Process data by ‘jsondata.JSONPatch’

The module jsondata.JSONPatch provides patch operations in accordance to RFC6901.

Basic types of provided basic operations are:

• Pointer Arithmetics: Manipulates and calculates the pointer itself. Thus the comparison is related to the resulting contained set. Where the shorter matching pointer path contains more elements, than the longer, which itself is contained in the matching shorter path.
• Pointed Value Evaluation: Fetches values from JSON documents. Thus the comparison is related to the resulting values pointed to by the pointer path.
• Calculations with Pointed Values: Applies common arithmetics on to evaluated values and numeric parts of pointers.

Syntax Elements

The current release provides the following operators for the class ‘JSONPointer’.

Class Components:

• JSONPatch: Job manager for the complete set tasks represented by patch items.
• JSONPatchItem: A task in accordance to RFC6901 stored as patch item. The creation requires the parameters to be prepared for the record format.
• JSONPatchItemRaw: Splits a raw JSON patch string into the record format for JSONPatchItem.

Job Manager

Job list comparison:

ops := '==' | '!='

Add and remove task entries:

ops := '+' | '+=' | '-' | '-='

Task execution operators:

ops := '()'

Miscellaneous operators:

ops := __len__ | '[]' | '()'

Keyword operators:

ops := apply | get | patch_export | patch_import

Task Items

Task comparison:

ops := '==' | '!='

Task execution operators:

ops := '()'

Keyword operators:

ops := apply

Examples

Examples for the provided basic calculations are:

Create List

• Create a Job List:

  jsonpatchlist = JSONPatch()
  

Add Item

• Add a Task Item:

  jsonpatchlist = JSONPatch()
  for i in range(0,10):
      jsonpatchlist += JSONPatchItem("add", "/a"+unicode(i), "v"+unicode(i))
  

Remove Item

• Remove a Task Item:

  jsonpatchlist -= 8
  
  x = jsonpatchlist[1]
  jsonpatchlist -= x
  

Apply List

• Apply the Job List:

  n,err = jsonpatchlist(configdata)
  assert n == 5
  assert err == []
  

Apply Item

• Apply a Task Item:

  n,err = jsonpatchlist(configdata,0)
  ref = { "a0": "v0", "foo": "bar" }
  assert n == 1
  assert err == []
  assert ref == configdata
  

Export List

• Export Job List:

  filepath = os.path.dirname(__file__)+os.sep+"export.jsonp"
  ret = jsonpatchlist.patch_export(filepath)
  assert ret
  

Import List

• Import Job List:

  implist = JSONPatch()
  imppatch = implist.patch_import(filepath)
  assert imppatch
  
  assert implist == jsonpatchlist.patch
  assert implist == jsonpatchlist