All Known Subinterfaces:

WebLimitExpressionHelper

All Known Implementing Classes:

RWViewLimitHelper, WebMDXExpressionHelper, WebMDXReportLimitHelper, WebSubsetViewLimitHelper
```
public interface WebExpressionHelper
```
The WebExpressionHelper interface is a helper interface which is used to manipulate the expression tree with multi-step, complex manipulations. All of these manipulations can be done by using the WebExpression/WebNode interfaces, but this class simplifies the performance of many of those operations. This object can be obtained from a WebExpression instance, and is linked to that instance.

Since:

MicroStrategy Web 7.3.1 or earlier

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`canEditExpression()`
`boolean`	`canGroup(int firstKey, int secondKey)`	Check whether it is possible to call group() on the two nodes with the given keys.
`boolean`	`canGroup(WebNode firstNode, WebNode secondNode)`	Check whether it is possible to call group() on the two given nodes.
`boolean`	`canSwapWithNext(int nodeKey)`	Checks whether it is possible to call swapWithNext() on the node with the given key.
`boolean`	`canSwapWithNext(WebNode node)`	Checks whether it is possible to call swapWithNext() on the given node.
`boolean`	`canSwapWithPrevious(int nodeKey)`	Checks whether it is possible to call swapWithPrevious() on the node with the given key.
`boolean`	`canSwapWithPrevious(WebNode node)`	Checks whether it is possible to call swapWithPrevious() on the given node.
`boolean`	`canUngroup(int firstKey, int secondKey)`	Check whether it is possible to call ungroup() on the two nodes with the given keys.
`boolean`	`canUngroup(WebNode firstNode, WebNode secondNode)`	Check whether it is possible to call ungroup() on the two given nodes.
`boolean`	`compareTo(WebExpression anotherExp)`	Compares two WebExpression.
`void`	`consolidateTree()`	Consolidates the whole expression tree.
`void`	`delete(int nodeKey)`	Delete the node with the given key from the expression.
`void`	`delete(WebNode node)`	Delete the specified node from the expression.
`boolean`	`getAutoConsolidation()`	Return the current setting for the auto-consolidation option.
`WebOperatorNode`	`getNewRootNode()`	Creates a new root node for the underlying `WebExpression`.
`WebNode`	`group(int firstKey, int secondKey)`	Group two nodes in the expression together.
`WebNode`	`group(WebNode firstNode, WebNode secondNode)`	Group two nodes in the expression together.
`boolean`	`hasFilterOn(WebObjectInfo oi)`	Returns whether the expression contains an qualification on specified object
`boolean`	`isEqual(WebNode n1, WebNode n2)`	Checks whether two WebNode are equal.
`WebExpression`	`removeEmptyFilters()`	This method will take the current expression tree and attempt to remove any empty filters in the expression.
`void`	`setAutoConsolidation(boolean auto)`	Sets the auto-consolidation option on this instance.
`void`	`swap(int firstKey, int secondKey)`	Swap two nodes in the expression.
`void`	`swap(WebNode firstNode, WebNode secondNode)`	Swap two nodes in the expression.
`void`	`swapWithNext(int nodeKey)`	Swaps the node with the given key with its next sibling.
`void`	`swapWithNext(WebNode node)`	Swaps the given node with its next sibling.
`void`	`swapWithPrevious(int nodeKey)`	Swaps the node with the given key with the previous sibling.
`void`	`swapWithPrevious(WebNode node)`	Swaps the given node with the previous sibling.
`void`	`toggleFunction(int firstKey, int secondKey, int toggleFunction)`	Change the function between the two nodes with the given keys to the specified function.
`void`	`toggleFunction(WebNode firstNode, WebNode secondNode, int toggleFunction)`	Change the function between the two given nodes to the specified function.
`void`	`ungroup(int firstKey, int secondKey)`	Ungroup two nodes in the expression.
`void`	`ungroup(WebNode firstNode, WebNode secondNode)`	Ungroup two nodes in the expression.
`boolean`	`validateOperands(WebNode node, RWDataSet ds)`	Returns whether the given node and its children are valid.

