---
title: "ctx.collectionField"
description: "The collection field (CollectionField) instance for the current RunJS context; used to access field metadata, type, validation rules, and association info. Only present when the field is bound to a collection definition; custom/virtual fields may have `null`."
---

# ctx.collectionField

The collection field (CollectionField) instance for the current RunJS context; used to access field metadata, type, validation rules, and association info. Only present when the field is bound to a collection definition; custom/virtual fields may have `null`.

## Use Cases

| Scenario | Description |
|----------|-------------|
| **JSField** | Use `interface`, `enum`, `targetCollection`, etc. for linkage or validation |
| **JSItem** | Access metadata of the column’s field in sub-table items |
| **JSColumn** | Choose render by `collectionField.interface`, or use `targetCollection` |

> Note: `ctx.collectionField` is only available when the field is bound to a collection; in standalone JSBlock or actions with no field binding it is usually `undefined`—check before use.

## Common Properties

| Property | Type | Description |
|----------|------|-------------|
| `name` | `string` | Field name (e.g. `status`, `userId`) |
| `title` | `string` | Field title (i18n) |
| `type` | `string` | Data type (`string`, `integer`, `belongsTo`, etc.) |
| `interface` | `string` | UI type (`input`, `select`, `m2o`, `o2m`, `m2m`, etc.) |
| `collection` | `Collection` | Field’s collection |
| `targetCollection` | `Collection` | Target collection for association fields only |
| `target` | `string` | Target collection name (association) |
| `enum` | `array` | Enum options (select, radio, etc.) |
| `defaultValue` | `any` | Default value |
| `collectionName` | `string` | Collection name |
| `foreignKey` | `string` | Foreign key (e.g. belongsTo) |
| `sourceKey` | `string` | Source key (e.g. hasMany) |
| `targetKey` | `string` | Target key |
| `fullpath` | `string` | Full path (e.g. `main.users.status`) for API/variables |
| `resourceName` | `string` | Resource name (e.g. `users.status`) |
| `readonly` | `boolean` | Read-only |
| `titleable` | `boolean` | Can be used as title |
| `validation` | `object` | Validation config |
| `uiSchema` | `object` | UI config |
| `targetCollectionTitleField` | `CollectionField` | Title field of target collection (association) |

## Common Methods

| Method | Description |
|--------|-------------|
| `isAssociationField(): boolean` | Whether it is an association (belongsTo, hasMany, hasOne, belongsToMany, etc.) |
| `isRelationshipField(): boolean` | Whether it is a relationship (o2o, m2o, o2m, m2m, etc.) |
| `getComponentProps(): object` | Default props for the field component |
| `getFields(): CollectionField[]` | Fields of target collection (association only) |
| `getFilterOperators(): object[]` | Filter operators (e.g. `$eq`, `$ne`) |

## Examples

## Relation to ctx.collection

| Need | Recommended |
|------|-------------|
| **Collection of current field** | `ctx.collectionField?.collection` or `ctx.collection` |
| **Field metadata (name, type, interface, enum, etc.)** | `ctx.collectionField` |
| **Target collection** | `ctx.collectionField?.targetCollection` |

`ctx.collection` is usually the block’s collection; `ctx.collectionField` is the field definition; they can differ in sub-tables and associations.

## Notes

- In **JSBlock**, **JSAction (no field binding)**, `ctx.collectionField` is usually `undefined`; use optional chaining.
- Custom JS fields not bound to a collection field may have `ctx.collectionField` as `null`.
- `targetCollection` exists only for association fields (m2o, o2m, m2m); `enum` only for select, radioGroup, etc.

## Related

- [ctx.collection](/runjs/context/collection.md): collection for current context
- [ctx.model](/runjs/context/model.md): model for current execution context
- [ctx.blockModel](/runjs/context/block-model.md): parent block
- [ctx.getValue()](/runjs/context/get-value.md), [ctx.setValue()](/runjs/context/set-value.md): read/write current field value

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## Extracted references

- **Type Example** (`runjs/context/collection-field__example-1.md`) - Extracted example from ctx.collectionField
- **Branch by field type Example** (`runjs/context/collection-field__example-2.md`) - Extracted example from ctx.collectionField
- **Check association and use target collection Example** (`runjs/context/collection-field__example-3.md`) - Extracted example from ctx.collectionField
- **Get enum options Example** (`runjs/context/collection-field__example-4.md`) - Extracted example from ctx.collectionField
- **Conditional render by readonly Example** (`runjs/context/collection-field__example-5.md`) - Extracted example from ctx.collectionField
- **Title field of target collection Example** (`runjs/context/collection-field__example-6.md`) - Extracted example from ctx.collectionField

<!-- docs:splits:end -->