The FieldExpression Class

Class FieldExpression allows you to compute customized content snippets for each result returned by a search.

FieldExpression is defined in the module google.appengine.api.search .

Constructor

The constructor for class FieldExpression is defined as follows:

class FieldExpression ( name , expression )

Construct an instance of class FieldExpression .

For example,

 FieldExpression 
 ( 
 name 
 = 
 'content_snippet' 
 , 
 expression 
 = 
 'snippet("very important", content)' 
 ) 

constructs a field expression that returns a computed field named content-snippet with each search result, containing HTML snippets of the content field that match the query "very important" .

Arguments

name

Name of computed field.

expression

Expression to evaluate and return.

Result value

A new instance of class FieldExpression .

Exceptions

TypeError

A parameter has an invalid type, or an unknown attribute was passed.

ValueError

A parameter has an invalid value.

Properties

An instance of class FieldExpression has the following properties:

name

Name of computed field.

expression

String containing expression to evaluate and return.