- Method Detail
  - getAutoConsolidation
```
boolean getAutoConsolidation()
```
    Return the current setting for the auto-consolidation option. When the auto-consolidation setting is on, a consolidation of the expression tree will be done after every other manipulation on this interface. See the consolidateTree method for the effects of a consolidation operation. By default, this option is true.
    
    Returns:
    
    The current setting for auto-consolidation.
    
    See Also:
    
    setAutoConsolidation(boolean), consolidateTree()
  - setAutoConsolidation
```
void setAutoConsolidation(boolean auto)
```
    Sets the auto-consolidation option on this instance. When the auto-consolidation setting is on, a consolidation of the expression tree will be done after every other manipulation on this interface. See the consolidateTree method for the effects of a consolidation operation.
    
    Parameters:
    
    auto - The desired setting for auto-consolidation.
    
    See Also:
    
    getAutoConsolidation(), consolidateTree()
  - consolidateTree
```
void consolidateTree()
```
    Consolidates the whole expression tree.
    Consolidation rules:
    Any branch qualification (AND, OR, or NOT) which has no child nodes will be removed.
    Branch qualifications (AND, OR), which have 1 child node will be removed and the tree adjusted such that the expression's meaning will not be changed.
    If a NOT node has a NOT node as it's child node, both not nodes will be removed.
    Any AND or OR node, can not have its first child as NOT node,
    If the first child is a NOT node,
    if there is at least one non-NOT child, try to swap with the first non-NOT child
    else, create a NOT node, move current AND or OR node under the NOT node, then change the AND to OR, OR to AND, then replace all NOT children with their children. Eg. (NOT A AND NOT B) -> NOT (A OR B)
    
    Note that this operation will be performed on the tree after every operation if the auto-consolidation setting is true.
  - removeEmptyFilters
```
WebExpression removeEmptyFilters()
```
    This method will take the current expression tree and attempt to remove any empty filters in the expression. After doing that, it will consolidate the new expression. This method, if it is necessary to change the expresssion, will return a copy of the current expression; the expression that belongs to this WebExpressionHelper object will never be modified.
    
    Returns:
    
    Either the current expression, if no change was needed, or a copy of the current expression that has empty filters removed and is consolidated.
    
    Since:
    
    MicroStrategy Web 7.5.4
  - group
```
WebNode group(WebNode firstNode,
              WebNode secondNode)
       throws java.lang.IllegalArgumentException,
              WebObjectsException
```
    Group two nodes in the expression together. The two nodes given must either share a parent node or for the first node and the parent node of the second child (which must be a NOT node) share a common parent node. In the second case, the operator will be considered to be the parent and the not node combined(i.e. AND NOT or OR NOT). This method will create a new node, which will have the same function (AND or OR) as the original parent of these two nodes. The new node is inserted at the position of the first given node, and the two given nodes will be set as child nodes of the newly created node.
    
    Parameters:
    
    firstNode - The first input parameter, which must share a parent with secondNode
    
    secondNode - The second input parameter, which must either share a parent with firstNode or the parent node must be a NOT node, and that node must share a parent with the firstNode.
    
    Returns:
    
    The new parent node of the two given nodes.
    
    Throws:
    
    WebObjectsException - Thrown when the parent of one child is not a branch qualification operator, when these children do not share the same parent, or when one of the input nodes is the root node of the expression.
    
    java.lang.IllegalArgumentException - Thrown if either input parameter is null.
  - group
```
WebNode group(int firstKey,
              int secondKey)
       throws java.lang.IllegalArgumentException,
              WebObjectsException
```
    Group two nodes in the expression together. This method is used to identify the nodes by the key of the expression. The two nodes given must either share a parent node or for the first node and the parent node of the second child (which must be a NOT node) share a common parent node. In the second case, the operator will be considered to be the parent and the not node combined(i.e. AND NOT or OR NOT). This method will create a new node, which will have the same function (AND or OR) as the original parent of these two nodes. The new node is inserted at the position of the first given node, and the two given nodes will be set as child nodes of the newly created node.
    
