filter

Gets or sets the filter expression for DataSource. If a filter expression is specified during initialization, this property contains the initial filter expression.

var dataSource = new shield.DataSource({
    filter: { path: "category", filter: "eq", value: 4 }
});

dataSource.filter.value = 5;
dataSource.read().then(function (data) {
    //data is filtered by category values equal to 5
});