- Make liveliness errors give more info to trace their cause #1142 through #1147 by @xaviergonz
- Fixed a regression regarding json paths not being correctly rooted to the base #1128 through #1146 by @xaviergonz
- Fixed mobx 5.9.0 compatibility #1143 through #1144 by @xaviergonz
- Made liveliness checking in warn mode log an error so the stack trace can be seen #1142 through #1145 by @xaviergonz
- Fixed JSON path escaping, where '/' and '~' were incorrectly being encoded/decoded as '~0' and '~1' rather than '~1' and '~0'. Also fixed empty keys not being handled correctly by JSON patches #1128. Fixed through #1129 by @xaviergonz
- Fix for safeReference doesn't work when multiple nodes reference a single reference that gets deleted #1115 through #1121 by @xaviergonz
- Little fix for
castFlowReturn
not typecasting the promise to its actual result. - Made
isAlive(node)
reactive, so it can be reacted upon through #1100 by @xaviergonz - Fix for unaccessed nodes not unregistering their identifiers #1112 through #1113 by @xaviergonz
- Added
clear()
toUndoManager
middleware through #1118 by @chemitaxis
- TypeScript 3.0 or later is now required when using TypeScript. This brings some improvements:
flow
arguments and return types are now correctly inferred automatically. One exception is when the last return of aflow
is aPromise
. In these casescastFlowReturn(somePromise)
needs to be used so the return type can be inferred properly.create
method is now smart enough to warn when no snapshot argument is provided on types that have some mandatory properties.
- Added
setLivelinessChecking
andgetLivelinessChecking
, the oldsetLivelynessChecking
will eventually be deprecated. - Added
onInvalidated
option for references andtypes.safeReference
(see readme) through #1091 by @xaviergonz - Added
tryReference
andisValidReference
to use references that might be no longer pointing to any nodes in a safe way through #1087 by @xaviergonz - Readded
IComplexType
for backwards compatibility.
- Fixed non-initialized nodes not being destroyed #1080 through #1082 by @k-g-a
- Fixed a memory leak in createActionTrackingMiddleware when using flow #1083 through #1084 by @robinfehr
- Added castToSnapshot/castToReferenceSnapshot methods for TypeScript and fixed some TypeScript typings not being properly detected when using SnapshotIn types through #1074 by @xaviergonz
- Fixed redux middleware throwing an error when a flow is called before it is connected #1065 through #1079 by @mkramb and @xaviergonz
- Made
addDisposer
return the passed disposer through #1059 by @xaviergonz
- Fixed references to nodes being broken after the node was replaced #1052, plus speed up of reference resolving when using IDs through #1053 by @xaviergonz
- Middleware events now also contain
allParentIds
(chain of causing ids, from root until (excluding) current) - Improved redux dev tools integration, now supporting flows and showing action chains through #1035 based on a fix by @bourquep
- Made type Typescript compilation when 'declarations' is set to true + type completion faster thanks to some type optimizations through #1043 by @xaviergonz
- Fix for array reconciliation of union types with ids #1045 through #1047 by @xaviergonz
- Fixed bug where the eager option for the union type defaulted to true when no options argument was passed but false when it was passed. Now they both default to true when not specified. Fixed through #1046 by @xaviergonz
- Fix for afterCreate/afterAttach sometimes throwing an exception when a node was created as part of a view/computed property #967 through #1026 by @xaviergonz. Note that this fix will only work if your installed peer mobx version is >= 4.5.0 or >= 5.5.0
- Fix for cast method being broken in Typescript 3.1.1 through #1028 by @xaviergonz
- Added getPropertyMembers(typeOrNode) through #1016 by @xaviergonz
- Fix for preProcessSnapshot not copied on compose #613 through #1013 by @theRealScoobaSteve
- Fix for actions sometimes failing to resolve this to self through #1014 by @xaviergonz
- Fix for preProcessSnapshot not copied on compose #613 through #1013 by @theRealScoobaSteve
- Improvements to the bookshop example through #1009 by @programmer4web
- Fix for a regression with optional identifiers #1019 through #1020 by @xaviergonz
- Fix for references sometimes not intializing its parents #993 through #997 by @xaviergonz
- Fix for TS3 issues with reference type #994 through #995 by @xaviergonz
- types.optional will now throw if an instance is directly passed as default value #1002 through #1003 by @xaviergonz