    Parameters:
    
    firstKey - The key of the first node.
    
    secondKey - The key of the second node. the parent node must be a NOT node, and that node must share a parent with the firstNode.
    
    Returns:
    
    The new parent node of the two given nodes.
    
    Throws:
    
    WebObjectsException - Thrown when the parent of one child is not a branch qualification operator, when these children do not share the same parent, or when one of the input nodes is the root node of the expression.
    
    java.lang.IllegalArgumentException - Thrown if either input parameter is null.
  - ungroup
```
void ungroup(WebNode firstNode,
             WebNode secondNode)
      throws java.lang.IllegalArgumentException,
             WebObjectsException
```
    Ungroup two nodes in the expression. The parent of both given nodes, which is an operator node, will be removed and the two child nodes will be moved to the removed node's position in the expression. The two nodes given must either share a parent node or for the first node and the parent node of the second child (which must be a NOT node) share a common parent node. In the second case, the operator will be considered to be the parent and the not node combined(i.e. AND NOT or OR NOT).
    
    Parameters:
    
    firstNode - The first node to be ungrouped.
    
    secondNode - The second node to be ungrouped.
    
    Throws:
    
    WebObjectsException - Thrown when parent node of one of the given nodes is not a branch qualificaiton operator, when the given nodes do not share the same parent, or when one of the input nodes or the parent of the input nodes is the root node of the expression.
    
    java.lang.IllegalArgumentException - Thrown when one of the input parameters is null.
  - ungroup
```
void ungroup(int firstKey,
             int secondKey)
      throws java.lang.IllegalArgumentException,
             WebObjectsException
```
    Ungroup two nodes in the expression. This method allows the user to specify the nodes to be ungrouped by their keys. The parent of both given nodes, which is an operator node, will be removed and the two child nodes will be moved to the removed node's position in the expression. The two nodes given must either share a parent node or for the first node and the parent node of the second child (which must be a NOT node) share a common parent node. In the second case, the operator will be considered to be the parent and the not node combined(i.e. AND NOT or OR NOT).
    
    Parameters:
    
    firstKey - The key of first node to be ungrouped.
    
    secondKey - The key of second node to be ungrouped.
    
    Throws:
    
    WebObjectsException - Thrown when parent node of one of the given nodes is not a branch qualificaiton operator, when the given nodes do not share the same parent, or when one of the input nodes or the parent of the input nodes is the root node of the expression.
    
    java.lang.IllegalArgumentException - Thrown when one of the input parameters is null.
  - swap
```
void swap(WebNode firstNode,
          WebNode secondNode)
   throws java.lang.IllegalArgumentException
```
    Swap two nodes in the expression. These two nodes can be anywhere in the expression tree. After calling this method, the two nodes' locations will be swapped.
    
    Parameters:
    
    firstNode - The first node to be swapped.
    
    secondNode - The second node to be swapped.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown when the input parameter is null.
  - swap
```
void swap(int firstKey,
          int secondKey)
   throws java.lang.IllegalArgumentException
```
    Swap two nodes in the expression. These two nodes can be anywhere in the expression tree. After calling this method, the two nodes' locations will be swapped.
    
    Parameters:
    
    firstKey - The key of the first node to be swapped.
    
    secondKey - The key of the second node to be swapped.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown when one of the keys do not exist in the expression tree.
  - swapWithPrevious
```
void swapWithPrevious(WebNode node)
               throws java.lang.IllegalArgumentException,
                      WebObjectsException
```
    Swaps the given node with the previous sibling. This only works if the given node is not the first child of it's parent node.
    There are two special cases:
    If the parent node is a NOT node, swap the given node with the NOT node's previous sibling.
    If the previous sibling is a NOT node, swap the given node with its child.
    Parameters:
    
    node - The node to be swapped.
    
