--- title: "Function: deepCloneAndModify" description: Recursively change a type 'string' or 'number' generically via an applied function. pubDate: 2026-08-17T09:53:44.266Z antora: editUrl: https://github.com/couchbaselabs/docs-devex/edit/release/8.0/modules/eventing/pages/eventing-handler-deepCloneAndModify.adoc xref: xref:server:eventing:eventing-handler-deepCloneAndModify.adoc[] --- [Consult the llms.txt file for a full list of contents](/llms.txt) [View original HTML](/server/current/eventing/eventing-handler-deepCloneAndModify.html) # Function: deepCloneAndModify **Goal**: Recursively change a type 'string' or 'number' generically via an applied function. * This function **deepCloneAndModify** will recursively convert a given JavaScript type by applying a function * The sample applies **convertStrToEpoch** and copies the behavior of the sample dateToEpochConversion. * Requires Eventing Storage (or metadata collection) and a "source" collection. * Will operate on all documents where doc.type === "my\_data\_type". * deepCloneAndModify * Input Data/Mutation * Output Data/Mutation ```javascript // To run configure the settings for this Function, deepCloneAndModify, as follows: // // Version 7.1+ // "Function Scope" // *.* (or try bulk.data if non-privileged) // Version 7.0+ // "Listen to Location" // bulk.data.source // "Eventing Storage" // rr100.eventing.metadata // Binding(s) // 1. "binding type", "alias name...", "bucket.scope.collection", "Access" // "bucket alias", "src_col", "bulk.data.source", "read and write" // // Version 6.X // "Source Bucket" // source // "MetaData Bucket" // metadata // Binding(s) // 1. "binding type", "alias name...", "bucket", "Access" // "bucket alias", "src_col", "source", "read and write" function convertStrToEpoch(key, val, control) { // We want to convert string dates to a Epoch tstamp, first we utilize // a regex to filter, then if that passes we use Date.parse(..) // to convert string to numeric timestamps, finally if the last argument // is 'true' then add a suffix of "_ms" or "_sec" to the field name. // Date.parse("2009/06/29 13:30:10", "yyyy/MM/dd HH:mm:ss"); // Date.parse("2020-06-24 09.55.22 -07:00", "yyyy-MM-dd HH:mm:ss Z"); // uses a self explanatory control document as follows: // var control = [ // { "regx": /^\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d.\d+$/g, "millis": true, "rename": true }, // { "regx": /^\d\d\d\d\/\d\d\/\d\d \d\d:\d\d:\d\d$/g, "millis": false, "rename": true } // ]; for (var i = 0; i < control.length; i++) { var regxres = val.match(control[i].regx); if (regxres !== null) { var dt = