Package io.pebbletemplates.pebble.template

Class ScopeChain

java.lang.Object
io.pebbletemplates.pebble.template.ScopeChain
public class ScopeChain extends Object
A stack data structure used to represent the scope of variables that are currently accessible. Pushing a new scope will allow the template to add variables with names of pre-existing variables without overriding the originals; to access the original variables you would pop the scope again.

  • Constructor Summary

    Constructors
    Constructor
    Description
    ScopeChain()
    Constructs an empty scope chain without any known scopes.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    containsKey(String key)
    This method checks if the given key does exists within the scope chain.
    boolean
    currentScopeContainsVariable(String variableName)
    Checks if the current scope contains a variable without then looking up the scope chain.
    ScopeChain
    deepCopy()
    Creates a deep copy of the ScopeChain.
    Object
    get(String key)
    Retrieves a variable from the scope chain, starting at the current scope and working it's way up all visible scopes.
    List<Scope>
    getGlobalScopes()
     
    void
    popScope()
    Pops the most recent scope from the scope chain.
    void
    pushLocalScope()
    Adds a new local scope to the scope chain
    void
    pushScope()
    Adds an empty non-local scope to the scope chain
    void
    pushScope(Map<String,Object> map)
    Adds a new non-local scope to the scope chain
    void
    put(String key, Object value)
    Adds a variable to the current scope.
    void
    set(String key, Object value)
    Sets the value of a variable in the first scope in the chain that already contains the variable; adds a variable to the current scope if an existing variable is not found.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • ScopeChain

      public ScopeChain()
      Constructs an empty scope chain without any known scopes.

  • Method Details

    • deepCopy

      public ScopeChain deepCopy()
      Creates a deep copy of the ScopeChain. This is used for the parallel tag because every new thread should have a "snapshot" of the scopes, i.e. if one thread adds a new object to a scope, it should not be available to the other threads.

      This will construct a new scope chain and new scopes but it will continue to have references to the original user-provided variables. This is why it is important for the user to only provide thread-safe variables when using the "parallel" tag.

      Returns:
      A copy of the scope chain

    • pushScope

      public void pushScope()
      Adds an empty non-local scope to the scope chain

    • pushScope

      public void pushScope(Map<String,Object> map)
      Adds a new non-local scope to the scope chain
      Parameters:
      map - The known variables of this scope.

    • pushLocalScope

      public void pushLocalScope()
      Adds a new local scope to the scope chain

    • popScope

      public void popScope()
      Pops the most recent scope from the scope chain.

    • put

      public void put(String key, Object value)
      Adds a variable to the current scope.
      Parameters:
      key - The name of the variable
      value - The value of the variable

    • get

      public Object get(String key)
      Retrieves a variable from the scope chain, starting at the current scope and working it's way up all visible scopes.
      Parameters:
      key - The name of the variable
      Returns:
      The value of the variable

    • containsKey

      public boolean containsKey(String key)
      This method checks if the given key does exists within the scope chain.
      Parameters:
      key - the for which the the check should be executed for.
      Returns:
      true when the key does exists or false when the given key does not exists.

    • currentScopeContainsVariable

      public boolean currentScopeContainsVariable(String variableName)
      Checks if the current scope contains a variable without then looking up the scope chain.
      Parameters:
      variableName - The name of the variable
      Returns:
      Whether or not the variable exists in the current scope

    • set

      public void set(String key, Object value)
      Sets the value of a variable in the first scope in the chain that already contains the variable; adds a variable to the current scope if an existing variable is not found.
      Parameters:
      key - The name of the variable
      value - The value of the variable

    • getGlobalScopes

      public List<Scope> getGlobalScopes()