    Throws:
    
    WebObjectsException - Thrown if the parent of the given node is not a branch qualification operator or when there is no previous sibling to swap with.
    
    java.lang.IllegalArgumentException - Thrown when the input parameter is null.
  - swapWithPrevious
```
void swapWithPrevious(int nodeKey)
               throws java.lang.IllegalArgumentException,
                      WebObjectsException
```
    Swaps the node with the given key with the previous sibling. This only works if the given node is not the first child of it's parent node.
    There are two special cases:
    If the parent node is a NOT node, swap the given node with the NOT node's previous sibling.
    If the previous sibling is a NOT node, swap the given node with its child.
    Parameters:
    
    nodeKey - The key of the node to be swapped.
    
    Throws:
    
    WebObjectsException - Thrown if the parent of the given node is not a branch qualification operator or when there is no previous sibling to swap with.
    
    java.lang.IllegalArgumentException - Thrown if no node with the given key exists.
  - swapWithNext
```
void swapWithNext(WebNode node)
           throws java.lang.IllegalArgumentException,
                  WebObjectsException
```
    Swaps the given node with its next sibling. This only works if the given node is not the last child of it's parent node.
    There are two special cases:
    If the parent node is a NOT node, swap the given node with the NOT node's next sibling.
    If the next sibling is a NOT node, swap the given node with its child.
    Parameters:
    
    node - The node to be swapped.
    
    Throws:
    
    WebObjectsException - Thrown if the parent of the given node is not a branch qualification operator or when there is no previous sibling to swap with.
    
    java.lang.IllegalArgumentException - Thrown when the input parameter is null.
  - swapWithNext
```
void swapWithNext(int nodeKey)
           throws java.lang.IllegalArgumentException,
                  WebObjectsException
```
    Swaps the node with the given key with its next sibling. This only works if the given node is not the last child of it's parent node.
    There are two special cases:
    If the parent node is a NOT node, swap the given node with the NOT node's next sibling.
    If the next sibling is a NOT node, swap the given node with its child.
    Parameters:
    
    nodeKey - The key of the node to be swapped.
    
    Throws:
    
    WebObjectsException - Thrown if the parent of the given node is not a branch qualification operator or when there is no previous sibling to swap with.
    
    java.lang.IllegalArgumentException - Thrown if no node with the given key exists.
  - toggleFunction
```
void toggleFunction(WebNode firstNode,
                    WebNode secondNode,
                    int toggleFunction)
             throws java.lang.IllegalArgumentException,
                    WebObjectsException
```
    Change the function between the two given nodes to the specified function. The functions which are available come from EnumWebToggleFunction. Note that if AND NOT or OR NOT are the original operator, the node directly under the NOT node should be specified as the second argument to this method. These two nodes either should be the direct children of the same parent, or the second node must have a NOT node as its parent which shares a parent with the first argument.
    For example, if there were an AND node, with children firstNode and a NOT node which has the secondNode as a child node, then the original function is considered to be AND NOT.
    
    Each time, this function will add a new node for the new toggleFunction first. Then if the auto consolidation is set, it may remove the original function node (the shared parent of the two input nodes).
    
    Parameters:
    
    firstNode - The first node whose parent operator will be toggled.
    
    secondNode - The second node whose parent operator will be toggled.
    
    toggleFunction - The function to toggle to, which is a value from EnumWebToggleFunction.
    
    Throws:
    
    WebObjectsException - Thrown if the parent of the given nodes is not aa branch qualification operator, the two given nodes do not share the same parent, or if either the first node, second node, or the shared parent node are the root node of the expression.
    
    java.lang.IllegalArgumentException - Thrown when input parameter is null.
    