- Doc fixes and improvements by @AjaxSolutions and @agilgur5
- Further improvements for Typescript support for enumeration by @xaviergonz
- Smaller generated .d.ts files through #990 by @xaviergonz
- Fix for exception when destroying children of types.maybe through #985 by @dsabanin
- Fixed incorrect typing generation for mst-middlewares #979
- Fixes for the reconciliation algorithm of arrays #928 through #960 by @liuqiang1357
- Better Typescript support for enumeration, compose, union, literal and references by @xaviergonz
- Updated dependencies to latest versions by @xaviergonz
- [Internal] Cleanup 'createNode' and related codepaths through #962 by @k-g-a
- Made the internal CreationType/SnapshotType/Type official via the new
SnapshotIn
,SnapshotOut
,Instance
andSnapshotOrInstance<typeof X>
by @xaviergonz - A new
cast
method that makes automatic casts from instances/input snapshots for assignments by @xaviergonz
- Fixed typings of
getParent
andgetRoot
. Fixes #951 through #953 by @xaviergonz
- Fixed issue where snapshot post-processors where not always applied. Fixes #926, #961, through #959 by @k-g-a
- Introduced
types.integer
! By @jayarjo through #935 - Improved typescript typings, several fixes to the type system. Awesome contribution by @xaviergonz through #937 and #945. Fixes #922, #930, #932, #923
- Improved handling of
types.late
Welcome to MobX-state-tree! This version introduces some breaking changes, but nonetheless is an recommended upgrade as all changes should be pretty straight forward and there is no reason anymore to maintain the 2.x range (3.0 is still compatible with MobX 4)
MST 3 is twice as fast in initializing trees with half the memory consumption compared to version 2:
Running yarn speedtest
on Node 9.3:
MST 2 | MST 3 | |
---|---|---|
Time | 24sec | 12 sec |
Mem | 315MB | 168MB |
Size (min+gzip) | 14.1KB | 15.0KB |
Beyond that, MST 3 uses TypeScript 2.8, which results in more accurate TypeScript support.
The type system has been simplified and improved in several areas. Several open issues around maps and (numeric) keys have been resolved. The frozen
type can now be fully typed. See below for the full details.
Also, the 'object has died' exception can be suppressed now. One should still address it, but at least it won't be a show-stopper from now on.
- [BREAKING]
types.identifier
can no longer be parameterized with eithertypes.string
ortypes.number
. So instead oftypes.identifier()
usetypes.identifier
. Identifiers are now always normalized to strings. This reflects what was already happening internally and solves a lot of edge cases. To use numbers as identifiers,types.identifierNumber
(instead oftypes.identifier(types.number)
) can be used, which serializes it's snapshot to a number, but will internally work like a string based identifier - [BREAKING]
types.maybe
now serializes to / fromundefined
by default, as it is more and more the common best practice to don't usenull
at all and MST follows this practice. Usetypes.maybeNull
for the old behavior (see #830) - [BREAKING]
types.frozen
is now a function, and can now be invoked in a few different ways:types.frozen()
- behaves the same astypes.frozen
in MST 2.types.frozen(SubType)
- provide a valid MST type and frozen will check if the provided data conforms the snapshot for that type. Note that the type will not actually be instantiated, so it can only be used to check the shape of the data. Adding views or actions toSubType
would be pointless.types.frozen(someDefaultValue)
- provide a primitive value, object or array, and MST will infer the type from that object, and also make it the default value for the fieldtypes.frozen<TypeScriptType>()
- provide a typescript type, to help in strongly typing the field (design time only)
- It is no longer necessary to wrap
types.map
ortypes.array
intypes.optional
when used in amodel
type,map
andarray
are now optional by default when used as property type. See #906 - [BREAKING]
postProcessSnapshot
can no longer be declared as action, but, likepreProcessSnapshot
, needs to be defined on the type rather than on the instance. - [BREAKING]
types.union
is now eager, which means that if multiple valid types for a value are encountered, the first valid type is picked, rather then throwing. #907 / #804,dispatcher
param => option,
- [BREAKING] MobX-state-tree now requires at least TypeScript 2.8 when using MST with typescript. The type system has been revamped, and should now be a lot more accurate, especially concerning snapshot types.
