XML metadata terminology

This section defines the terminology used in this guide to describe the XML metadata structures and values used by VWorks software.

XML blocks and XML elements

The following terms describe the structure of the XML metadata that is passed in the input and output parameters of VWorks Plugin methods.

Note: Normally, non-XML data is not documented in the methods sections.

XML structures

VWorks software uses the following XML structures, which are passed as strings to VWorks Plugin methods:

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XML block

An XML block is a portion of an XML byte string that contains a parent element and all its children. All XML blocks include the XML declaration and most contain the Velocity11 root element. In addition, some XML blocks contain the MetaData element.

The following code is an example of a CompilerErrors XML block.

 

<?xml version='1.0' encoding='ASCII' ?> <Velocity11 file='MetaData' →md5sum='849392019ca47102839e845113d11840' version='1.0'> <MetaData> <CompilerErrors> <CompilerError Value='Warning: xyz' ErrorType='1'> <CompilerError Value='Warning: xyzabc' ErrorType='1'> </CompilerErrors> </MetaData> </Velocity11>

•	XML element

An XML element is a portion of an XML byte string that contains an element that has no children. All XML elements include the XML declaration and most contain the Velocity11 root element.

The following code is an example of an analogInput XML element.

 

<?xml version='1.0' encoding='ASCII' ?> <Velocity11 file='Velocity11' →md5sum='cc239a8f99203e73b3de0ed8a058f77e' version='1.1' > <analogInput name='Humidity' value='70' /> </Velocity11>

Escaped XML blocks

Whenever an XML block is used as the value of an XML attribute, the following five special characters that are used in XML markup should be escaped: <, >, &, ', and ".

Using escaped XML blocks in Parameter elements instead of specifying additional attributes is recommended. This simplifies the user interface and allows for future expansion.

For sample code that shows an escaped XML block, see “Example of an AllDeviceInfo query response” .

Empty XML blocks and elements

This section contains examples of empty XML structures.

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XML block

If an XML block is empty, only its empty parent element is specified.

The following code is an example of an empty DeviceLocationTeachpoints XML block.

 

<?xml version='1.0' encoding='ASCII' ?> <Velocity11 file='MetaData' md5sum='a16eb3001ae9fcd2ff3fd34654eba2d5' version='1.0' > <DeviceLocationTeachpoints /> </Velocity11>'

•	Query and Update XML blocks

An empty Query or Update XML block includes the parent element’s Category attribute.

The following code is an example of an empty Query XML block.

 

<?xml version='1.0' encoding='ASCII' ?> <Velocity11 file='Query' md5sum='caa52e1e5fae3c9dbea6cdc245eb3485' version='1.0' > <Query Category='GetDeviceName' /> </Velocity11>

The following code is an example of an empty Update XML block.

 

<?xml version='1.0' encoding='ASCII' ?> <Velocity11 file='Update' md5sum='0b8eb2ad5df221c13e336af98ffec528' version='1.0' > <Update Category='InventoryPlateBarcodes' /> </Velocity11>

•	XML element

If an XML element is empty, none of its element’s attributes is specified.

The following code is an example of an empty RobotPickComplete XML element.

 

<?xml version='1.0' encoding='ASCII' ?> <Velocity11 file='MetaData' md5sum='3c2d69b02b8e7505682cfb59c06a0105' version='1.0' > <RobotPickComplete /> </Velocity11>

XML attribute values

In this guide, some XML attribute values are identified as not specified or as having no value.

Not specified

If an attribute is not specified, it is not present in the code.

In the following code, the Labware element is not specified for the third and fourth Layout elements.

 

<Layout Labware='Labware Type 1' Name='Location 1' /> <Layout Labware='Labware Type 2' Name='Location 2' /> <Layout Name='Location 3' /> <Layout Name='Location 4' />

No value

If an attribute has no value, its value is empty.

In the following code, the OptionalDevice attribute has no value.

 

<VolumeUpdates Location='Stage 1' OptionalDevice='' ResetAbsolute='0' >