GSoC 2014 Metadata for GRASS GIS maps and datasets

Title:	Metadata for GRASS GIS maps and datasets
Student Name:	Matej Krejci, ​Czech Technical University in Prague

Organization:

​OSGeo - Open Source Geospatial Foundation

Mentor Name:

​Martin Landa, ​Margherita Di Leo

GSoC proposal:

​view proposal

Link to code:

​https://trac.osgeo.org/grass/browser/sandbox/krejcmat

Motivation

Current GRASS GIS offers just a poor and out-of-date administration of metadata. The goal of this project is to implement administration of metadata according to the standards of ISO 19115, ISO 19139 and to create a graphical user interface which would allow the user to operate with metadata, such as creating, updating, browsing, searching etc.

Timeline

timeline from proposal		newly proposed timeline	status
MAY 1- 7	"Early starts" Study ISO, INSPIRE and FGDC standards		+
MAY 7 - 14	Getting familiar with GRASS GIS modules code.		+
MAY 14 - 19	Design of metadata GRASS library	design GRASS library (in Python) to read / write metadata based on ISO as flat XML files	+
MAY 19	Starting GoSC x		+
MAY 19- 25	Support of different metadata profiles	design GRASS library (in Python) to read / write metadata based on ISO as flat XML files including profies (XSD validation, Inspire as the show-case)	+
MAY 26 - JUN 16	"Break"(Prepare for bachelor final exam)	add support for conversion GRASS (current) metadata files <-> XML ISO metadata	+
JUN 16 - 24	Implement basic library model for command line	design cmd modules for reading and writing ISO-based metadata -> r.info.iso + v.info.iso (including support for conversion GRASS (current) metadata files <-> XML ISO metadata)	+
JUN 24 - 30	Modules functionality (searching, publishing metadata)	design GUI for reading and writing ISO-based metadata
JULY 1 - 7	Design GUI	design GUI for reading and writing ISO-based metadata -> g.gui.metadata
JULY 7 - 14	Connect GUI library, basic functions	advanced metadata publishing/searching based on owslib + pycsw
JULY 14 - 21	Implementation of search function to GUI	advanced metadata publishing/searching based on owslib + pycsw
JULY 21 - 30	Improve metadata validation using designed GUI	advanced metadata publishing/searching based on owslib + pycsw -> testing prototype
AUGUST 1 - 9	Polishing code	polishing code
AUGUST 9 - 18	Testing and documentation	testing and documentation
AUGUST 18	The end of GSoC	the end of GSoC

Development

Dependencies

Current development of metadata management has dependence on external libraries:

• OWSLib (no additional dependence),
• Jinja templates (suitable to remove dependence)

Architecture

The new designed metadata management in GRASS is based on external python modules without processing of the GRASS core.

• First step which is partly done is to create basic modules for exporting ISO based metadata for raster and vector maps. The modules are intended to implement class that is providing parsing metadata from r.info and v.info. These metadata are assigned to ISO attributes with using OWSLib. The OWSLib is offering creation instances of ISO elements. The instances are suitable to filled predefined of Jinja xml ISO profiles. From this part of project r.info.iso and v.info.iso are created.

r.info.iso and v.info.iso

• These modules are based on the mentioned implementation.
• Offers converting metadata from *.info to xml file based on ISO standard.
• Currently available metadata profile for GRASS:
  • INSPIRE profile,
  • GRASS BASIC profile - this profile is mainly including available metadata from GRASS.

g.gui.metadata

Current task is to design and the implementation of the GUI interface. Below is the first design provided. Main aggravating factor is, that some attributes in ISO can be defined multiple times. For the solution, there is necessary to create interface for getting information from some source. Currently the easiest way is to get information forom predefined XML Jinja template. Interface ensures independence between editor and source of information. This is useful for future development steps. The editor will support:

version	function
1.0	to implement main window and layout
	function for browsing maps with using treeCtrl
	to create xml ISO file (with using v/r.info.iso)
	interface to get information about ISO attributes
1.1	editing of created xml files with using Jinja templates
1.2	to add multiple values for specific attributes
1.3	validator of inspire xml
	options for update metadata with using r/v.support by changed values in editor.
1.4	multiple metadata editing ( choosing maps invokes process that changes selected attributes of all chosen maps.

scheme of designed implementation

draft of GUI for choosing ISO profile or options edit xml only

draft of GUI editor

Weekly reports

Week 1 (May 23)

studied metadata and tried to find suitable python lib during last three weeks:

• studied ISO 19115 and EN ISO 19119
  • INSPIRE
  • be advised to leave out implementation of FGDC - just ISO, INSPIRE
• get familiar with OWSLib and pycsw
  • set pycsw metadata server catalog
  • handled metadata by OWSLib
• spent time with design lib based on automated generation of XML from XSD - failed
• tested suitability of generateDS to generate python object from XML scheme (XSD)
• designed library for parse GRASS GIS metadata to XML based on md. ISO
  • parsed metadata from:
    • r.info
    • v.info
• designed essential metadata profile for raster and vector maps (based on ISO standard)
  • prepared lib for new update of OWSLib that will be ready during next week. (in contact with author)
• created new timeline - main changes:
  • will create basic metadata management based on creating, editing, validating ISO. (obligatory)
  • will create advanced management based on client-server with using pycsw. (optional)

​report email

Week 2 (May 30)

created cmd modules for writing ISO-based metadata -> r.info.iso + v.info.iso support:

• basic grass ISO profile
• inspire profile (for subsequent editing in future wxGUI editor)

​report email

Week 3 (June 06)

• Consulted design of metadata editor with mentors.
• Consulted current implementation of v.info.iso and r.info.iso
• Search for alternatives to Jinja templates (current implementation)
• Learned basics of wxPython

​report email

Week 4 (June 13)

​report email