Context

java.lang.Object
- org.basex.core.Context

```
public final class Context
extends java.lang.Object
```
This class serves as a central database context. It references the currently opened database. Moreover, it provides references to the currently used, marked and copied node sets. This class should only be instantiated once in a project; otherwise, database updates may lead to conflicts.

Author:

BaseX Team 2005-12, BSD License, Christian Gruen

Field Summary

Fields
Modifier and Type	Field and Description
`Nodes`	`copied` Copied nodes.
`Datas`	`datas` Database pool.
`Events`	`events` Event pool.
`int`	`focused` Focused node.
`ClientListener`	`listener` Client listener.
`Nodes`	`marked` Marked nodes.
`MainProp`	`mprop` Main properties.
`Prop`	`prop` Client-related properties.
`Repo`	`repo` Package repository.
`Sessions`	`sessions` Client connections.
`User`	`user` User reference.
`Users`	`users` Users.

Constructor Summary

Constructors
Constructor and Description
`Context()` Default constructor, which should only be called once in a project.
`Context(Context ctx, ClientListener cl)` Constructor, passing on the main context.
`Context(java.util.HashMap<java.lang.String,java.lang.String> props)` Default constructor, which should only be called once in a project.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(ClientListener s)` Adds the specified client session.
`boolean`	`client()` Returns `true` if the current context belongs to a client user.
`void`	`close()` Closes the database context.
`void`	`closeDB()` Resets the current database context.
`Nodes`	`current()` Returns the current node context.
`void`	`current(Nodes curr)` Sets the current node context.
`Data`	`data()` Returns the current data reference.
`Databases`	`databases()` Get list of currently available databases.
`void`	`delete(ClientListener s)` Removes the specified client session.
`void`	`openDB(Data d)` Sets the specified data instance as current database.
`void`	`openDB(Data d, java.lang.String p)` Sets the specified data instance as current database and restricts the context nodes to the given path.
`boolean`	`perm(int p, MetaData md)` Checks if the current user has the specified permission.
`void`	`pin(Data d)` Adds the specified data reference to the pool.
`Data`	`pin(java.lang.String name)` Pins and returns an existing data reference for the specified database, or returns `null`.
`boolean`	`pinned(java.lang.String db)` Checks if the specified database is pinned.
`void`	`register(Progress pr)` Locks a writing process and starts the timeout.
`boolean`	`root()` Returns `true` if the current node set contains all documents.
`void`	`set(Nodes curr, Nodes mark)` Sets the current context and marked node set and resets the focus.
`boolean`	`unpin(Data d)` Unpins a data reference.
`void`	`unregister(Progress pr)` Unlocks the process and stops the timeout.
`void`	`update()` Invalidates the current node set.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - listener
```
public final ClientListener listener
```
    Client listener. Set to null in standalone/server mode.
  - prop
```
public final Prop prop
```
    Client-related properties.
  - mprop
```
public final MainProp mprop
```
    Main properties.
  - sessions
```
public final Sessions sessions
```
    Client connections.
  - events
```
public final Events events
```
    Event pool.
  - datas
```
public final Datas datas
```
    Database pool.
  - users
```
public final Users users
```
    Users.
  - repo
```
public final Repo repo
```
    Package repository.
  - user
```
public User user
```
    User reference.
  - marked
```
public Nodes marked
```
    Marked nodes.
  - copied
```
public Nodes copied
```
    Copied nodes.
  - focused
```
public int focused
```
    Focused node.
- Constructor Detail
  - Context
```
public Context()
```
    Default constructor, which should only be called once in a project.
  - Context
```
public Context(java.util.HashMap<java.lang.String,java.lang.String> props)
```
    Default constructor, which should only be called once in a project.
    
    Parameters:
    props - initial properties
  - Context
```
public Context(Context ctx,
       ClientListener cl)
```
    Constructor, passing on the main context. The user reference must be set after calling this method.
    
    Parameters:
    ctx - parent database context
    cl - client listener
- Method Detail
  - close
```
public void close()
```
    Closes the database context.
  - client
```
public boolean client()
```
    Returns true if the current context belongs to a client user.
    
    Returns:
    result of check
  - root
```
public boolean root()
```
    Returns true if the current node set contains all documents.
    
    Returns:
    result of check
  - data
```
public Data data()
```
    Returns the current data reference.
    
    Returns:
    data reference
  - current
```
public Nodes current()
```
    Returns the current node context.
    
    Returns:
    node set
  - current
```
public void current(Nodes curr)
```
    Sets the current node context.
    
    Parameters:
    curr - node set
  - openDB
```
public void openDB(Data d)
```
    Sets the specified data instance as current database.
    
    Parameters:
    d - data reference
  - openDB
```
public void openDB(Data d,
          java.lang.String p)
```
    Sets the specified data instance as current database and restricts the context nodes to the given path.
    
    Parameters:
    d - data reference
    p - database path
  - closeDB
```
public void closeDB()
```
    Resets the current database context.
  - set
```
public void set(Nodes curr,
       Nodes mark)
```
    Sets the current context and marked node set and resets the focus.
    
    Parameters:
    curr - context set
    mark - marked nodes
  - update
```
public void update()
```
    Invalidates the current node set.
  - pin
```
public void pin(Data d)
```
    Adds the specified data reference to the pool.
    
    Parameters:
    d - data reference
  - pin
```
public Data pin(java.lang.String name)
```
    Pins and returns an existing data reference for the specified database, or returns null.
    
    Parameters:
    name - name of database
    
    Returns:
    data reference
  - unpin
```
public boolean unpin(Data d)
```
    Unpins a data reference.
    
    Parameters:
    d - data reference
    
    Returns:
    true if reference was removed from the pool
  - pinned
```
public boolean pinned(java.lang.String db)
```
    Checks if the specified database is pinned.
    
    Parameters:
    db - name of database
    
    Returns:
    result of check
  - register
```
public void register(Progress pr)
```
    Locks a writing process and starts the timeout.
    
    Parameters:
    pr - process
  - unregister
```
public void unregister(Progress pr)
```
    Unlocks the process and stops the timeout.
    
    Parameters:
    pr - process
  - add
```
public void add(ClientListener s)
```
    Adds the specified client session.
    
    Parameters:
    s - session to be added
  - delete
```
public void delete(ClientListener s)
```
    Removes the specified client session.
    
    Parameters:
    s - session to be removed
  - perm
```
public boolean perm(int p,
           MetaData md)
```
    Checks if the current user has the specified permission.
    
    Parameters:
    p - requested permission
    md - optional meta data reference
    
    Returns:
    result of check
  - databases
```
public Databases databases()
```
    Get list of currently available databases.
    
    Returns:
    the databases

Class Context

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

listener

prop

mprop

sessions

events

datas

users

repo

user

marked

copied

focused

Constructor Detail

Context

Context

Context

Method Detail

close

client

root

data

current

current

openDB

openDB

closeDB

set

update

pin

pin

unpin

pinned

register

unregister

add

delete

perm

databases