====== Orbit Composite Resource ======

The Orbit Composite Resource (*.ocr) is Orbit's native grouping resource file to combine multiple [[2210:technology:supported_formats:index|any supported vector, image and raster resource]] via simple file referencing. \\
An OCR store no data, but only file pointers. 

=== Structure ===

An OCR is a multi-model dataset. Every reference resource appears as individual model. \\
More information about dataset structure concepts, see [[2210:technology:supported_formats:vector:ovf|]].

An OCR can group a fix list of reference resources (Defined OCR) or combine all files within one or more reference folders (Undefined OCR). 

=== Reasons to Use ===

The OCR is an easy way to combine multiple resources into one read only, multi-model dataset to be used in Orbit. \\
For example a single dataset grouping frequently updated shapefiles, thematic resources or all image tiles of an orthophoto. 

There is technically no limitation on the number of resources that can be combined into one OCR. \\
However, be aware that every included resource is stored in memory when opening the OCR. When combining lots of static resources, we recommend to merge these resources into Orbit's native optimized formats, see [[2210:technology:supported_formats:vector:ovt|]] and [[2210:technology:supported_formats:image:omi|]].

Some remarks regarding combined resources of an OCR : 
  * All resources must have the same [[2210:technology:core:crs|Dataset Coordinate Reference System]]. 
  * All resources must be available available in the root or sub-directory of the OCR file location.
  * Web based resources cannot be added.

=== Create and Update ===

  * An OCR can be created using a standard text editor. Use the examples below as reference, save as ascii text and change file extension into.
  * Any Dataset List can be exported as Defined OCR from the Workspace Menu, see [[2210:desktop:workspace:main_toolbar|]].

The Dataset Model usernames cannot be renamed via the Dataset Structure panel. If needed, rename Model usernames by editing directly the accompanied ord file, see [[2210:technology:supported_formats:other:ord|]].

=== Examples ===

View and edit using a standard text editor (e.g. Notepad).

** Defined OCR **

<code bash>
<Content>
    <ResourceList>
        <Resource>
            <Location>map1.shp</Location>
            <ResourceDriver>com.eurotronics.orbitx.driver.shape.ShapeDriver</ResourceDriver>
        </Resource>
        <Resource>
            <Location>map2.ovf</Location>
            <ResourceDriver>com.eurotronics.orbitx.driver.shape.ShapeDriver</ResourceDriver>
        </Resource>
        <Resource>
            <Location>ortho.omi</Location>
            <ResourceDriver>com.eurotronics.orbitx.driver.geoimage.GeoImageDriver</ResourceDriver>
        </Resource>
    </ResourceList>
</Content>
</code>

** Undefined OCR **

Following OCR groups all ovf resources inside the ocr's subdirectory "ovf_resources".

<code bash>
<Content>
    <ResourceList>
        <ResourceFilter>
            <FileNameFilter>/ovf_resources/*.ovf</FileNameFilter>
            <SubFolders>false</SubFolders>
        </ResourceFilter>
    </ResourceList>
</Content>
</code>

=== Legend and Georeference ===

The resource can be accompanied by an [[2210:technology:supported_formats:other:olg|]] and [[2210:technology:supported_formats:other:ord|]].