- [BREAKING]
map.put
will now return the inserted node, rather than the map itself. This makes it easier to find objects for which the identifier is not known upfront. See #766 by k-g-a - [BREAKING] The order of firing hooks when instantiating has slighlty changed, as the
afterCreate
hook will now only be fired upon instantiation of the tree node, which now happens lazily (on first read / action). The internal order in which hooks are fired within a single node has remained the same. See #845 for details - Significantly improved the performance of constructing MST trees. Significantly reduced the memory footprint of MST. Big shoutout to the relentless effort by k-g-a to optimize all the things! See #845 for details.
- Introduced
setLivelynessChecking("warn" | "ignore" | "error")
, this can be used to customize how MST should act when one tries to read or write to a node that has already been removed from the tree. The default behavior iswarn
. - Improved the overloads of
model.compose
, see #892 by t49tran - Fixed issue where computed properties based on
getPath
could return stale results, fixes #917 - Fixed issue where onAction middleware threw on dead nodes when attachAfter option was used
- Fixed several issues with maps and numeric identifiers, such as #884 and #826
types.identifier(types.number)
=>types.identifierNumber
types.identifier()
andtypes.identifier(types.string) =>
types.identifier`types.frozen
=>types.frozen()
types.maybe(x)
=>types.maybeNull(x)
postProcessSnapshot
should now be declared on the type instead of as action
- Added support for MobX 5. Initiative by @jeffberry through #868. Please note that there are JavaScript engine restrictions for MobX 5 (no Internet Explorer, or React Native Android). If you need to target those versions please keep using MobX 4 as peer dependency (MST is compatible with both)
- Reduced memory footprint with ~10-20%, by k-g-a through #872
- Fixed issue where undo manager was not working correctly for non-root stores, by marcofugaro trough #875
- Fixed issue where default values of
types.frozen
where not applied correctly after apply snapshot. #842 by SirbyAlive. Fixes #643 - Fixed issue where empty patch sets resulted in in unnecessary history items. #838 by chemitaxis. Fixes #837
flow
s of destroyed nodes can no 'safely' resume. #798 by Bnaya. Fixes #792- Made sure the type
Snapshot
is exposed. #821 by dsabanin - Fix: the function parameter was incorrectly typed as non-optional. #851 by abruzzihraig
- It is now possible to get the snapshot of a node without triggering the
postProcessSnapshot
hook. See #745 for details. By @robinfehr - Introduced
getParentOfType
andhasParentOfType
. See #767 by @k-g-a - Fixed issue where running
typeCheck
accidentally logged typecheck errors to the console. Fixes #781
- Removed accidental dependency on mobx
- Fixed issue where middleware that changed arguments wasn't properly picked up. See #732 by @robinfehr. Fixes #731
- Fixed reassigning to a custom type from a different type in a union silently failing. See #737 by @univerio. Fixes #736
- Fixed typings issue with TypeScript 2.8. See #740 by @bnaya.
- Fixed undo manager apply grouped patches in the wrong order. See #755 by @robinfehr. Fixes #754
- Fixed bidirectional references from nodes to nodes, see #728 by @robinfehr
joinJsonPath
andsplitJsonPath
are now exposed as utilities, see #724 by @jjrv- Several documentation and example fixes
- Fixed typings for maps of maps #704 by @xaviergonz
- Fixed dependency issue in
mst-middlewares
package
Breaking changes
- MobX-state-tree now requires MobX 4.0 or higher
- Identifiers are now internally always normalized to strings. This also means that adding an object with an number identifier to an observable map, it should still be requested back as string. In general, we recommend to always use string based identifiers to avoid confusion.
Features
- It is now possible to create custom primitive(like) types! Implements #673 through #689
getIdentifier
is now exposed as function, to get the identifier of a model instance (if any). Fixes #674 through #678 by TimHollies- Writing middleware has slightly changed, to make it less error prone and more explicit whether a middleware chain should be aborted. For details, see #675 by Robin Fehr
- It is now possible to configure whether attached middleware should be triggered for the built-in hooks / operations. #653 by Robin Fehr
- We exposed an api to perform reflection on model instances. #649 by Robin Fehr
Fixes
- Fixed a bug where items in maps where not properly reconciled when the
put
operation was used. Fixed #683 and #672 through #693 - Fixed issue where trying to resolve a path would throw exceptions. Fixed #686 through #692
- In non production builds actions and views on models can now be replaced, to simplify mocking. Fixes #646 through #690
- Fixed bug where
tryResolve
could leave a node in a corrupt state. #668 by dnakov - Fixed typings for TypeScript 2.7, through #667 by Javier Gonzalez
- Several improvements to error messages
- Fixed bug where
flows
didn't properly batch their next ticks properly in actions, significantly slowing processes down. Fixes #563
- Significantly improved the undo/redo manager. The undo manager now supports groups. See #504 by @robinfehr! See the updated docs for more details.
- Significantly improved performance, improvements of 20% could be expected, but changes of course per case. See #553
- Implemented
actionLogger
middleware, which logs most events for async actions - Slightly changed the order in which life cycle hooks are fired.
afterAttach
will no fire first on the parent, then on the children. So, unlikeafterCreate
, inafterAttach
one can assume in `afterAttach that the parent has completely initialized.
- 1.2.0 didn't seem to be released correctly...
- Introduced customizable reference types. See the reference and identifiers section.
- Introduced
model.volatile
to more easily declare and reuse volatile instance state. Volatile state can contain arbitrary data, is shallowly observable and, like props, cannot be modified without actions. Seemodel.volatile
for more details.
- Fixed an issue where nodes where not always created correctly, see #534. Should fix #513 and #531.
- All tests are now run in both PROD and non PROD configurations, after running into some bugs that only occurred in production builds.
- Some internal optimizations have been applied (and many more will follow). Like having internal leaner node for immutable data. See #474
- A lot of minor improvements on the docs
- The concept of process (asynchronous actions) has been renamed to flows. (Mainly to avoid issues with bundlers)
- We changed to a lerna setup which allows separately distributing middleware and testing examples with more ease
- Every MST middleware is now shipped in a separate package named
mst-middlewares
. They are now written in TypeScript and fully transpiled to ES5 to avoid problems with uglifyjs in create-react-app bundling. - Introduced
createActionTrackingMiddleware
, this significantly simplifies writing middleware for common scenarios. Especially middleware that deals with asynchronous actions (flows) - Renamed
process
toflow
. Deprecatedprocess
. - BREAKING As a result some middleware event names have also been changed. If you have custom middlewares this change might affect you. Rename middleware event type prefixes starting with
process
to now start withflow
.
- Fixed nested maps + environments not working correctly, #447 by @xaviergonz
- Improved typescript typings for enumerations, up to 50 values are now supported #424 by @danielduwaer
- Introduced
modelType.extend
which allows creating views and actions with shared state.
- Added the middlewares
atomic
and typesTimeTraveller
,UndoManager
. Check out the docs! - Introduced
createActionTrackingMiddleware
to simplify the creation of middleware that support complex async processes - exposed
typecheck(type, value)
as public api (will ignore environment flags)
getEnv
will return an empty object instead of throwing when a tree was initialized without environment- Fixed issue where patches generated for nested maps were incorrect (#396)
- Fixed the escaping of (back)slashes in JSON paths (#405)
- Improved the algorithm that reconcile items in an array (#384)
- Assigning a node that has an environment to a parent is now allowed, as long as the environment is strictly the same (#387)
- Many minor documentation improvements. Thanks everybody who created a PR!
No changes
- BREAKING The redux utilities are no longer part of the core package, but need to be imported from
mobx-state-tree/middleware/redux
.
- BREAKING
onAction
middleware no longer throws when encountering unserializable arguments. Rather, it serializes a struct like{ $MST_UNSERIALIZABLE: true, type: "someType" }
. MST Nodes are no longer automatically serialized. Rather, one should either pass 1: an id, 2: a (relative) path, 3: a snapshot - BREAKING
revertPatch
has been dropped.IReversableJsonPatch
is no longer exposed, instead use the inverse patches generated byonPatch
- BREAKING some middleware events have been renamed:
process_yield
->process_resume
,process_yield_error
->process_resume_error
, to make it less confusing how these events relate toyield
statements. - BREAKING patchRecorder's field
patches
has been renamed torawPatches,
cleanPatchesto
patches, and
inversePatches` was added.
- Introduced
decorate(middleware, action)
to easily attach middleware to a specific action - Handlers passed to
onPatch(handler: (patch, inversePatch) => void)
now receive as second argument the inverse patch of the emitted patch onAction
lister now supports anattachAfter
parameter- Middleware events now also contain
parentId
(id of the causing action,0
if none) andtree
(the root of context)
- ReduxDevTools connection is no longer one step behind #287
- Middleware is no longer run as part of the transaction of the targeted action
- Fixed representation of
union
types in error messages
- BREAKISH Redefining lifecycle hooks will now automatically compose them, implements #252
- Added dev-only checks, typecheck will be performed only in dev-mode and top-level API-calls will be checked.
- The internal types
IMiddleWareEvent
,IMiddlewareEventType
,ISerializedActionCall
are now exposed (fixes #315)
- Object model instances no longer share a prototype.
- Removed accidental dependency on the codemod
- BREAKING the syntax to define model types has been updated. See the updated docs or the original proposal:#282, but no worries, theres a codemod! :D
- BREAKING
preProcessSnapshot
hook is no longer a normal hook that can be defined as action. Instead, it should be defined on the type usingtypes.model(...).preProcessSnapshot(value => value)
- BREAKING Asynchronous process should now be defined using
process
. See this example or the asynchronous action docs.
How to run the codemod?
The codemod is provided as npm package command line tool. It has been written using the TypeScript parser, so it will successfully support either TS or regular JavaScript source files.
To run the codemod, you need to first install it globally by npm install -g mst-codemod-to-0.10
.
After that, the mst-codemod-to-0.10
command will be available in your command line.
To perform the codemod, you need to call in your command line mst-codemod-to-0.10
followed by the filename you want to codemod. A .bak
file with the original source will be created for backup purposes, and the file you provided will be updated to the new syntax! Have fun!
