106 lines
4.3 KiB
Markdown
106 lines
4.3 KiB
Markdown
{.section-title.accent.text-primary}
|
|
# API state related functions Reference
|
|
|
|
### Saving / loading state
|
|
|
|
The `WA.state` functions allow you to easily share a common state between all the players in a given room.
|
|
Moreover, `WA.state` functions can be used to persist this state across reloads.
|
|
|
|
```
|
|
WA.state.saveVariable(key : string, data : unknown): void
|
|
WA.state.loadVariable(key : string) : unknown
|
|
WA.state.onVariableChange(key : string).subscribe((data: unknown) => {}) : Subscription
|
|
WA.state.[any property]: unknown
|
|
```
|
|
|
|
These methods and properties can be used to save, load and track changes in variables related to the current room.
|
|
|
|
Variables stored in `WA.state` can be any value that is serializable in JSON.
|
|
|
|
Please refrain from storing large amounts of data in a room. Those functions are typically useful for saving or restoring
|
|
configuration / metadata.
|
|
|
|
{.alert.alert-warning}
|
|
We are in the process of fine-tuning variables, and we will eventually put limits on the maximum size a variable can hold. We will also put limits on the number of calls you can make to saving variables, so don't change the value of a variable every 10ms, this will fail in the future.
|
|
|
|
|
|
Example :
|
|
```javascript
|
|
WA.state.saveVariable('config', {
|
|
'bottomExitUrl': '/@/org/world/castle',
|
|
'topExitUrl': '/@/org/world/tower',
|
|
'enableBirdSound': true
|
|
}).catch(e => console.error('Something went wrong while saving variable', e));
|
|
//...
|
|
let config = WA.state.loadVariable('config');
|
|
```
|
|
|
|
You can use the shortcut properties to load and save variables. The code above is similar to:
|
|
|
|
```javascript
|
|
WA.state.config = {
|
|
'bottomExitUrl': '/@/org/world/castle',
|
|
'topExitUrl': '/@/org/world/tower',
|
|
'enableBirdSound': true
|
|
};
|
|
|
|
//...
|
|
let config = WA.state.config;
|
|
```
|
|
|
|
Note: `saveVariable` returns a promise that will fail in case the variable cannot be saved. This
|
|
can happen if your user does not have the required rights (more on that in the next chapter).
|
|
In contrast, if you use the WA.state properties, you cannot access the promise and therefore cannot
|
|
know for sure if your variable was properly saved.
|
|
|
|
If you are using Typescript, please note that the type of variables is `unknown`. This is
|
|
for security purpose, as we don't know the type of the variable. In order to use the returned value,
|
|
you will need to cast it to the correct type (or better, use a [Type guard](https://www.typescriptlang.org/docs/handbook/2/narrowing.html) to actually check at runtime
|
|
that you get the expected type).
|
|
|
|
{.alert.alert-warning}
|
|
For security reasons, the list of variables you are allowed to access and modify is **restricted** (otherwise, anyone on your map could set any data).
|
|
Variables storage is subject to an authorization process. Read below to learn more.
|
|
|
|
#### Declaring allowed keys
|
|
|
|
In order to declare allowed keys related to a room, you need to add **objects** in an "object layer" of the map.
|
|
|
|
Each object will represent a variable.
|
|
|
|
<div class="row">
|
|
<div class="col">
|
|
<img src="https://workadventu.re/img/docs/object_variable.png" class="figure-img img-fluid rounded" alt="" />
|
|
</div>
|
|
</div>
|
|
|
|
TODO: move the image in https://workadventu.re/img/docs
|
|
|
|
|
|
The name of the variable is the name of the object.
|
|
The object **type** MUST be **variable**.
|
|
|
|
You can set a default value for the object in the `default` property.
|
|
|
|
Use the `persist` property to save the state of the variable in database. If `persist` is false, the variable will stay
|
|
in the memory of the WorkAdventure servers but will be wiped out of the memory as soon as the room is empty (or if the
|
|
server restarts).
|
|
|
|
{.alert.alert-info}
|
|
Do not use `persist` for highly dynamic values that have a short life spawn.
|
|
|
|
With `readableBy` and `writableBy`, you control who can read of write in this variable. The property accepts a string
|
|
representing a "tag". Anyone having this "tag" can read/write in the variable.
|
|
|
|
{.alert.alert-warning}
|
|
`readableBy` and `writableBy` are specific to the public version of WorkAdventure because the notion of tags
|
|
is not available unless you have an "admin" server (that is not part of the self-hosted version of WorkAdventure).
|
|
|
|
Finally, the `jsonSchema` property can contain [a complete JSON schema](https://json-schema.org/) to validate the content of the variable.
|
|
Trying to set a variable to a value that is not compatible with the schema will fail.
|
|
|
|
|
|
|
|
|
|
TODO: document tracking, unsubscriber, etc...
|