feat(combobox): added expression support to combobox (#2697)

* feat(combobox): added expression support to combobox

* fix chat messages styling in light mode

* last sec stuff

* ack comments

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/chat/components/chat-message/chat-message.tsx

@@ -157,7 +157,7 @@ export function ChatMessage({ message }: ChatMessageProps) {
 
         {formattedContent && !formattedContent.startsWith('Uploaded') && (
           <div className='rounded-[4px] border border-[var(--border-1)] bg-[var(--surface-5)] px-[8px] py-[6px] transition-all duration-200'>
-            <div className='whitespace-pre-wrap break-words font-medium font-sans text-gray-100 text-sm leading-[1.25rem]'>
+            <div className='whitespace-pre-wrap break-words font-medium font-sans text-[var(--text-primary)] text-sm leading-[1.25rem]'>
               <WordWrap text={formattedContent} />
             </div>
           </div>
@@ -168,7 +168,7 @@ export function ChatMessage({ message }: ChatMessageProps) {
 
   return (
     <div className='w-full max-w-full overflow-hidden pl-[2px] opacity-100 transition-opacity duration-200'>
-      <div className='whitespace-pre-wrap break-words font-[470] font-season text-[#E8E8E8] text-sm leading-[1.25rem]'>
+      <div className='whitespace-pre-wrap break-words font-[470] font-season text-[var(--text-primary)] text-sm leading-[1.25rem]'>
         <WordWrap text={formattedContent} />
         {message.isStreaming && <StreamingIndicator />}
       </div>

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/combobox/combobox.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useMemo, useState } from 'react'
+import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 import { useReactFlow } from 'reactflow'
 import { Combobox, type ComboboxOption } from '@/components/emcn/components'
 import { cn } from '@/lib/core/utils/cn'
@@ -7,6 +7,9 @@ import { SubBlockInputController } from '@/app/workspace/[workspaceId]/w/[workfl
 import { useSubBlockValue } from '@/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/hooks/use-sub-block-value'
 import { useAccessibleReferencePrefixes } from '@/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-accessible-reference-prefixes'
 import type { SubBlockConfig } from '@/blocks/types'
+import { getDependsOnFields } from '@/blocks/utils'
+import { useWorkflowRegistry } from '@/stores/workflows/registry/store'
+import { useSubBlockStore } from '@/stores/workflows/subblock/store'
 
 /**
  * Constants for ComboBox component behavior
@@ -48,6 +51,19 @@ interface ComboBoxProps {
   placeholder?: string
   /** Configuration for the sub-block */
   config: SubBlockConfig
+  /** Async function to fetch options dynamically */
+  fetchOptions?: (
+    blockId: string,
+    subBlockId: string
+  ) => Promise<Array<{ label: string; id: string }>>
+  /** Async function to fetch a single option's label by ID (for hydration) */
+  fetchOptionById?: (
+    blockId: string,
+    subBlockId: string,
+    optionId: string
+  ) => Promise<{ label: string; id: string } | null>
+  /** Field dependencies that trigger option refetch when changed */
+  dependsOn?: SubBlockConfig['dependsOn']
 }
 
 export function ComboBox({
@@ -61,23 +77,89 @@ export function ComboBox({
   disabled,
   placeholder = 'Type or select an option...',
   config,
+  fetchOptions,
+  fetchOptionById,
+  dependsOn,
 }: ComboBoxProps) {
   // Hooks and context
   const [storeValue, setStoreValue] = useSubBlockValue<string>(blockId, subBlockId)
   const accessiblePrefixes = useAccessibleReferencePrefixes(blockId)
   const reactFlowInstance = useReactFlow()
 
+  // Dependency tracking for fetchOptions
+  const dependsOnFields = useMemo(() => getDependsOnFields(dependsOn), [dependsOn])
+  const activeWorkflowId = useWorkflowRegistry((s) => s.activeWorkflowId)
+  const dependencyValues = useSubBlockStore(
+    useCallback(
+      (state) => {
+        if (dependsOnFields.length === 0 || !activeWorkflowId) return []
+        const workflowValues = state.workflowValues[activeWorkflowId] || {}
+        const blockValues = workflowValues[blockId] || {}
+        return dependsOnFields.map((depKey) => blockValues[depKey] ?? null)
+      },
+      [dependsOnFields, activeWorkflowId, blockId]
+    )
+  )
+
   // State management
   const [storeInitialized, setStoreInitialized] = useState(false)
+  const [fetchedOptions, setFetchedOptions] = useState<Array<{ label: string; id: string }>>([])
+  const [isLoadingOptions, setIsLoadingOptions] = useState(false)
+  const [fetchError, setFetchError] = useState<string | null>(null)
+  const [hydratedOption, setHydratedOption] = useState<{ label: string; id: string } | null>(null)
+  const previousDependencyValuesRef = useRef<string>('')
+
+  /**
+   * Fetches options from the async fetchOptions function if provided
+   */
+  const fetchOptionsIfNeeded = useCallback(async () => {
+    if (!fetchOptions || isPreview || disabled) return
+
+    setIsLoadingOptions(true)
+    setFetchError(null)
+    try {
+      const options = await fetchOptions(blockId, subBlockId)
+      setFetchedOptions(options)
+    } catch (error) {
+      const errorMessage = error instanceof Error ? error.message : 'Failed to fetch options'
+      setFetchError(errorMessage)
+      setFetchedOptions([])
+    } finally {
+      setIsLoadingOptions(false)
+    }
+  }, [fetchOptions, blockId, subBlockId, isPreview, disabled])
 
