Using Node.js with Caché - InterSystems Documentation

previous_node()
Asynchronous
Parameters
mydata.previous(node, callback_function);
• node — the global node to be accessed.
• callback_function — a function of the form function(error, result){} used to return results
asynchronously (see “Synchronous vs. Asynchronous cache.node Methods”).
Example 1 (Synchronous)
result = mydata.previous_node({global: "Customer", subscripts: ["z"]},
Result:
{global: "Customer", subscripts: [3], data: "Jane Smith", defined: 1}}
Example 2 (Synchronous)
result = mydata.next_node({global: "Customer", subscripts: [2]},
Result:
{
}
global: "Customer",
subscripts: [1, "address"],
data: "Banstead",
defined: 1
Example 3 (Asynchronous)
mydata.previous_node(
{global: "Customer", subscripts: [1]},
function(error, result) { // callback code }
);
Result:
{global: "Customer", defined: 0}}
Example 4 (Parse Global)
key = {global: "Customer", subscripts: ["z"]};
while ((key = user.previous_node(key)).defined) {
console.log(JSON.stringify(key, null, '\t'));
}
Result:
{
}
{
}
{
}
{
global: "Customer",
subscripts: [3],
data: "Jane Smith",
defined: 1
global: "Customer",
subscripts: [2],
data: "Rob Tweed",
defined: 1
global: "Customer",
subscripts: [1, "address"],
data: "Banstead",
defined: 1
Using Node.js with Caché 29