Serialization utilities — blockr

Object serialization is available via to_json(), while de-serialization is available as from_json(). Blocks are serialized by writing out information on the constructor used to create the object, combining this with block state information, which constitutes values such that when passed to the constructor the original object can be re-created.

Usage

blockr_ser(x, ...)

# S3 method for class 'block'
blockr_ser(x, state = NULL, ...)

# S3 method for class 'blocks'
blockr_ser(x, blocks = NULL, ...)

# S3 method for class 'board_options'
blockr_ser(x, options = NULL, ...)

# S3 method for class 'board'
blockr_ser(x, blocks = NULL, options = NULL, ...)

# S3 method for class 'link'
blockr_ser(x, ...)

# S3 method for class 'links'
blockr_ser(x, ...)

# S3 method for class 'stack'
blockr_ser(x, ...)

# S3 method for class 'stacks'
blockr_ser(x, ...)

blockr_deser(x, ...)

# S3 method for class 'list'
blockr_deser(x, ...)

# S3 method for class 'block'
blockr_deser(x, data, ...)

# S3 method for class 'blocks'
blockr_deser(x, data, ...)

# S3 method for class 'board'
blockr_deser(x, data, ...)

# S3 method for class 'link'
blockr_deser(x, data, ...)

# S3 method for class 'links'
blockr_deser(x, data, ...)

# S3 method for class 'stack'
blockr_deser(x, data, ...)

# S3 method for class 'stacks'
blockr_deser(x, data, ...)

# S3 method for class 'board_options'
blockr_deser(x, data, ...)

to_json(x, ...)

from_json(x)

Arguments

x: Object to (de)serialize
...: Generic consistency
state: Object state (as returned from an expr_server)
blocks: Block states (NULL defaults to values from ctor scope)
options: Board option values (NULL means default values)
data: List valued data (converted from JSON)

Value

Serialization helper function blockr_ser() returns lists, which for most objects contain slots object and payload, where object contains a class vector which is used by blockr_deser() to instantiate an empty object of that class and use S3 dispatch to identify the correct method that, given the content in payload, can re-create the original object. These are wrapped by to_json(), which returns JSON and from_json() which can consume JSON and returns the original object.

Details

Helper functions blockr_ser() and blockr_deser() are implemented as generics and perform most of the heavy lifting for (de-)serialization: representing objects as easy-to-serialize (nested) lists containing mostly strings and no objects which are hard/impossible to truthfully re-create in new sessions (such as environments).

Examples

blk <- new_dataset_block("iris")

blockr_ser(blk)
#> $object
#> [1] "dataset_block" "data_block"    "block"         "vctrs_vctr"   
#> [5] "list"         
#> 
#> $payload
#> $payload$dataset
#> [1] "iris"
#> 
#> $payload$package
#> [1] "datasets"
#> 
#> $payload$name
#> [1] "Dataset block"
#> 
#> 
#> $constructor
#> [1] "new_dataset_block"
#> 
#> $package
#> [1] "blockr.core"
#> 
#> $version
#> [1] "0.1.0"
#> 
to_json(blk)
#> {"object":["dataset_block","data_block","block","vctrs_vctr","list"],"payload":{"dataset":"iris","package":"datasets","name":"Dataset block"},"constructor":"new_dataset_block","package":"blockr.core","version":"0.1.0"} 

all.equal(blk, blockr_deser(blockr_ser(blk)), check.environment = FALSE)
#> [1] TRUE
all.equal(blk, from_json(to_json(blk)), check.environment = FALSE)
#> [1] TRUE