this data:
[testNewQueriesData.csv](https://github.com/elastic/kibana/files/10538537/testNewQueriesData.csv)

> **Warning**
> When uploading, make sure to update the mappings of the CSV data to
the mappings included as part of the Python script above (which you can
find as part of the `client.indices.create` call). You'll notice,
however, that **none of the CSV documents have a nested field**.
Unfortunately, there doesn't seem to be a way to able to ingest nested
data through uploading a CSV, so the above data does not include one -
in order to test the nested data type, you'd have to add some of your
own documents
>
> Here's a sample nested field document, for your convenience:
> ```json
> {
>     "keyword_field": "Russian Federation",
>     "id": 0,
>     "boolean_field": true,
>     "ip_field": "121.149.70.251",
>     "keyword_text_field": "Michael Foster",
>     "nested_field": [
>       {
>         "first": "Rachel",
>         "last": "Wright"
>       },
>       {
>         "first": "Gary",
>         "last": "Reyes"
>       }
>     ],
> "long_keyword_text_field": "Color hotel indicate appear since well
sure right yet individual easy often test enough left a usually
attention."
> }
> ```
> 

### Testing Notes
Because there are now two versions of the queries, thorough testing
should be done for both when `search.allow_expensive_queries` is `true`
and when it is `false` for every single field type that is currently
supported. Use the following call to the cluster settings API to toggle
this value back and forth:

```php
PUT _cluster/settings
{
  "transient": {
	"search.allow_expensive_queries": <value> // true or false
  }
}
```

You should pay super special attention to the behaviour that happens
when toggling this value from `true` to `false` - for example, consider
the following:
1. Ensure `search.allow_expensive_queries` is either `true` or
`undefined`
2. Create and save a dashboard with at least one options list control
3. Navigate to the console and set `search.allow_expensive_queries` to
`false` - **DO NOT REFRESH**
4. Go back to the dashboard
5. Open up the options list control you created in step 2
6. Fetch a new, uncached request, either by scrolling to the bottom and
fetching more (assuming these values aren't already in the cache) or by
performing a search with a string you haven't tried before
7. ⚠️ **The options list control _should_ have a fatal error** ⚠️<br>The
Elasticsearch server knows that `search.allow_expensive_queries` is now
`false` but, because we only fetch this value on the first load on the
client side, it has not yet been updated - this means the options list
service still tries to fetch the suggestions using the expensive version
of the queries despite the fact that Elasticsearch will now reject this
request. The most graceful way to handle this is to simply throw a fatal
error.
8. Refreshing the browser will make things sync up again and you should
now get the expected results when opening the options list control.

### Flaky Test Runner

<a
href="https://buildkite.com/elastic/kibana-flaky-test-suite-runner/builds/1845"><img
src="https://user-images.githubusercontent.com/8698078/215894267-97f07e59-6660-4117-bda7-18f63cb19af6.png"/></a>

### Checklist

- [x] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/packages/kbn-i18n/README.md)
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [x] Any UI touched in this PR is usable by keyboard only (learn more
about [keyboard accessibility](https://webaim.org/techniques/keyboard/))
- [x] Any UI touched in this PR does not create any new axe failures
(run axe in browser:
[FF](https://addons.mozilla.org/en-US/firefox/addon/axe-devtools/),
[Chrome](https://chrome.google.com/webstore/detail/axe-web-accessibility-tes/lhdoppojpmngadmnindnejefpokejbdd?hl=en-US))
     > **Note**
> Technically, it actually does - however, it is due to an [EUI
bug](elastic/eui#6565) from adding the group
label to the bottom of the list.
- [x] This renders correctly on smaller devices using a responsive
layout. (You can test this [in your
browser](https://www.browserstack.com/guide/responsive-testing-on-local-server))
- [x] This was checked for [cross-browser
compatibility](https://www.elastic.co/support/matrix#matrix_browsers)


### For maintainers

- [ ] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

---------

Co-authored-by: kibanamachine <[email protected]>

src/plugins/controls/common/options_list/types.ts

@@ -9,8 +9,8 @@
 import { FieldSpec, DataView, RuntimeFieldSpec } from '@kbn/data-views-plugin/common';
 import type { Filter, Query, BoolQuery, TimeRange } from '@kbn/es-query';
 
-import { OptionsListSortingType } from './suggestions_sorting';
-import { DataControlInput } from '../types';
+import type { OptionsListSortingType } from './suggestions_sorting';
+import type { DataControlInput } from '../types';
 
 export const OPTIONS_LIST_CONTROL = 'optionsListControl';
 
@@ -20,46 +20,55 @@ export interface OptionsListEmbeddableInput extends DataControlInput {
   existsSelected?: boolean;
   runPastTimeout?: boolean;
   singleSelect?: boolean;
+  hideActionBar?: boolean;
   hideExclude?: boolean;
   hideExists?: boolean;
   hideSort?: boolean;
-  hideActionBar?: boolean;
   exclude?: boolean;
   placeholder?: string;
 }
 
-export type OptionsListField = FieldSpec & {
-  textFieldName?: string;
-  parentFieldName?: string;
-  childFieldName?: string;
-};
-
 export interface OptionsListSuggestions {
   [key: string]: { doc_count: number };
 }
 
 /**
  * The Options list response is returned from the serverside Options List route.
  */
-export interface OptionsListResponse {
-  rejected: boolean;
+export interface OptionsListSuccessResponse {
   suggestions: OptionsListSuggestions;
-  totalCardinality: number;
+  totalCardinality?: number; // total cardinality will be undefined when `useExpensiveQueries` is `false`
   invalidSelections?: string[];
 }
 
+/**
+ * The invalid selections are parsed **after** the server returns with the result from the ES client; so, the
+ * suggestion aggregation parser only returns the suggestions list + the cardinality of the result
+ */
+export type OptionsListParsedSuggestions = Pick<
+  OptionsListSuccessResponse,
+  'suggestions' | 'totalCardinality'
+>;
+
+export interface OptionsListFailureResponse {
+  error: 'aborted' | Error;
+}
+
+export type OptionsListResponse = OptionsListSuccessResponse | OptionsListFailureResponse;
+
 /**
  * The Options list request type taken in by the public Options List service.
  */
 export type OptionsListRequest = Omit<
   OptionsListRequestBody,
   'filters' | 'fieldName' | 'fieldSpec' | 'textFieldName'
 > & {
+  allowExpensiveQueries: boolean;
   timeRange?: TimeRange;
-  field: OptionsListField;
   runPastTimeout?: boolean;
   dataView: DataView;
   filters?: Filter[];
+  field: FieldSpec;
   query?: Query;
 };
 
@@ -68,13 +77,13 @@ export type OptionsListRequest = Omit<
  */
 export interface OptionsListRequestBody {
   runtimeFieldMap?: Record<string, RuntimeFieldSpec>;
+  allowExpensiveQueries: boolean;
   sort?: OptionsListSortingType;
   filters?: Array<{ bool: BoolQuery }>;
   selectedOptions?: string[];
   runPastTimeout?: boolean;
-  parentFieldName?: string;
-  textFieldName?: string;
   searchString?: string;
   fieldSpec?: FieldSpec;
   fieldName: string;
+  size: number;
 }

src/plugins/controls/common/types.ts

@@ -30,7 +30,5 @@ export type ControlInput = EmbeddableInput & {
 
 export type DataControlInput = ControlInput & {
   fieldName: string;
-  parentFieldName?: string;
-  childFieldName?: string;
   dataViewId: string;
 };

src/plugins/controls/public/__stories__/controls.stories.tsx

@@ -61,7 +61,6 @@ const storybookStubOptionsListRequest = async (
             {}
           ),
           totalCardinality: 100,
-          rejected: false,
         }),
       120
     )

src/plugins/controls/public/control_group/component/control_frame_component.tsx

@@ -9,15 +9,13 @@
 import React, { useEffect, useMemo, useState } from 'react';
 import classNames from 'classnames';
 import {
+  EuiButtonEmpty,
   EuiButtonIcon,
   EuiFormControlLayout,
   EuiFormLabel,
   EuiFormRow,
-  EuiIcon,
-  EuiLink,
   EuiLoadingChart,
   EuiPopover,
-  EuiText,
   EuiToolTip,
 } from '@elastic/eui';
 
