Function syncExpression

syncExpression<T, A>(modelConstructor, conditionProducer): Promise<{
conditionProducer: ConditionProducer<T, A>;
modelConstructor: PersistentModelConstructor<T>;
}>
Build an expression that can be used to filter which items of a given Model are synchronized down from the GraphQL service. E.g.,
```
import { DataStore, syncExpression } from 'aws-amplify/datastore';
import { Post, Comment } from './models';


DataStore.configure({
    syncExpressions: [
        syncExpression(Post, () => {
            return (post) => post.rating.gt(5);
        }),
        syncExpression(Comment, () => {
            return (comment) => comment.status.eq('active');
        })
    ]
});
```
When DataStore starts syncing, only Posts with rating > 5 and Comments with status === 'active' will be synced down to the user's local store.
Type Parameters
- T extends Readonly<Record<string, any>>
- A extends Option<T>
Parameters
- modelConstructor: PersistentModelConstructor<T>
  The Model from the schema.
- conditionProducer: ConditionProducer<T, A>
  A function that builds a condition object that can describe how to filter the model.
Returns Promise<{
conditionProducer: ConditionProducer<T, A>;
modelConstructor: PersistentModelConstructor<T>;
}>
An sync expression object that can be attached to the DataStore syncExpressions configuration property.