feat: implement script component

Related to #1102

packages/form-js-editor/src/features/properties-panel/entries/ConditionEntry.js

@@ -50,7 +50,7 @@ function Condition(props) {
   let description = 'Condition under which the field is hidden';
 
   // special case for expression fields which do not render
-  if (field.type === 'expression') {
+  if ([ 'expression', 'script' ].includes(field.type)) {
     label = 'Deactivate if';
     description = 'Condition under which the field is deactivated';
   }

packages/form-js-editor/src/features/properties-panel/entries/JSFunctionEntry.js

@@ -0,0 +1,139 @@
+import { FeelEntry, isFeelEntryEdited, TextAreaEntry, isTextAreaEntryEdited, ToggleSwitchEntry, isToggleSwitchEntryEdited } from '@bpmn-io/properties-panel';
+import { get } from 'min-dash';
+
+import { useService, useVariables } from '../hooks';
+
+export function JSFunctionEntry(props) {
+  const {
+    editField,
+    field
+  } = props;
+
+  const entries = [
+    {
+      id: 'variable-mappings',
+      component: FunctionParameters,
+      editField: editField,
+      field: field,
+      isEdited: isFeelEntryEdited,
+      isDefaultVisible: (field) => field.type === 'script'
+    },
+    {
+      id: 'function',
+      component: FunctionDefinition,
+      editField: editField,
+      field: field,
+      isEdited: isTextAreaEntryEdited,
+      isDefaultVisible: (field) => field.type === 'script'
+    },
+    {
+      id: 'on-load-only',
+      component: OnLoadOnlyEntry,
+      editField: editField,
+      field: field,
+      isEdited: isToggleSwitchEntryEdited,
+      isDefaultVisible: (field) => field.type === 'script'
+    }
+  ];
+
+  return entries;
+}
+
+function FunctionParameters(props) {
+  const {
+    editField,
+    field,
+    id
+  } = props;
+
+  const debounce = useService('debounce');
+
+  const variables = useVariables().map(name => ({ name }));
+
+  const path = [ 'functionParameters' ];
+
+  const getValue = () => {
+    return get(field, path, '');
+  };
+
+  const setValue = (value) => {
+    return editField(field, path, value || '');
+  };
+
+  const tooltip = <div>
+    Functions parameters should be described as an object, e.g.:
+    <pre><code>{`{
+      name: user.name,
+      age: user.age
+    }`}</code></pre>
+  </div>;
+
+  return FeelEntry({
+    debounce,
+    feel: 'required',
+    element: field,
+    getValue,
+    id,
+    label: 'Function parameters',
+    tooltip,
+    description: 'Define the parameters to pass to the javascript context.',
+    setValue,
+    variables
+  });
+}
+
+function FunctionDefinition(props) {
+  const {
+    editField,
+    field,
+    id
+  } = props;
+
+  const debounce = useService('debounce');
+
+  const path = [ 'jsFunction' ];
+
+  const getValue = () => {
+    return get(field, path, '');
+  };
+
+  const setValue = (value) => {
+    return editField(field, path, value || '');
+  };
+
+  return TextAreaEntry({
+    debounce,
+    element: field,
+    getValue,
+    description: 'Access function parameters via `data`, set results with `setValue`, and register cleanup functions with `onCleanup`.',
+    id,
+    label: 'Javascript code',
+    setValue
+  });
+}
+
+function OnLoadOnlyEntry(props) {
+  const {
+    editField,
+    field,
+    id
+  } = props;
+
+  const path = [ 'onLoadOnly' ];
+
+  const getValue = () => {
+    return !!get(field, path, false);
+  };
+
+  const setValue = (value) => {
+    editField(field, path, value);
+  };
+
+  return ToggleSwitchEntry({
+    element: field,
+    id,
+    label: 'Execute on load only',
+    getValue,
+    setValue
+  });
+}

packages/form-js-editor/src/features/properties-panel/entries/index.js

@@ -14,6 +14,7 @@ export { IFrameUrlEntry } from './IFrameUrlEntry';
 export { ImageSourceEntry } from './ImageSourceEntry';
 export { TextEntry } from './TextEntry';
 export { HtmlEntry } from './HtmlEntry';
+export { JSFunctionEntry } from './JSFunctionEntry';
 export { HeightEntry } from './HeightEntry';
 export { NumberEntries } from './NumberEntries';
 export { ExpressionFieldEntries } from './ExpressionFieldEntries';

packages/form-js-editor/src/features/properties-panel/groups/GeneralGroup.js

@@ -19,6 +19,7 @@ import {
   HeightEntry,
   NumberEntries,
   ExpressionFieldEntries,
+  JSFunctionEntry,
   DateTimeEntry,
   TableDataSourceEntry,
   PaginationEntry,
@@ -45,6 +46,7 @@ export function GeneralGroup(field, editField, getService) {
     ...HeightEntry({ field, editField }),
     ...NumberEntries({ field, editField }),
     ...ExpressionFieldEntries({ field, editField }),
+    ...JSFunctionEntry({ field, editField }),
     ...ImageSourceEntry({ field, editField }),
     ...AltTextEntry({ field, editField }),
     ...SelectEntries({ field, editField }),

packages/form-js-editor/src/render/components/editor-form-fields/EditorJSFunctionField.js

@@ -0,0 +1,30 @@
+import { JSFunctionField, iconsByType } from '@bpmn-io/form-js-viewer';
+import { editorFormFieldClasses } from '../Util';
+
+const type = 'script';
+
+export function EditorJSFunctionField(props) {
+  const { field } = props;
+  const { jsFunction = '' } = field;
+
+  const Icon = iconsByType(type);
+
+  let placeholderContent = 'JS function is empty';
+
+  if (jsFunction.trim()) {
+    placeholderContent = 'JS function';
+  }
+
+  return (
+    <div class={ editorFormFieldClasses(type) }>
+      <div class="fjs-form-field-placeholder">
+        <Icon viewBox="0 0 54 54" />{placeholderContent}
+      </div>
+    </div>
+  );
+}
+
+EditorJSFunctionField.config = {
+  ...JSFunctionField.config,
+  escapeGridRender: false
+};

packages/form-js-editor/src/render/components/editor-form-fields/index.js

@@ -3,11 +3,13 @@ import { EditorText } from './EditorText';
 import { EditorHtml } from './EditorHtml';
 import { EditorTable } from './EditorTable';
 import { EditorExpressionField } from './EditorExpressionField';
+import { EditorJSFunctionField } from './EditorJSFunctionField';
 
 export const editorFormFields = [
   EditorIFrame,
   EditorText,
   EditorHtml,
   EditorTable,
-  EditorExpressionField
+  EditorExpressionField,
+  EditorJSFunctionField
 ];

packages/form-js-viewer/src/render/components/form-fields/JSFunctionField.js

@@ -0,0 +1,79 @@
+import { useCallback, useEffect, useState } from 'preact/hooks';
+import { useExpressionEvaluation, useDeepCompareMemoize, usePrevious } from '../../hooks';
+import { isObject } from 'min-dash';
+
+const type = 'script';
+
+export function JSFunctionField(props) {
+  const { field, onChange } = props;
+  const { jsFunction, functionParameters, onLoadOnly } = field;
+
+  const [ loadLatch, setLoadLatch ] = useState(false);
+
+  const paramsEval = useExpressionEvaluation(functionParameters);
+  const params = useDeepCompareMemoize(isObject(paramsEval) ? paramsEval : {});
+
+  const functionMemo = useCallback((params) => {
+
+    const cleanupCallbacks = [];
+
+    try {
+
+      setLoadLatch(true);
+      const func = new Function('data', 'setValue', 'onCleanup', jsFunction);
+      func(params, value => onChange({ field, value }), callback => cleanupCallbacks.push(callback));
+
+    } catch (error) {
+
+      // invalid expression definition, may happen during editing
+      if (error instanceof SyntaxError) {
+        return;
+      }
+
+      console.error('Error evaluating expression:', error);
+      onChange({ field, value: null });
+    }
+
+    return () => {
+      cleanupCallbacks.forEach(fn => fn());
+    };
+
+  }, [ jsFunction, field, onChange ]);
+
+  const previousFunctionMemo = usePrevious(functionMemo);
+  const previousParams = usePrevious(params);
+
+  useEffect(() => {
+
+    // reset load latch
+    if (!onLoadOnly && loadLatch) {
+      setLoadLatch(false);
+    }
+
+    const functionChanged = previousFunctionMemo !== functionMemo;
+    const paramsChanged = previousParams !== params;
+    const alreadyLoaded = onLoadOnly && loadLatch;
+
+    const shouldExecute = functionChanged || paramsChanged && !alreadyLoaded;
+
+    if (shouldExecute) {
+      return functionMemo(params);
+    }
+
+  }, [ previousFunctionMemo, functionMemo, previousParams, params, loadLatch, onLoadOnly ]);
+
+  return null;
+}
+
+JSFunctionField.config = {
+  type,
+  label: 'JS Function',
+  group: 'basic-input',
+  keyed: true,
+  escapeGridRender: true,
+  create: (options = {}) => ({
+    jsFunction: 'setValue(data.value)',
+    functionParameters: '={\n  value: 42\n}',
+    ...options,
+  })
+};

packages/form-js-viewer/src/render/components/icons/index.js

@@ -13,6 +13,7 @@ import SpacerIcon from './Spacer.svg';
 import DynamicListIcon from './DynamicList.svg';
 import TextIcon from './Text.svg';
 import HTMLIcon from './HTML.svg';
+import JsFunctionIcon from './JSFunction.svg';
 import ExpressionFieldIcon from './ExpressionField.svg';
 import TextfieldIcon from './Textfield.svg';
 import TextareaIcon from './Textarea.svg';
@@ -41,6 +42,7 @@ export const iconsByType = (type) => {
     taglist: TaglistIcon,
     text: TextIcon,
     html: HTMLIcon,
+    script: JsFunctionIcon,
     textfield: TextfieldIcon,
     textarea: TextareaIcon,
     table: TableIcon,

packages/form-js-viewer/src/render/components/index.js

@@ -16,6 +16,7 @@ import { Taglist } from './form-fields/Taglist';
 import { Text } from './form-fields/Text';
 import { Html } from './form-fields/Html';
 import { ExpressionField } from './form-fields/ExpressionField';
+import { JSFunctionField } from './form-fields/JSFunctionField';
 import { Textfield } from './form-fields/Textfield';
 import { Textarea } from './form-fields/Textarea';
 import { Table } from './form-fields/Table';
@@ -46,6 +47,7 @@ export {
   Image,
   Numberfield,
   ExpressionField,
+  JSFunctionField,
   Radio,
   Select,
   Separator,
@@ -72,6 +74,7 @@ export const formFields = [
   Textfield,
   Textarea,
   ExpressionField,
+  JSFunctionField,
   Text,
   Image,
   Table,