@@ -40,25 +38,26 @@ interface ControlFrameErrorProps {
 const ControlFrameError = ({ error }: ControlFrameErrorProps) => {
   const [isPopoverOpen, setPopoverOpen] = useState(false);
   const popoverButton = (
-    <EuiText className="errorEmbeddableCompact__button" size="xs">
-      <EuiLink
-        className="eui-textTruncate"
-        color="subdued"
-        onClick={() => setPopoverOpen((open) => !open)}
-      >
-        <EuiIcon type="alert" color="danger" />
-        <FormattedMessage
-          id="controls.frame.error.message"
-          defaultMessage="An error has occurred. Read more"
-        />
-      </EuiLink>
-    </EuiText>
+    <EuiButtonEmpty
+      color="danger"
+      iconSize="m"
+      iconType={'alert'}
+      onClick={() => setPopoverOpen((open) => !open)}
+      className={'errorEmbeddableCompact__button'}
+      textProps={{ className: 'errorEmbeddableCompact__text' }}
+    >
+      <FormattedMessage
+        id="controls.frame.error.message"
+        defaultMessage="An error occurred. View more"
+      />
+    </EuiButtonEmpty>
   );
 
   return (
     <EuiPopover
       button={popoverButton}
       isOpen={isPopoverOpen}
+      className="errorEmbeddableCompact__popover"
       anchorClassName="errorEmbeddableCompact__popoverAnchor"
       closePopover={() => setPopoverOpen(false)}
     >

src/plugins/controls/public/control_group/editor/control_editor.tsx

@@ -199,11 +199,8 @@ export const ControlEditor = ({
               selectedFieldName={selectedField}
               dataView={dataView}
               onSelectField={(field) => {
-                const { parentFieldName, childFieldName } = fieldRegistry?.[field.name] ?? {};
                 onTypeEditorChange({
                   fieldName: field.name,
-                  ...(parentFieldName && { parentFieldName }),
-                  ...(childFieldName && { childFieldName }),
                 });
                 const newDefaultTitle = field.displayName ?? field.name;
                 setDefaultTitle(newDefaultTitle);

src/plugins/controls/public/control_group/editor/data_control_editor_tools.ts

@@ -8,11 +8,10 @@
 
 import { memoize } from 'lodash';
 
-import { IFieldSubTypeMulti } from '@kbn/es-query';
 import { DataView } from '@kbn/data-views-plugin/common';
 
 import { pluginServices } from '../../services';
-import { DataControlFieldRegistry, IEditableControlFactory } from '../../types';
+import { DataControlField, DataControlFieldRegistry, IEditableControlFactory } from '../../types';
 
 export const getDataControlFieldRegistry = memoize(
   async (dataView: DataView) => {
@@ -21,50 +20,30 @@ export const getDataControlFieldRegistry = memoize(
   (dataView: DataView) => [dataView.id, JSON.stringify(dataView.fields.getAll())].join('|')
 );
 