    See Also:
    
    consolidateTree()
  - toggleFunction
```
void toggleFunction(int firstKey,
                    int secondKey,
                    int toggleFunction)
             throws java.lang.IllegalArgumentException,
                    WebObjectsException
```
    Change the function between the two nodes with the given keys to the specified function. The functions which are available come from EnumWebToggleFunction. Note that if AND NOT or OR NOT are the original operator, the node directly under the NOT node should be specified as the second argument to this method. These two nodes either should be the direct children of the same parent, or the second node must have a NOT node as its parent which shares a parent with the first argument.
    For example, if there were an AND node, with children firstNode and a NOT node which has the secondNode as a child node, then the original function is considered to be AND NOT.
    
    Each time, this function will add a new node for the new toggleFunction first. Then if the auto consolidation is set, it may remove the original function node (the shared parent of the two input nodes).
    
    Parameters:
    
    firstKey - The key of the first node whose parent operator will be toggled.
    
    secondKey - The key of the second node whose parent operator will be toggled.
    
    toggleFunction - The function to toggle to, which is a value from EnumWebToggleFunction.
    
    Throws:
    
    WebObjectsException - Thrown if the parent of the given nodes is not aa branch qualification operator, the two given nodes do not share the same parent, or if either the first node, second node, or the shared parent node are the root node of the expression.
    
    java.lang.IllegalArgumentException - Thrown if one of the keys given is not found in the expression.
    
    See Also:
    
    consolidateTree()
  - delete
```
void delete(WebNode node)
     throws java.lang.IllegalArgumentException
```
    Delete the specified node from the expression. If it is the root node of the expression, this method will do nothing.
    
    Parameters:
    
    node - The node to be deleted.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if the input parameter is null.
  - delete
```
void delete(int nodeKey)
     throws java.lang.IllegalArgumentException
```
    Delete the node with the given key from the expression. If it is the root node of the expression, this method will do nothing.
    
    Parameters:
    
    nodeKey - The key of the node to be deleted.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if the key is not found in the expression.
  - canGroup
```
boolean canGroup(WebNode firstNode,
                 WebNode secondNode)
          throws java.lang.IllegalArgumentException
```
    Check whether it is possible to call group() on the two given nodes.
    
    Parameters:
    
    firstNode - The first node.
    
    secondNode - The second node.
    
    Returns:
    
    True if calling group() on the two given nodes will not cause an error, or false if it is not possible to group the two given nodes.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if either input parameter is null.
  - canGroup
```
boolean canGroup(int firstKey,
                 int secondKey)
          throws java.lang.IllegalArgumentException
```
    Check whether it is possible to call group() on the two nodes with the given keys.
    
    Parameters:
    
    firstKey - The key of the first node.
    
    secondKey - The key of the second node.
    
    Returns:
    
    True if calling group() on the two given nodes will not cause an error, or false if it is not possible to group the two given nodes.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if either key does not exist in the expression.
  - canUngroup
```
boolean canUngroup(WebNode firstNode,
                   WebNode secondNode)
            throws java.lang.IllegalArgumentException
```
    Check whether it is possible to call ungroup() on the two given nodes.
    
    Parameters:
    
    firstNode - The first node.
    
    secondNode - The second node.
    
    Returns:
    
    True if calling ungroup() on the two given nodes will not cause an error, or false if it is not possible to ungroup the two given nodes.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if either input parameter is null.
  - canUngroup
```
boolean canUngroup(int firstKey,
                   int secondKey)
            throws java.lang.IllegalArgumentException
```
    Check whether it is possible to call ungroup() on the two nodes with the given keys.
    
    Parameters:
    
    firstKey - The key of the first node.
    
    secondKey - The key of the second node.
    
    Returns:
    
    True if calling ungroup() on the two given nodes will not cause an error, or false if it is not possible to ungroup the two given nodes.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if either key does not exist in the expression.
  - canSwapWithPrevious
```
boolean canSwapWithPrevious(WebNode node)
                     throws java.lang.IllegalArgumentException
```
    Checks whether it is possible to call swapWithPrevious() on the given node.
    
    Parameters:
    
    node - The node to be swapped.
    