PS: You could also use npx
instead of installing the codemod globally! :)
- Asynchronous actions are now a first class concept in mobx-state-tree. See the docs
- Introduced
types.null
andtypes.undefined
- Introduced
types.enumeration(name?, options)
- Fix
note that a snapshot is compatible
when assigning a type to an optional version of itself - Fix error when deleting a non existing item from a map #255
- Now all required TypeScript interfaces are exported in the main mobx-state-tree package #256
Introduced the concept of reverse patches, see #231
- Introduced the
revertPatch
operation, that takes a patch or list of patches, and reverse applies it to the target. onPatch
now takes a second argument,includeOldValue
, defaulting tofalse
, which, if set to true, includes in the patch any value that is being overwritten as result of the patch. Setting this option to true produces patches that can be used withrevertPatch
patchRecorder
now introduces additional fields / methods to be able to reverse apply changes:patchRecorder.cleanPatches
,patchRecorder.undo
- Applying a snapshot or patches will now emit an action as well. The name of the emitted action will be
@APPLY_PATCHES
resp@APPLY_SNAPSHOT
. See #107 - Fixed issue where same Date instance could'nt be used two times in the same state tree #229
- Fixed issue with reapplying snapshots to Date field resulting in snapshot typecheck error#233
- Declaring
types.maybe(types.frozen)
will now result into an error #224 - Added support for Mobx observable arrays in type checks #221 (from alessioscalici)
- BREAKING Removed
applyPatches
andapplyActions
. UseapplyPatch
resp.applyAction
, as both will now also accept an array as argument - BREAKING
unprotect
andprotect
can only be applied at root nodes to avoid confusing scenarios Fixed #180 - Fixed #141, actions / views are no longer wrapped in dynamically generated functions for a better debugging experience
- Small improvements to typings, fixed compilation issues with TypeScript 2.4.1.
- Fixed issues where
compose
couldn't overwrite getters. #209, by @homura - Fixed CDN links in readme
- Added TodoMVC to the examples section
- Fixed issue in rollup module bundle
- Fixed issue in release script, rendering 0.8.0 useless
- BREAKING Dropped
types.extend
in favor oftypes.compose
. See #192 - Introduced the lifecycle hooks
preProcessSnapshot
andpostProcessSnapshot
. See #203 / #100 - Use rollup as bundler #196
- Introduced the concept of volatile / local state in models. See #168, or docs
- Fixed issue with types.map() with types.identifier(types.number) #191 reported by @boatkorachal
- Fixed issue with reconciler that affected types.map when node already existed at that key reported by @boatkorachal #191
- Fixed
cannot read property resolve of undefined
thanks to @cpunion for reporting, now value of dead nodes will be undefined. #186 - Fixed
[LateType] is not defined
thanks to @amir-arad for reporting, when using late as model property type #187 - Fixed
Object.freeze can only be called on Object
thanks to @ds300 for reporting, when using MST on a ReactNative environment #189 - Now the entire codebase is prettier! :D #187
- Fixed
array.remove
not working
The type system and internal administration has been refactoring, making the internals both simpler and more flexible. Things like references and identifiers are now first class types, making them much better composable. #152
- BREAKING References with a predefined lookup path are no longer supported. Instead of that, identifiers are now looked up in the entire tree. For that reasons identifiers now have to be unique in the entire tree, per type.
- BREAKING
resolve
is renamed toresolvePath
- Introduced
resolveIdentifier(type, tree, identifier)
to find objects by identifier - BREAKING
types.reference
is by default non-nullable. For nullable identifiers, usetypes.maybe(types.reference(X))
- Many, many improvements. Related open issues will be updated.
- BREAKING
isMST
is renamed toisStateTreeNode
- Fixed issue with array/maps of union types @abruzzihraig #151
- Make types.extend support computed attributes @cpunion #169
- Fixed issue with map of primitive types and applySnapshot @pioh #155
- Better type declarations for union, up to 10 supported types
- Fixed issue where arrays where not properly serialized as action argument
- Improved reporting of Type.is(), now it returns a fine grained report of why the provided value is not applicable.
[mobx-state-tree] Error while converting [{}] to AnonymousModel[]:
at path "/name" snapshot undefined is not assignable to type: string.
at path "/quantity" snapshot undefined is not assignable to type: number.
