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Update spec with RFC6902

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PhatPhuckDave
2025-09-26 10:19:50 +02:00
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Spec.md
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@@ -88,3 +88,148 @@ At the end of the day merging the event log should make no changes to the data
Actually for pocketbase we might want to generalize this
Maybe create a "Collection" field as well and allow the events to manipulate any table...
That way our Data isn't tied to a table...
## RFC6902
Wait actually we can use RFC6902
"JSON patch standard"
It defines a way to apply patches to JSON documents...
Exactly what we need
https://datatracker.ietf.org/doc/html/rfc6902
Some highlights:
Operation objects MUST have exactly one "op" member, whose value
indicates the operation to perform. Its value MUST be one of "add",
"remove", "replace", "move", "copy", or "test"; other values are
errors. The semantics of each object is defined below.
Additionally, operation objects MUST have exactly one "path" member.
That member's value is a string containing a JSON-Pointer value
[RFC6901] that references a location within the target document (the
"target location") where the operation is performed.
The meanings of other operation object members are defined by
operation (see the subsections below). Members that are not
explicitly defined for the operation in question MUST be ignored
(i.e., the operation will complete as if the undefined member did not
appear in the object).
Note that the ordering of members in JSON objects is not significant;
therefore, the following operation objects are equivalent:
{ "op": "add", "path": "/a/b/c", "value": "foo" }
{ "path": "/a/b/c", "op": "add", "value": "foo" }
{ "value": "foo", "path": "/a/b/c", "op": "add" }
Operations are applied to the data structures represented by a JSON
document, i.e., after any unescaping (see [RFC4627], Section 2.5)
takes place.
## add
The "add" operation performs one of the following functions,
depending upon what the target location references:
o If the target location specifies an array index, a new value is
inserted into the array at the specified index.
o If the target location specifies an object member that does not
already exist, a new member is added to the object.
o If the target location specifies an object member that does exist,
that member's value is replaced.
The operation object MUST contain a "value" member whose content
specifies the value to be added.
For example:
{ "op": "add", "path": "/a/b/c", "value": [ "foo", "bar" ] }
When the operation is applied, the target location MUST reference one
of:
o The root of the target document - whereupon the specified value
becomes the entire content of the target document.
o A member to add to an existing object - whereupon the supplied
value is added to that object at the indicated location. If the
member already exists, it is replaced by the specified value.
o An element to add to an existing array - whereupon the supplied
value is added to the array at the indicated location. Any
elements at or above the specified index are shifted one position
to the right. The specified index MUST NOT be greater than the
number of elements in the array. If the "-" character is used to
index the end of the array (see [RFC6901]), this has the effect of
appending the value to the array.
Because this operation is designed to add to existing objects and
arrays, its target location will often not exist. Although the
pointer's error handling algorithm will thus be invoked, this
specification defines the error handling behavior for "add" pointers
to ignore that error and add the value as specified.
However, the object itself or an array containing it does need to
exist, and it remains an error for that not to be the case. For
example, an "add" with a target location of "/a/b" starting with this
document:
{ "a": { "foo": 1 } }
is not an error, because "a" exists, and "b" will be added to its
value. It is an error in this document:
{ "q": { "bar": 2 } }
because "a" does not exist.
## remove
The "remove" operation removes the value at the target location.
The target location MUST exist for the operation to be successful.
For example:
{ "op": "remove", "path": "/a/b/c" }
If removing an element from an array, any elements above the
specified index are shifted one position to the left.
## replace
The "replace" operation replaces the value at the target location
with a new value. The operation object MUST contain a "value" member
whose content specifies the replacement value.
The target location MUST exist for the operation to be successful.
For example:
{ "op": "replace", "path": "/a/b/c", "value": 42 }
This operation is functionally identical to a "remove" operation for
a value, followed immediately by an "add" operation at the same
location with the replacement value.
## move
The "move" operation removes the value at a specified location and
adds it to the target location.
The operation object MUST contain a "from" member, which is a string
containing a JSON Pointer value that references the location in the
target document to move the value from.
The "from" location MUST exist for the operation to be successful.
For example:
{ "op": "move", "from": "/a/b/c", "path": "/a/b/d" }
This operation is functionally identical to a "remove" operation on
the "from" location, followed immediately by an "add" operation at
the target location with the value that was just removed.
The "from" location MUST NOT be a proper prefix of the "path"
location; i.e., a location cannot be moved into one of its children.
## copy
The "copy" operation copies the value at a specified location to the
target location.
The operation object MUST contain a "from" member, which is a string
containing a JSON Pointer value that references the location in the
target document to copy the value from.
The "from" location MUST exist for the operation to be successful.
For example:
{ "op": "copy", "from": "/a/b/c", "path": "/a/b/e" }
This operation is functionally identical to an "add" operation at the
target location using the value specified in the "from" member.
## test
I think we don't care about this one
For this then use the PATCH http method
And simply submit patches one by one
"Patch" here is synonymous with our "event"
Well nearly, a patch is part of an event