Class AcDbLayerTable

Symbol table for layer table records.

This class manages layer table records which represent layers within a drawing database. Layers are used to organize and control the display of entities in the drawing. Each layer can have its own color, linetype, visibility settings, and other properties.

Example

const layerTable = new AcDbLayerTable(database);
const layer = layerTable.getAt('0');
const newLayer = new AcDbLayerTableRecord({ name: 'MyLayer' });
layerTable.add(newLayer);

Hierarchy (View Summary)

AcDbSymbolTable<AcDbLayerTableRecord>
- AcDbLayerTable

Index

Constructors

constructor

new AcDbLayerTable(db: AcDbDatabase): AcDbLayerTable
Creates a new AcDbLayerTable instance.

This constructor automatically creates a default layer named '0' with white color and continuous linetype.
Parameters
- db: AcDbDatabase
  The database this layer table belongs to
Returns AcDbLayerTable
Example
```
const layerTable = new AcDbLayerTable(database);
```
Overrides AcDbSymbolTable.constructor
- Defined in data-model/src/database/AcDbLayerTable.ts:39

Properties

`Protected`_recordsById

_recordsById: Map<string, AcDbLayerTableRecord>

Map of records indexed by object ID

`Protected`_recordsByName

_recordsByName: Map<string, AcDbLayerTableRecord>

Map of records indexed by name

Accessors

attrs

get attrs(): AcCmObject<ATTRS>
Gets the attributes object for this AcDbObject.

Returns AcCmObject<ATTRS>
The AcCmObject instance containing all attributes
Example
```
const attrs = obj.attrs;
const value = attrs.get('someAttribute');
```
Inherited from AcDbSymbolTable.attrs
- Defined in data-model/src/base/AcDbObject.ts:90

database

get database(): AcDbDatabase
Gets the database in which this object is resident.

When an object isn't added to a database, this property returns the current working database. After it is added to a database, it will be set automatically. You should never set this value manually.

Returns AcDbDatabase
The database this object belongs to
Example
```
const db = obj.database;
```
Inherited from AcDbSymbolTable.database
- Defined in data-model/src/base/AcDbObject.ts:273
set database(db: AcDbDatabase): void
Sets the database for this object.

This is typically set automatically when the object is added to a database. Manual setting should be avoided unless you know what you're doing.
Parameters
- db: AcDbDatabase
  The database to associate with this object
Returns void
Example
```
obj.database = myDatabase;
```
Inherited from AcDbSymbolTable.database
- Defined in data-model/src/base/AcDbObject.ts:292

extensionDictionary

get extensionDictionary(): undefined | string
Gets the objectId of the extension dictionary owned by this object.

If the object does not have an extension dictionary, this returns undefined.

In ObjectARX terms, this is equivalent to AcDbObject::extensionDictionary().

Returns undefined | string
The extension dictionary objectId, or undefined
Example
```
const dictId = obj.extensionDictionary
if (dictId) {
  console.log('Has extension dictionary:', dictId)
}
```
Inherited from AcDbSymbolTable.extensionDictionary
- Defined in data-model/src/base/AcDbObject.ts:236
set extensionDictionary(value: undefined | string): void
Sets the objectId of the extension dictionary owned by this object.

This does not create or delete the dictionary object itself — it only establishes or clears the ownership relationship.

Passing undefined removes the association.
Parameters
- value: undefined | string
  The extension dictionary objectId, or undefined
Returns void
Example
```
obj.extensionDictionary = dict.objectId
```
Inherited from AcDbSymbolTable.extensionDictionary
- Defined in data-model/src/base/AcDbObject.ts:255

numEntries

get numEntries(): number
Gets the number of entries in the table.

Returns number
The number of entries in the table
Inherited from AcDbSymbolTable.numEntries
- Defined in data-model/src/database/AcDbSymbolTable.ts:54

objectId

get objectId(): string
Gets the object ID.

AutoCAD uses 64-bit integers to represent handles, which exceed the maximum integer value of JavaScript. Therefore, strings are used to represent object handles.

