Nepomuk.Query.QueryParser

KDE 4.5 PyKDE API Reference

- KDE's Python API

# QueryParser Class Reference

`from PyKDE4.nepomuk import *`

Namespace: Nepomuk.Query

## Detailed Description

\class QueryParser queryparser.h Nepomuk/Query/QueryParser

Parser for desktop user queries.

The QueryParser can be used to parse queries and convert them into Query instances.

The syntax is fairly simple: plain strings match to LiteralTerm terms, URIs need to be N3-encoded, when using white space parenthesis need to be put around properties and values, terms can be excluded via '-'.

Examples

%Query everything that contains the term "nepomuk":

     nepomuk

%Query everything that contains both the terms "Hello" and "World":

     Hello World

%Query everything that contains the term "Hello World":

     "Hello World"

%Query everything that has a tag whose label matches "nepomuk" (actually this is where Query.resolveProperties would match "hastag" to nao:hasTag):

     hastag:nepomuk

%Query everything that has a tag labeled "nepomuk" or a tag labeled "scribo:

     hastag:nepomuk OR hastag:scribo

%Query everything that has a tag labeled "nepomuk" but not a tag labeled "scribo":

     +hastag:nepomuk AND -hastag:scribo

The parser can handle one special case of nesting (TODO: implement a "real" parser) which matches all resources that are related to a resource which in turn has a certain property:

     related:(hastag:nepomuk)

Author:
  Sebastian Trueg <trueg@kde.org>

Since:
  4.4

## Enumerations
ParserFlag | { NoParserFlags, QueryTermGlobbing }
## Methods
| __init__ (self)
[Nepomuk.Types.Property] | matchProperty (self, QString fieldName)
Nepomuk.Query.Query | parse (self, QString query)
Nepomuk.Query.Query | parse (self, QString query, Nepomuk.Query.QueryParser.ParserFlags flags)
## Static Methods
Nepomuk.Query.Query | parseQuery (QString query)

## Method Documentation

__init__ | ( |  | self ) |

Create a new query parser.

[Nepomuk.Types.Property] matchProperty | ( | self, |
|  | QString | fieldName
| ) |  |  |

Try to match a field name as used in a query string to actual properties.

The matching is cached inside the Query instance for fast subsequent lookups.

Example:

     hastag:nepomuk

Returns:
  A list of properties that match fieldName or an empty list in case nothing was matched.

This method is used by parse() to match properties used in user queries.

Nepomuk.Query.Query parse | ( | self, |
|  | QString | query
| ) |  |  |

Parse a user query.

Parameters:

  | query | The query string to parse

Parameters:

  | flags | a set of flags influencing the parsing process.

Returns:
  The parsed query or an invalid Query object in case the parsing failed.

Since:
  4.5

Nepomuk.Query.Query parse | ( | self, |
|  | QString | query,
|  | Nepomuk.Query.QueryParser.ParserFlags | flags
| ) |  |  |

Parse a user query.

Parameters:

  | query | The query string to parse

Parameters:

  | flags | a set of flags influencing the parsing process.

Returns:
  The parsed query or an invalid Query object in case the parsing failed.

Since:
  4.5

## Static Method Documentation

Nepomuk.Query.Query parseQuery | ( | QString | query
| ) |  |  |

Convenience method to quickly parse a query without creating an object.

Returns:
  The parsed query or an invalid Query object in case the parsing failed.

## Enumeration Documentation

ParserFlag

Flags to change the behaviour of the parser.

Since:
  4.5

Enumerator:

  NoParserFlags = 0x0 |
  QueryTermGlobbing = 0x1 |