-const doubleLinkFields = (dataView: DataView) => {
-  // double link the parent-child relationship specifically for case-sensitivity support for options lists
-  const fieldRegistry: DataControlFieldRegistry = {};
-
-  for (const field of dataView.fields.getAll()) {
-    if (!fieldRegistry[field.name]) {
-      fieldRegistry[field.name] = { field, compatibleControlTypes: [] };
-    }
-
-    const parentFieldName = (field.subType as IFieldSubTypeMulti)?.multi?.parent;
-    if (parentFieldName) {
-      fieldRegistry[field.name].parentFieldName = parentFieldName;
-
-      const parentField = dataView.getFieldByName(parentFieldName);
-      if (!fieldRegistry[parentFieldName] && parentField) {
-        fieldRegistry[parentFieldName] = { field: parentField, compatibleControlTypes: [] };
-      }
-      fieldRegistry[parentFieldName].childFieldName = field.name;
-    }
-  }
-  return fieldRegistry;
-};
-
 const loadFieldRegistryFromDataView = async (
   dataView: DataView
 ): Promise<DataControlFieldRegistry> => {
   const {
     controls: { getControlTypes, getControlFactory },
   } = pluginServices.getServices();
-  const newFieldRegistry: DataControlFieldRegistry = doubleLinkFields(dataView);
+
   const controlFactories = getControlTypes().map(
     (controlType) => getControlFactory(controlType) as IEditableControlFactory
   );
-  dataView.fields.map((dataViewField) => {
-    for (const factory of controlFactories) {
-      if (factory.isFieldCompatible) {
-        factory.isFieldCompatible(newFieldRegistry[dataViewField.name]);
+  const fieldRegistry: DataControlFieldRegistry = dataView.fields
+    .getAll()
+    .reduce((registry, field) => {
+      const test: DataControlField = { field, compatibleControlTypes: [] };
+      for (const factory of controlFactories) {
+        if (factory.isFieldCompatible) {
+          factory.isFieldCompatible(test);
+        }
       }
-    }
-
-    if (newFieldRegistry[dataViewField.name]?.compatibleControlTypes.length === 0) {
-      delete newFieldRegistry[dataViewField.name];
-    }
-  });
+      if (test.compatibleControlTypes.length === 0) {
+        return { ...registry };
+      }
+      return { ...registry, [field.name]: test };
+    }, {});
 
-  return newFieldRegistry;
+  return fieldRegistry;
 };

src/plugins/controls/public/options_list/components/options_list.scss

@@ -9,8 +9,18 @@
 
 .optionsList__actions {
   padding: $euiSizeS;
+  padding-bottom: 0;
   border-bottom: $euiBorderThin;
   border-color: darken($euiColorLightestShade, 2%);
+
+  .optionsList__actionsRow {
+    margin: ($euiSizeS / 2) 0 !important;
+
+    .optionsList__actionBarDivider {
+      height: $euiSize;
+      border-right: $euiBorderThin;
+    }
+  }
 }
 
 .optionsList__popoverTitle {
@@ -30,13 +40,17 @@
   font-style: italic;
 }
 
+.optionsList__loadMore {
+  font-style: italic;
+}
+
 .optionsList__negateLabel {
   font-weight: bold;
   font-size: $euiSizeM;
   color: $euiColorDanger;
 }
 
-.optionsList__ignoredBadge {
+.optionsList__actionBarFirstBadge {
   margin-left: $euiSizeS;
 }
 
@@ -86,3 +100,18 @@
 .optionsList--sortPopover {
   width: $euiSizeXL * 7;
 }
+
+.optionslist--loadingMoreGroupLabel {
+  text-align: center;
+  padding: $euiSizeM;
+  font-style: italic;
+  height:  $euiSizeXXL !important;
+}
+
+.optionslist--endOfOptionsGroupLabel {
+  text-align: center;
+  font-size: $euiSizeM;
+  height:  auto !important;
+  color: $euiTextSubduedColor;
+  padding: $euiSizeM;
+}

src/plugins/controls/public/options_list/components/options_list_control.test.tsx

@@ -20,6 +20,7 @@ import { BehaviorSubject } from 'rxjs';
 describe('Options list control', () => {
   const defaultProps = {
     typeaheadSubject: new BehaviorSubject(''),
+    loadMoreSubject: new BehaviorSubject(10),
   };
 
   interface MountOptions {