Returns string
The object ID as a string
Example
```
const id = obj.objectId;
console.log(`Object ID: ${id}`);
```
Inherited from AcDbSymbolTable.objectId
- Defined in data-model/src/base/AcDbObject.ts:173
set objectId(value: string): void
Sets the object ID.
Parameters
- value: string
  The new object ID
Returns void
Example
```
obj.objectId = 'new-object-id';
```
Inherited from AcDbSymbolTable.objectId
- Defined in data-model/src/base/AcDbObject.ts:187

ownerId

get ownerId(): string
Gets the object ID of the owner of this object.

Returns string
The owner object ID
Example
```
const ownerId = obj.ownerId;
```
Inherited from AcDbSymbolTable.ownerId
- Defined in data-model/src/base/AcDbObject.ts:201
set ownerId(value: string): void
Sets the object ID of the owner of this object.
Parameters
- value: string
  The new owner object ID
Returns void
Example
```
obj.ownerId = 'parent-object-id';
```
Inherited from AcDbSymbolTable.ownerId
- Defined in data-model/src/base/AcDbObject.ts:215

Methods

add

add(record: AcDbLayerTableRecord): void
Adds a layer table record to this layer table.

This method overrides the base class method to dispatch a layerAppended event when a new layer is added to the table.
Parameters
- record: AcDbLayerTableRecord
  The layer table record to add
Returns void
Example
```
const newLayer = new AcDbLayerTableRecord({ name: 'MyLayer' });
layerTable.add(newLayer);
```
Overrides AcDbSymbolTable.add
- Defined in data-model/src/database/AcDbLayerTable.ts:69

close

close(): void
Closes the object.

All changes made to the object since it was opened are committed to the database, and a "closed" notification is sent. This method can be overridden by subclasses to provide specific cleanup behavior.

Returns void
Example
```
obj.close();
```
Inherited from AcDbSymbolTable.close
- Defined in data-model/src/base/AcDbObject.ts:429

createExtensionDictionary

createExtensionDictionary(): undefined | string
Creates the extension dictionary for this object if it does not already exist.

This method closely mirrors the behavior of AcDbObject::createExtensionDictionary() in ObjectARX.
- If the object already owns an extension dictionary, no new dictionary is created and the existing dictionary's objectId is returned.
- Otherwise, a new AcDbDictionary is created, added to the same database, owned by this object, and its objectId is stored on this object.
Returns undefined | string
The objectId of the extension dictionary
Example
```
const dictId = obj.createExtensionDictionary()
```
Inherited from AcDbSymbolTable.createExtensionDictionary
- Defined in data-model/src/base/AcDbObject.ts:392

getAt

getAt(name: string): undefined | AcDbLayerTableRecord
Searches the table for a record with the specified name.
Parameters
- name: string
  The name to search for
Returns undefined | AcDbLayerTableRecord
The record with the specified name, or undefined if not found
Example
```
const record = symbolTable.getAt('MyRecord');
if (record) {
  console.log('Found record:', record.name);
}
```
Inherited from AcDbSymbolTable.getAt
- Defined in data-model/src/database/AcDbSymbolTable.ts:188

getAttr

getAttr(attrName: string): any
Gets the value of the specified attribute.

This method will throw an exception if the specified attribute doesn't exist. Use getAttrWithoutException() if you want to handle missing attributes gracefully.
Parameters
- attrName: string
  The name of the attribute to retrieve
Returns any
The value of the specified attribute
Throws
When the specified attribute doesn't exist
Example
```
try {
  const value = obj.getAttr('objectId');
} catch (error) {
  console.error('Attribute not found');
}
```
Inherited from AcDbSymbolTable.getAttr
- Defined in data-model/src/base/AcDbObject.ts:113

getAttrWithoutException

getAttrWithoutException(attrName: string): any
Gets the value of the specified attribute without throwing an exception.

