Composite Resource

Introduction

A Composite resource is a resource which can include multiple files without file format limitations. This resource is aimed to support metadata and data functions at both file level and resource level to better support data management in HydroShare. Each file may be annotated with general file type metadata. If a file, or group of files representing one logical object (e.g. multiple files for a shapefile)  is in the format which represents a specific file type supported in HydroShare, the file will be supported with specific file type metadata and additional data functions established for that type (e.g. metadata extraction from TIFF or NetCDF file).

How to Create a Composite Resource

Go to “My Resource” and click on “Create new” button. Then from the dropdown list select “ Composite Resource”. If you want to add files immediately click on Choose Files.  (Files can also be added later).  Click on “Create Resource”.

Add or Edit Metadata

Click on the “pencil” icon in the upper right corner of the resource landing page to switch to editing mode (Fig 2).
You can then add or edit the resource level metadata elements in the same way as would be done for a generic resource type. These metadata elements include: Title, Abstract, Authors, Contributors, Source, Relations, Extended Metadata.  However, the resource Coverage metadata won’t be editable (Fig 3). This metadata will be derived from the file metadata of all the files in the resource.
Initially when files are loaded into a composite resource they are “generic”.  To convert them to one of the supported composite types right click on them and select from a conversion option.  More details on this are given below.

To add or edit file type metadata for a specific file, please click on the file (inside its folder) and then click the “File Metadata” tab (Fig 4). In the tab, it will show the associated metadata elements for this file that can be added or edited. Each file within the resource will have file type metadata elements including: title, keywords, key-value pair extended metadata, temporal coverage and spatial coverage. If the file is a specific supported file type in HydroShare (e.g. geographic raster file type in .tif and .vrt format) , the file type metadata will include more elements to describe the contents in the file.

Use this Resource in HydroShare

Both “Generic Resource” and “Composite Resource” can include multiple files without file format limitations. However, the big difference between them is that the “Composite Resource” will be able to recognize different file types and provide associated file type metadata as well as data functions. This section will introduce the general steps how to convert an uploaded file into a supported file type in HydroShare and how to edit and use them.
This instruction takes the geotiff file as an example. However, there are more file types supported in HydroShare and you may check with them in the table below.
  1. Switch to resource editing mode by clicking the “pencil” icon on the resource landing page.
  2. Upload a geotiff file to a composite resource (Fig 5).

  3. Right click on the geotiff file and select “Set Geo Raster File Type” (Fig 6).


    This will convert the geotiff file as the Geo Raster File Type in HydroShare, which means the system will recognize the geotiff file as a geo raster dataset and will provide corresponding file type metadata and data functions.
  4. After the conversion, a folder will be generated with the original file name (Fig 7).


    Within the folder, a .vrt file is automatically generated. Both .vrt and .tif are grouped together and managed within one “logical folder” to represent one geo raster dataset in HydroShare. All the basic file managing functions such as “rename”, “delete”, “ cut” will be disabled for .vrt or .tif file (Fig 8). You can only edit them on the logical folder level. (e.g. folder named “logan”).

  5. To add/edit the file type metadata under the resource editing mode, click any one of the files within the folder and then click on “File Metadata” tab. The tab will show the corresponding file type metadata (See Fig 4).

Currently, HydroShare supports three file types for composite resource type. In the future, we are going to support more file types such as time series, geographic feature, etc. Please check with the detailed information of these file types and try the functions with your files.

HydroShare File Type List

HydroShare Resource Type

File Format for File Type Recognition

File Type Metadata

Basic File Type Functions

Has Logical Folder (Yes/No)? and File Format in the Folder

Generic Resource

  • Any file format
  • General file type metadata*
  • None
  • No

Geographic Raster

  • .tif
  • .zip (including one .vrt and one/multiple .tif)
  • General file type metadata*
  • Band information
  • Cell information
  • Original Spatial Reference
  • Metadata extraction from file
  • Yes
  • One .vrt and one/multiple .tif

Multidimensional space-time data

  • .nc
  • General file type metadata*
  • Original Spatial Reference
  • Variable
  • Metadata extraction from file
  • Yes
  • One .nc and one .txt

* General file type metadata include: title, keywords, extended metadata, temporal coverage, spatial coverage

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Suggestions to learn more and examples

Credits, Authors, Contributors and Contacts

David Tarboton, Pabitra Dash, Tian Gan

Utah State University, Logan, UT 84322