Writing To Stores

This guide shows you how to write data to a Store.

A Store has two types of data in it: keyed values ('Values'), and tabular data ('Tables').

Values are just Id/Value pairs. Tables on the other hand, have a simple hierarchical structure:

• The Store's Tables object contains a number of Table objects.
• Each Table contains a number of Row objects.
• Each Row contains a number of Cell objects.

Once you have created a Store, you can write data to it with one of its setter methods, according to the level of the hierarchy that you want to set.

For example, you can set the data for the keyed value structure of Store with the setValues method:

const store = createStore();
store.setValues({employees: 3, open: true});

Similarly, you can set the data for the tabular structure of Store with the setTables method:

store.setTables({pets: {fido: {species: 'dog'}}});

Hopefully self-evidently, this sets the Store to have two Values (employees and open, which are 3 and true respectively). It also has one Table object (called pets), containing one Row object (called fido), containing one Cell object (called species and with the string value dog):

console.log(store.getValues());
// -> {employees: 3, open: true}

console.log(store.getTables());
// -> {pets: {fido: {species: 'dog'}}}

You can also alter Store data at different granularities with the setValue method, the setTable method, the setRow method, and the setCell method:

store.setValue('employees', 4);
console.log(store.getValues());
// -> {employees: 4, open: true}

store.setTable('species', {dog: {price: 5}});
console.log(store.getTables());
// -> {pets: {fido: {species: 'dog'}}, species: {dog: {price: 5}}}

store.setRow('species', 'cat', {price: 4});
console.log(store.getTables());
// -> {pets: {fido: {species: 'dog'}}, species: {dog: {price: 5}, cat: {price: 4}}}

store.setCell('pets', 'fido', 'color', 'brown');
console.log(store.getTables());
// -> {pets: {fido: {species: 'dog', color: 'brown'}}, species: {dog: {price: 5}, cat: {price: 4}}}

The data in a Value or a Cell can be a string, a number, or a boolean type.

It's worth mentioning here that there are two extra methods to manipulate Row objects. The addRow method is like the setRow method but automatically assigns it a new unique Id. And the setPartialRow method lets you update multiple Cell values in a Row without affecting the others. (setPartialValues does the same for Values.)

Deleting Data

There are dedicated deletion methods (again, for each level of granularity), such as the delValue method, the delTable method, the delRow method, and the delCell method. For example:

store.delValue('employees');
console.log(store.getValues());
// -> {open: true}

store.delTable('species');
console.log(store.getTables());
// -> {pets: {fido: {species: 'dog', color: 'brown'}}}

Deletions are also implied when you set an object that omits something that existed before:

console.log(store.getTables());
// -> {pets: {fido: {species: 'dog', color: 'brown'}}}

store.setRow('pets', 'fido', {species: 'dog'});
console.log(store.getTables());
// -> {pets: {fido: {species: 'dog'}}}
// The `color` Cell has been deleted.

Table and Row objects cannot be empty - if they are, they are removed - which leads to a cascading effect when you remove the final child of a parent object:

store.delCell('pets', 'fido', 'species');
console.log(store.getTables());
// -> {}
// The `fido` Row and `pets` Table have been recursively deleted.

Summary

That's a quick overview on how to write data to a Store. But of course you want to get it out again too!

In the examples above, we've used the getValues method and the getTables method to get a view into the data in the Store. Unsurprisingly, you can also use more granular methods to get data out - for which we proceed to the Reading From Stores guide.