This method returns undefined if the specified attribute doesn't exist, making it safer for optional attributes.
Parameters
- attrName: string
  The name of the attribute to retrieve
Returns any
The value of the specified attribute, or undefined if it doesn't exist
Example
```
const value = obj.getAttrWithoutException('optionalAttribute');
if (value !== undefined) {
  // Use the value
}
```
Inherited from AcDbSymbolTable.getAttrWithoutException
- Defined in data-model/src/base/AcDbObject.ts:140

getIdAt

getIdAt(id: string): undefined | AcDbLayerTableRecord
Searches the table for a record with the specified ID.
Parameters
- id: string
  The ID to search for
Returns undefined | AcDbLayerTableRecord
The record with the specified ID, or undefined if not found
Example
```
const record = symbolTable.getIdAt('some-object-id');
if (record) {
  console.log('Found record:', record.name);
}
```
Inherited from AcDbSymbolTable.getIdAt
- Defined in data-model/src/database/AcDbSymbolTable.ts:207

getOwnerIdAt

getOwnerIdAt(id: string): undefined | AcDbLayerTableRecord
Gets the owner ID of a record with the specified ID.
Parameters
- id: string
  The ID to search for
Returns undefined | AcDbLayerTableRecord
The record with the specified ID, or undefined if not found
Example
```
const record = symbolTable.getOwnerIdAt('some-object-id');
if (record) {
  console.log('Owner ID:', record.ownerId);
}
```
Inherited from AcDbSymbolTable.getOwnerIdAt
- Defined in data-model/src/database/AcDbSymbolTable.ts:225

getXData

getXData(appId: string): undefined | AcDbResultBuffer
Retrieves the XData associated with this object for a given application ID.

Extended Entity Data (XData) allows applications to attach arbitrary, application-specific data to an AcDbObject. Each XData entry is identified by a registered application name (AppId) and stored as an AcDbResultBuffer.

This method is conceptually equivalent to AcDbObject::xData() in ObjectARX, but simplified to return the entire result buffer for the specified AppId.
Parameters
- appId: string
  The application ID (registered AppId name) that owns the XData
Returns undefined | AcDbResultBuffer
The AcDbResultBuffer associated with the AppId, or undefined if no XData exists for that AppId
Example
```
const xdata = obj.getXData('MY_APP')
if (xdata) {
  // Read values from the result buffer
}
```
Inherited from AcDbSymbolTable.getXData
- Defined in data-model/src/base/AcDbObject.ts:318

has

has(name: string): boolean
Checks if the table contains a record with the specified name.
Parameters
- name: string
  The name to search for
Returns boolean
True if a record with the specified name exists, false otherwise
Example
```
if (symbolTable.has('MyRecord')) {
  console.log('Record exists');
}
```
Inherited from AcDbSymbolTable.has
- Defined in data-model/src/database/AcDbSymbolTable.ts:152

hasId

hasId(id: string): boolean
Checks if the table contains a record with the specified ID.
Parameters
- id: string
  The ID to search for
Returns boolean
True if a record with the specified ID exists, false otherwise
Example
```
if (symbolTable.hasId('some-object-id')) {
  console.log('Record exists');
}
```
Inherited from AcDbSymbolTable.hasId
- Defined in data-model/src/database/AcDbSymbolTable.ts:170

newIterator

newIterator(): AcDbObjectIterator<AcDbLayerTableRecord>
Creates an iterator object that can be used to iterate over the records in the table.

Returns AcDbObjectIterator<AcDbLayerTableRecord>
An iterator object that can be used to iterate over the records
Example
```
const iterator = symbolTable.newIterator();
for (const record of iterator) {
  console.log('Record:', record.name);
}
```
Inherited from AcDbSymbolTable.newIterator
- Defined in data-model/src/database/AcDbSymbolTable.ts:242

`Protected`normalizeName

normalizeName(name: string): string
Normalizes the name of a symbol table record.

Some symbol table records require name normalization. For example, the model space block table record may appear as either *Model_Space or *MODEL_SPACE, and should be standardized to a consistent form.

Subclasses should override this method to implement record-specific normalization rules.
Parameters
- name: string
  The raw name of the symbol table record.
Returns string
The normalized symbol table record name.
Inherited from AcDbSymbolTable.normalizeName
- Defined in data-model/src/database/AcDbSymbolTable.ts:259

remove

remove(name: string): boolean
Removes the record with the specified name.
Parameters
- name: string
  The name of the record to remove
Returns boolean
True if the record was found and removed, false otherwise
Example
```
const removed = symbolTable.remove('MyRecord');
if (removed) {
  console.log('Record removed successfully');
}
```
Inherited from AcDbSymbolTable.remove
- Defined in data-model/src/database/AcDbSymbolTable.ts:90

removeAll

removeAll(): void
Removes all records from the table.