   // Determine the active value based on mode (preview vs. controlled vs. store)
   const value = isPreview ? previewValue : propValue !== undefined ? propValue : storeValue
 
-  // Evaluate options if provided as a function
+  // Evaluate static options if provided as a function
-  const evaluatedOptions = useMemo(() => {
+  const staticOptions = useMemo(() => {
     return typeof options === 'function' ? options() : options
   }, [options])
 
+  // Normalize fetched options to match ComboBoxOption format
+  const normalizedFetchedOptions = useMemo((): ComboBoxOption[] => {
+    return fetchedOptions.map((opt) => ({ label: opt.label, id: opt.id }))
+  }, [fetchedOptions])
+
+  // Merge static and fetched options - fetched options take priority when available
+  const evaluatedOptions = useMemo((): ComboBoxOption[] => {
+    let opts: ComboBoxOption[] =
+      fetchOptions && normalizedFetchedOptions.length > 0 ? normalizedFetchedOptions : staticOptions
+
+    // Merge hydrated option if not already present
+    if (hydratedOption) {
+      const alreadyPresent = opts.some((o) =>
+        typeof o === 'string' ? o === hydratedOption.id : o.id === hydratedOption.id
+      )
+      if (!alreadyPresent) {
+        opts = [hydratedOption, ...opts]
+      }
+    }
+
+    return opts
+  }, [fetchOptions, normalizedFetchedOptions, staticOptions, hydratedOption])
+
   // Convert options to Combobox format
   const comboboxOptions = useMemo((): ComboboxOption[] => {
     return evaluatedOptions.map((option) => {
@@ -160,6 +242,94 @@ export function ComboBox({
     }
   }, [storeInitialized, value, defaultOptionValue, setStoreValue])
 
+  // Clear fetched options and hydrated option when dependencies change
+  useEffect(() => {
+    if (fetchOptions && dependsOnFields.length > 0) {
+      const currentDependencyValuesStr = JSON.stringify(dependencyValues)
+      const previousDependencyValuesStr = previousDependencyValuesRef.current
+
+      if (
+        previousDependencyValuesStr &&
+        currentDependencyValuesStr !== previousDependencyValuesStr
+      ) {
+        setFetchedOptions([])
+        setHydratedOption(null)
+      }
+
+      previousDependencyValuesRef.current = currentDependencyValuesStr
+    }
+  }, [dependencyValues, fetchOptions, dependsOnFields.length])
+
+  // Fetch options when needed (on mount, when enabled, or when dependencies change)
+  useEffect(() => {
+    if (
+      fetchOptions &&
+      !isPreview &&
+      !disabled &&
+      fetchedOptions.length === 0 &&
+      !isLoadingOptions &&
+      !fetchError
+    ) {
+      fetchOptionsIfNeeded()
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps -- fetchOptionsIfNeeded deps already covered above
+  }, [
+    fetchOptions,
+    isPreview,
+    disabled,
+    fetchedOptions.length,
+    isLoadingOptions,
+    fetchError,
+    dependencyValues,
+  ])
+
+  // Hydrate the stored value's label by fetching it individually
+  useEffect(() => {
+    if (!fetchOptionById || isPreview || disabled) return
+
+    const valueToHydrate = value as string | null | undefined
+    if (!valueToHydrate) return
+
+    // Skip if value is an expression (not a real ID)
+    if (valueToHydrate.startsWith('<') || valueToHydrate.includes('{{')) return
+
+    // Skip if already hydrated with the same value
+    if (hydratedOption?.id === valueToHydrate) return
+
+    // Skip if value is already in fetched options or static options
+    const alreadyInFetchedOptions = fetchedOptions.some((opt) => opt.id === valueToHydrate)
+    const alreadyInStaticOptions = staticOptions.some((opt) =>
+      typeof opt === 'string' ? opt === valueToHydrate : opt.id === valueToHydrate
+    )
+    if (alreadyInFetchedOptions || alreadyInStaticOptions) return
+
+    // Track if effect is still active (cleanup on unmount or value change)
+    let isActive = true
+
+    // Fetch the hydrated option
+    fetchOptionById(blockId, subBlockId, valueToHydrate)
+      .then((option) => {
+        if (isActive) setHydratedOption(option)
+      })
+      .catch(() => {
+        if (isActive) setHydratedOption(null)
+      })
+
+    return () => {
+      isActive = false
+    }
+  }, [
+    fetchOptionById,
+    value,
+    blockId,
+    subBlockId,
+    isPreview,
+    disabled,
+    fetchedOptions,
+    staticOptions,
+    hydratedOption?.id,
+  ])
+
   /**
    * Handles wheel event for ReactFlow zoom control
    * Intercepts Ctrl/Cmd+Wheel to zoom the canvas
@@ -247,11 +417,13 @@ export function ComboBox({
             return option.id === newValue
           })
 