- Fixed support for
types.reference
in combination withtypes.late
, by @robinfehr
- BREAKING
types.withDefault
has been renamed totypes.optional
- BREAKING Array and map types can no longer be left out of snapshots by default. Use
optional
to make them optional in the snapshot - BREAKING Literals no longer have a default value by default (use optional + literal instead)
- BREAKING Disabled inlining type.model definitions as introduced in 0.5.1; to many subtle issues
- Improved identifier support, they are no properly propagated through utility types like
maybe
,union
etc - Fixed issue where fields where not referred back to default when a partial snapshot was provided
- Fixed #122:
types.identifier
now also accepts a subtype to override the default string type; e.g.types.identifier(types.number)
- Introduced support for lazy evaluating values in
withDefault
, useful to generate UUID's, timestamps or non-primitive default values It is now possible to define something likeRemoved in 0.6.0
const Box = types.model({
point: {
x: 10,
y: 10
}
}
Where the type of point
property is inferred to point: types.withDefault(types.model({ x: 10, y: 10}), () => ({ x: 10, y: 10 }))
- ** BREAKING ** protection is now enabled by default (#101)
- ** BREAKING ** it is no longer possible to read values from a dead object. Except through
getSnapshot
orclone
(#102) - ** BREAKING **
types.recursive
has been removed in favor oftypes.late
- Introduced
unprotect
, to disable protection mode for a certain instance. Useful inafterCreate
hooks - Introduced
types.late
. Usage:types.late(() => typeDefinition)
. Can be used for circular / recursive type definitions, even across files. Seetest/circular(1|2).ts
for an example (#74)
BREAKING types.model
no requires 2 parameters to define a model. The first parameter defines the properties, derived values and view functions. The second argument is used to define the actions. For example:
const Todo = types.model("Todo", {
done: types.boolean,
toggle() {
this.done = !this.done
}
})
Now should be defined as:
const Todo = types.model(
"Todo",
{
done: types.boolean
},
{
toggle() {
this.done = !this.done
}
}
)
It is still possible to define functions on the first object. However, those functions are not considered to be actions, but views. They are not allowed to modify values, but instead should produce a new value themselves.
- Introduced lifecycle hooks
afterCreate
,afterAttach
,beforeDetach
,beforeDestroy
, implements #76 - Introduced the convenience method
addDisposer(this, cb)
that can be used to easily destruct reactions etc. which are set up inafterCreate
. See #76
- Fix: actions where not bound automatically
- Improved and simplified the reconciliation mechanism, fixed many edge cases
- Improved the reference mechanism, fixed many edge cases
- Improved performance
- (re) introduced the concept of environments, which can be passed as second argument to
.create
, and picked up usinggetEnv
- Removed
primitive
type, use a more specific type instead - Improved typescript typings of snapshots
- Added
depth
parameter togetParent
andhasParent
- Separated the concepts of middleware and serializable actions. It is now possible to intercept, modify actions etc through
addMiddleWare
.onAction
now uses middleware, if it is used, all parameters of actions should be serializable!
- Introduced the concept of liveliness; if nodes are removed from the the tree because they are replaced by some other value, they will be marked as "died". This should help to early signal when people hold on to references that are not part of the tree anymore. To explicitly remove an node from a tree, with the intent to spawn a new state tree from it, use
detach
. - Introduced the convenience method
destroy
to remove a model from it's parent and mark it as dead. - Introduced the concept of protected trees. If a tree is protected using
protect
, it can only be modified through action, and not by mutating it directly anymore.
- Introduced .Type and .SnapshotType to be used with TypeScript to get the type for a model
- Renamed
createFactory
totypes.model
(breaking!) - Renamed
composeFactory
totypes.extend
(breaking!) - Actions should now be declared as
name(params) { body }
, instead ofname: action(function (params) { body})
(breaking!) - Models are no longer constructed by invoking the factory as function, but by calling
factory.create
(breaking!) - Introduced
identifier
- Introduced / improved
reference
- Greatly improved typescript support, type inference etc. However there are still limitations as the full typesystem of MST cannot be expressed in TypeScript. Especially concerning the type of snapshots and the possibility to use snapshots as first class value.