    Returns:
    
    True if swapWithPrevious will not cause an error, false otherwise.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if the node parameter is null.
  - canSwapWithPrevious
```
boolean canSwapWithPrevious(int nodeKey)
                     throws java.lang.IllegalArgumentException
```
    Checks whether it is possible to call swapWithPrevious() on the node with the given key.
    
    Parameters:
    
    nodeKey - The key of the node to be swapped.
    
    Returns:
    
    True if swapWithPrevious will not cause an error, false otherwise.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if the node parameter is null.
  - canSwapWithNext
```
boolean canSwapWithNext(WebNode node)
                 throws java.lang.IllegalArgumentException
```
    Checks whether it is possible to call swapWithNext() on the given node.
    
    Parameters:
    
    node - The node to be swapped.
    
    Returns:
    
    True if swapWithNext will not cause an error, false otherwise.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if the node parameter is null.
  - canSwapWithNext
```
boolean canSwapWithNext(int nodeKey)
                 throws java.lang.IllegalArgumentException
```
    Checks whether it is possible to call swapWithNext() on the node with the given key.
    
    Parameters:
    
    nodeKey - The key of the node to be swapped.
    
    Returns:
    
    True if swapWithNext will not cause an error, false otherwise.
    
    Throws:
    
    java.lang.IllegalArgumentException - Thrown if the node parameter is null.
  - canEditExpression
```
boolean canEditExpression()
```
    Since:
    
    MicroStrategy Web 9.0.0
  - getNewRootNode
```
WebOperatorNode getNewRootNode()
```
    Creates a new root node for the underlying WebExpression. The new root node has function EnumDSSXMLFunction.DssXmlFunctionAnd and expression type EnumDSSXMLExpressionType.DssXmlFilterBranchQual. If the specified WebExpression has any sub expression originally, the sub expression becomes the first child of the new root node after the method call returns.
    
    Returns:
    
    a new root node for the specified expression object.
    
    Since:
    
    MicroStrategy Web 9.0.0
  - hasFilterOn
```
boolean hasFilterOn(WebObjectInfo oi)
```
    Returns whether the expression contains an qualification on specified object
  - compareTo
```
boolean compareTo(WebExpression anotherExp)
```
    Compares two WebExpression. The comparison is based on the structure of each root node in the expressions.
    Note that this method is currently used to compare the expressions which are used in derived elements editor.
    
    Parameters:
    
    anotherExp - the WebExpression to be compared..
    
    Returns:
    
    true if this expression is the same as the anotherExp argument; false otherwise.
    
    See Also:
    
    isEqual(WebNode, WebNode)
  - isEqual
```
boolean isEqual(WebNode n1,
                WebNode n2)
```
    Checks whether two WebNode are equal.
    Note that this method is currently used to compare the expressions which are used in derived elements editor.
    
    Parameters:
    
    n1 - the first WebNode to check equality
    
    n2 - the second WebNode to check equality
    
    Returns:
    
    true if the two WebNode are the same; false otherwise.
  - validateOperands
```
boolean validateOperands(WebNode node,
                         RWDataSet ds)
```
    Returns whether the given node and its children are valid. The primary use of this is to ensure that the given node is valid within the given RW context.
    
    Parameters:
    
    node - The WebNode object which will be validated. If null is passed, then the validation will start at the root. Note that all children will be validated as well.
    
    ds - The dataset which is used to validate if it contains the operand objects
    
    Returns:
    
    True if the expression is valid, false if it is not.
    
    Since:
    
    MicroStrategy Web 9.4.0

Interface WebExpressionHelper

Method Summary

Method Detail

getAutoConsolidation

setAutoConsolidation

consolidateTree

removeEmptyFilters

group

group

ungroup

ungroup

swap

swap

swapWithPrevious

swapWithPrevious

swapWithNext

swapWithNext

toggleFunction

toggleFunction

delete

delete

canGroup

canGroup

canUngroup

canUngroup

canSwapWithPrevious

canSwapWithPrevious

canSwapWithNext

canSwapWithNext

canEditExpression

getNewRootNode

hasFilterOn

compareTo

isEqual

validateOperands