-          if (!matchedOption) {
+          // If a matching option is found, store its ID; otherwise store the raw value
-            return
+          // (allows expressions like <block.output> to be entered directly)
-          }
+          const nextValue = matchedOption
-
+            ? typeof matchedOption === 'string'
-          const nextValue = typeof matchedOption === 'string' ? matchedOption : matchedOption.id
+              ? matchedOption
+              : matchedOption.id
+            : newValue
           setStoreValue(nextValue)
         }}
         isPreview={isPreview}
@@ -293,6 +465,13 @@ export function ComboBox({
               onWheel: handleWheel,
               autoComplete: 'off',
             }}
+            isLoading={isLoadingOptions}
+            error={fetchError}
+            onOpenChange={(open) => {
+              if (open) {
+                void fetchOptionsIfNeeded()
+              }
+            }}
           />
         )}
       </SubBlockInputController>

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/dropdown/dropdown.tsx

@@ -44,6 +44,12 @@ interface DropdownProps {
     blockId: string,
     subBlockId: string
   ) => Promise<Array<{ label: string; id: string }>>
+  /** Async function to fetch a single option's label by ID (for hydration) */
+  fetchOptionById?: (
+    blockId: string,
+    subBlockId: string,
+    optionId: string
+  ) => Promise<{ label: string; id: string } | null>
   /** Field dependencies that trigger option refetch when changed */
   dependsOn?: SubBlockConfig['dependsOn']
   /** Enable search input in dropdown */
@@ -71,6 +77,7 @@ export function Dropdown({
   placeholder = 'Select an option...',
   multiSelect = false,
   fetchOptions,
+  fetchOptionById,
   dependsOn,
   searchable = false,
 }: DropdownProps) {
@@ -98,6 +105,7 @@ export function Dropdown({
   const [fetchedOptions, setFetchedOptions] = useState<Array<{ label: string; id: string }>>([])
   const [isLoadingOptions, setIsLoadingOptions] = useState(false)
   const [fetchError, setFetchError] = useState<string | null>(null)
+  const [hydratedOption, setHydratedOption] = useState<{ label: string; id: string } | null>(null)
 
   const previousModeRef = useRef<string | null>(null)
   const previousDependencyValuesRef = useRef<string>('')
@@ -150,11 +158,23 @@ export function Dropdown({
   }, [fetchedOptions])
 
   const availableOptions = useMemo(() => {
-    if (fetchOptions && normalizedFetchedOptions.length > 0) {
+    let opts: DropdownOption[] =
-      return normalizedFetchedOptions
+      fetchOptions && normalizedFetchedOptions.length > 0
+        ? normalizedFetchedOptions
+        : evaluatedOptions
+
+    // Merge hydrated option if not already present
+    if (hydratedOption) {
+      const alreadyPresent = opts.some((o) =>
+        typeof o === 'string' ? o === hydratedOption.id : o.id === hydratedOption.id
+      )
+      if (!alreadyPresent) {
+        opts = [hydratedOption, ...opts]
+      }
     }
-    return evaluatedOptions
+
-  }, [fetchOptions, normalizedFetchedOptions, evaluatedOptions])
+    return opts
+  }, [fetchOptions, normalizedFetchedOptions, evaluatedOptions, hydratedOption])
 
   /**
    * Convert dropdown options to Combobox format
@@ -310,7 +330,7 @@ export function Dropdown({
   )
 