Returns void
Example
```
symbolTable.removeAll();
console.log('All records removed');
```
Inherited from AcDbSymbolTable.removeAll
- Defined in data-model/src/database/AcDbSymbolTable.ts:134

removeId

removeId(id: string): boolean
Removes the record with the specified ID.
Parameters
- id: string
  The object ID of the record to remove
Returns boolean
True if the record was found and removed, false otherwise
Example
```
const removed = symbolTable.removeId('some-object-id');
if (removed) {
  console.log('Record removed successfully');
}
```
Inherited from AcDbSymbolTable.removeId
- Defined in data-model/src/database/AcDbSymbolTable.ts:115

removeXData

removeXData(appId: string): void
Removes the XData associated with the specified application ID.

After removal, calls to getXData() for the same AppId will return undefined. If no XData exists for the given AppId, this method has no effect.

This mirrors the behavior of clearing XData for a specific application in ObjectARX rather than removing all XData from the object.
Parameters
- appId: string
  The application ID whose XData should be removed
Returns void
Example
```
obj.removeXData('MY_APP')
```
Inherited from AcDbSymbolTable.removeXData
- Defined in data-model/src/base/AcDbObject.ts:370

setAttr

setAttr<A extends string>(attrName: A, val?: AcDbObjectAttrs[A]): void
Sets the value of an attribute.
Type Parameters
- A extends string
Parameters
- attrName: A
  The name of the attribute to set
- Optionalval: AcDbObjectAttrs[A]
  The value to assign to the attribute
Returns void
Example
```
obj.setAttr('objectId', 'new-id-123');
```
Inherited from AcDbSymbolTable.setAttr
- Defined in data-model/src/base/AcDbObject.ts:155

setXData

setXData(resbuf: AcDbResultBuffer): void
Attaches or replaces XData for this object.

If XData already exists for the given AppId, it is replaced by the provided AcDbResultBuffer. The caller is responsible for ensuring that:
- The AppId is registered in the database's AppId table
- The result buffer follows valid DXF/XData conventions (e.g. starts with a 1001 group code for the AppId)
This method is conceptually similar to AcDbObject::setXData() in ObjectARX.
Parameters
- resbuf: AcDbResultBuffer
  The result buffer containing the XData to attach
Returns void
Example
```
const rb = new AcDbResultBuffer([
  { code: AcDbDxfCode.ExtendedDataRegAppName, value: 'MY_APP' },
  { code: AcDbDxfCode.ExtendedDataAsciiString, value: 'custom value' }
])

obj.setXData('MY_APP', rb)
```
Inherited from AcDbSymbolTable.setXData
- Defined in data-model/src/base/AcDbObject.ts:346

Class AcDbLayerTable

Example

Hierarchy (View Summary)

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

Returns AcDbLayerTable

Example

Properties

Protected_recordsById

Protected_recordsByName

Accessors

attrs

Returns AcCmObject<ATTRS>

Example

database

Returns AcDbDatabase

Example

Parameters

Returns void

Example

extensionDictionary

Returns undefined | string

Example

Parameters

Returns void

Example

numEntries

Returns number

objectId

Returns string

Example

Parameters

Returns void

Example

ownerId

Returns string

Example

Parameters

Returns void

Example

Methods

add

Parameters

Returns void

Example

close

Returns void

Example

createExtensionDictionary

Returns undefined | string

Example

getAt

Parameters

Returns undefined | AcDbLayerTableRecord

Example

getAttr

Parameters

Returns any

Throws

Example

getAttrWithoutException

Parameters

Returns any

Example

getIdAt

Parameters

Returns undefined | AcDbLayerTableRecord

Example

getOwnerIdAt

Parameters

Returns undefined | AcDbLayerTableRecord

Example

getXData

Parameters

`Protected`_recordsById

`Protected`_recordsByName

`Protected`normalizeName