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Difference between revisions of "BaSyx / Documentation / VAB / TCP Mapping"
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== DELETE == | == DELETE == | ||
| − | + | There are two variants of delete: Deleting a value from a path and deleting a value from a Collection in a given path. In the latter case, the object to be deleted will be passed as JSON string. | |
=== Request === | === Request === | ||
{| class="wikitable" | {| class="wikitable" | ||
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| Path to element as string | | Path to element as string | ||
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| + | |- | ||
| + | | <variable> | ||
| + | | '''Optional''' Object to be deleted from collection as JSON string | ||
|} | |} | ||
Revision as of 08:00, 26 May 2020
| See also | HTTP/REST Mapping | JSON Serialization |
|---|
BaSyx defines a mapping of the VAB primitives to a TCP protocol, called BaSyx Native.
General Frame Format
Each BaSyx Native frame is divided into two fields. These fields define message size and message payload. Due to this, the receiver can create a appropriate sized buffer.
If a message is received with size > Message Length, an error is assumed and the message it is discarded.
| Length | Field |
|---|---|
| 4 Byte, LSB first | Payload Length |
| Variable, as defined in Payload Length | Message payload |
String Encoding
Strings are encoded in the following scheme:
| Length | Field |
|---|---|
| 4 Byte, LSB first | String Length |
| Variable, as defined in String Length | String content, without null termination |
Object Encoding
Collections/Maps are serialized to a string as defined in the JSON serialization and send as a string as defined above.
Primitive Mapping
For a detailed description of the primitives, see the VAB documentation.
RETRIEVE
Request
| Length | Field | Value |
|---|---|---|
| 1 Byte | Command | 0x01 |
| <variable> | Path to element as string |
Response
| Length | Field |
|---|---|
| 1 Byte | Result |
| <variable> | Value serialized as JSON |
Currently, the result will always be 0x00 with exceptions encoded in the returned string.
Exceptions
If the property specified in the path or one of its parent elements does not exist, a ResourceNotFound Exception will be returned.
If the parent element of the specified property is a list, a ResourceNotFound Exception will be returned.
If another error occurs and the property can't be retrieved, a MalformedRequest Exception will be returned.
UPDATE
Request
| Length | Field | Value |
|---|---|---|
| 1 Byte | Command | 0x02 |
| <variable> | Path to element as string | |
| <variable> | Value serialized as JSON |
Response
| Length | Field |
|---|---|
| 1 Byte | Result |
| <variable> | Value serialized as JSON |
Currently, the result will always be 0x00 with exceptions encoded in the returned string.
Exceptions
If the parent element of the property specified in the path is a list, a ResourceNotFound Exception is returned.
If another error occurs while trying to set the property, a MalformedRequest Exception is returned.
CREATE
Request
| Length | Field | Value |
|---|---|---|
| 1 Byte | Command | 0x03 |
| <variable> | Path to element as string | |
| <variable> | Value serialized as JSON |
Response
| Length | Field |
|---|---|
| 1 Byte | Result |
| <variable> | Value serialized as JSON |
Currently, the result will always be 0x00 with exceptions encoded in the returned string.
Exceptions
If one of the parent elements specified in the path does not exist, a ResourceNotFound exception will be returned.
If the property already exists, a ResourceAlreadyExists exception will be returned.
If the new property could not be created, a MalformedRequest exception will be returned.
DELETE
There are two variants of delete: Deleting a value from a path and deleting a value from a Collection in a given path. In the latter case, the object to be deleted will be passed as JSON string.
Request
| Length | Field | Value |
|---|---|---|
| 1 Byte | Command | 0x04 |
| <variable> | Path to element as string | |
| <variable> | Optional Object to be deleted from collection as JSON string |
Response
| Length | Field |
|---|---|
| 1 Byte | Result |
Currently, the result will always be 0x00 with exceptions encoded in the returned string.
Exceptions
If the property specified in the path or one of its parent elements does not exist, a PropertyNotFound exception is returned.
If the property could not be deleted, a MalformedRequest exception is returned.
INVOKE
Request
| Length | Field | Value |
|---|---|---|
| 1 Byte | Command | 0x05 |
| <variable> | Path to operations as string | |
| <variable> | Return value serialized as JSON |
Response
| Length | Field |
|---|---|
| 1 Byte | Result |
| <variable> | Value serialized as JSON |
Currently, the result will always be 0x00 with exceptions encoded in the returned string.
Exceptions
If the property specified in the path or one of its parent elements does not exist, a PropertyNotFound exception is returned.
If invoke is called on an object that is not a function, a ProviderException will be returned.