   /**
-   * Effect to clear fetched options when dependencies actually change
+   * Effect to clear fetched options and hydrated option when dependencies actually change
    * This ensures options are refetched with new dependency values (e.g., new credentials)
    */
   useEffect(() => {
@@ -323,6 +343,7 @@ export function Dropdown({
         currentDependencyValuesStr !== previousDependencyValuesStr
       ) {
         setFetchedOptions([])
+        setHydratedOption(null)
       }
 
       previousDependencyValuesRef.current = currentDependencyValuesStr
@@ -338,18 +359,72 @@ export function Dropdown({
       !isPreview &&
       !disabled &&
       fetchedOptions.length === 0 &&
-      !isLoadingOptions
+      !isLoadingOptions &&
+      !fetchError
     ) {
       fetchOptionsIfNeeded()
     }
+    // eslint-disable-next-line react-hooks/exhaustive-deps -- fetchOptionsIfNeeded deps already covered above
   }, [
     fetchOptions,
     isPreview,
     disabled,
     fetchedOptions.length,
     isLoadingOptions,
-    fetchOptionsIfNeeded,
+    fetchError,
-    dependencyValues, // Refetch when dependencies change
+    dependencyValues,
+  ])
+
+  /**
+   * Effect to hydrate the stored value's label by fetching it individually
+   * This ensures the correct label is shown before the full options list loads
+   */
+  useEffect(() => {
+    if (!fetchOptionById || isPreview || disabled) return
+
+    // Get the value to hydrate (single value only, not multi-select)
+    const valueToHydrate = multiSelect ? null : (singleValue as string | null | undefined)
+    if (!valueToHydrate) return
+
+    // Skip if value is an expression (not a real ID)
+    if (valueToHydrate.startsWith('<') || valueToHydrate.includes('{{')) return
+
+    // Skip if already hydrated with the same value
+    if (hydratedOption?.id === valueToHydrate) return
+
+    // Skip if value is already in fetched options or static options
+    const alreadyInFetchedOptions = fetchedOptions.some((opt) => opt.id === valueToHydrate)
+    const alreadyInStaticOptions = evaluatedOptions.some((opt) =>
+      typeof opt === 'string' ? opt === valueToHydrate : opt.id === valueToHydrate
+    )
+    if (alreadyInFetchedOptions || alreadyInStaticOptions) return
+
+    // Track if effect is still active (cleanup on unmount or value change)
+    let isActive = true
+
+    // Fetch the hydrated option
+    fetchOptionById(blockId, subBlockId, valueToHydrate)
+      .then((option) => {
+        if (isActive) setHydratedOption(option)
+      })
+      .catch(() => {
+        if (isActive) setHydratedOption(null)
+      })
+
+    return () => {
+      isActive = false
+    }
+  }, [
+    fetchOptionById,
+    singleValue,
+    multiSelect,
+    blockId,
+    subBlockId,
+    isPreview,
+    disabled,
+    fetchedOptions,
+    evaluatedOptions,
+    hydratedOption?.id,
   ])
 
   /**

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/sub-block.tsx

@@ -460,6 +460,7 @@ function SubBlockComponent({
               disabled={isDisabled}
               multiSelect={config.multiSelect}
               fetchOptions={config.fetchOptions}
+              fetchOptionById={config.fetchOptionById}
               dependsOn={config.dependsOn}
               searchable={config.searchable}
             />
@@ -479,6 +480,9 @@ function SubBlockComponent({
               previewValue={previewValue as any}
               disabled={isDisabled}
               config={config}
+              fetchOptions={config.fetchOptions}
+              fetchOptionById={config.fetchOptionById}
+              dependsOn={config.dependsOn}
             />
           </div>
         )

apps/sim/blocks/types.ts

@@ -289,11 +289,19 @@ export interface SubBlockConfig {
   useWebhookUrl?: boolean
   // Trigger-save specific: The trigger ID for validation and saving
   triggerId?: string
-  // Dropdown specific: Function to fetch options dynamically (for multi-select or single-select)
+  // Dropdown/Combobox: Function to fetch options dynamically
+  // Works with both 'dropdown' (select-only) and 'combobox' (editable with expression support)
   fetchOptions?: (
     blockId: string,
     subBlockId: string
   ) => Promise<Array<{ label: string; id: string }>>
+  // Dropdown/Combobox: Function to fetch a single option's label by ID (for hydration)
+  // Called when component mounts with a stored value to display the correct label before options load
+  fetchOptionById?: (
+    blockId: string,
+    subBlockId: string,
+    optionId: string
+  ) => Promise<{ label: string; id: string } | null>
 }
 
 export interface BlockConfig<T extends ToolResponse = ToolResponse> {