How to create an array tree based on path-style values? - php

Question

I have a problem with multidimensional data arrays. I have a data array like this:
[
[
"name" => "netSnmp",
"oid" => "1.3.6.1.4.1.8072"
"status" => "current"
], [
"name" => "netSnmpObjects",
"oid" => "1.3.6.1.4.1.8072.1"
], [
"name" => "netSnmpEnumerations",
"oid" => "1.3.6.1.4.1.8072.3"
], [
"name" => "netSnmpModuleIDs",
"oid" => "1.3.6.1.4.1.8072.3.1"
], [
"name" => "netSnmpAgentOIDs",
"oid" => "1.3.6.1.4.1.8072.3.2"
], [
"name" => "netSnmpDomains",
"oid" => "1.3.6.1.4.1.8072.3.3"
], [
"name" => "netSnmpNotificationPrefix",
"oid" => "1.3.6.1.4.1.8072.4"
], [
"name" => "netSnmpNotifications",
"oid" => "1.3.6.1.4.1.8072.4.0"
], [
"name" => "netSnmpNotificationObjects",
"oid" => "1.3.6.1.4.1.8072.4.1"
]
]
I am looking for a simple way to create an array tree, based on the oid value from the array above. Those oid values are a dot-separated path. The more parts, the deeper in the final tree the corresponding item should be put.
The desired output:
[
"text" => "netSnmp",
"oid" => "1.3.6.1.4.1.8072",
"nodes" => [
[
"oid" => "1.3.6.1.4.1.8072.1",
"text" => "netSnmpObjects"
], [
"oid" => "1.3.6.1.4.1.8072.3",
"text" => "netSnmpEnumerations",
"nodes" => [
[
"text" => "netSnmpModuleIDs",
"oid" => "1.3.6.1.4.1.8072.3.1"
], [
"text" => "netSnmpAgentOIDs",
"oid" => "1.3.6.1.4.1.8072.3.2"
], [
"text" => "netSnmpDomains",
"oid" => "1.3.6.1.4.1.8072.3.3"
]
]
], [
"oid" => "1.3.6.1.4.1.8072.4",
"text" => "netSnmpNotificationPrefix"
"nodes" => [
[
"text" => "netSnmpNotifications",
"oid" => "1.3.6.1.4.1.8072.4.0"
], [
"text" => "netSnmpNotificationObjects",
"oid" => "1.3.6.1.4.1.8072.4.1"
]
]
]
]
]
Any idea how I can solve it?

Answer 1

You can key your data by oid in a new associated array: that way you can look up a certain parent key in a fast way.
Then it is just a matter of getting the parent key of a any given key (chopping off the final dot-separated part) and see where you have it in your new associated array, and then appending it to its nodes array.
Here is a function that does that:
function makeTree($arr) {
$keyed = [];
foreach ($arr as $item) $keyed[$item["oid"]] = $item;
$root = null;
foreach ($keyed as &$item) {
$key = $item["oid"];
$parent = substr($key, 0, strrpos($key, "."));
if (isset($keyed[$parent])) {
$keyed[$parent]["nodes"][] =& $item;
} else {
$root = $key;
}
}
return $keyed[$root];
}
You can run it like this on your sample data:
$arr = [
[
"name" => "netSnmp",
"oid" => "1.3.6.1.4.1.8072",
"status" => "current"
], [
"name" => "netSnmpObjects",
"oid" => "1.3.6.1.4.1.8072.1"
], [
"name" => "netSnmpEnumerations",
"oid" => "1.3.6.1.4.1.8072.3"
], [
"name" => "netSnmpModuleIDs",
"oid" => "1.3.6.1.4.1.8072.3.1"
], [
"name" => "netSnmpAgentOIDs",
"oid" => "1.3.6.1.4.1.8072.3.2"
], [
"name" => "netSnmpDomains",
"oid" => "1.3.6.1.4.1.8072.3.3"
], [
"name" => "netSnmpNotificationPrefix",
"oid" => "1.3.6.1.4.1.8072.4"
], [
"name" => "netSnmpNotifications",
"oid" => "1.3.6.1.4.1.8072.4.0"
], [
"name" => "netSnmpNotificationObjects",
"oid" => "1.3.6.1.4.1.8072.4.1"
]
];
$result = makeTree($arr);
print_r($result);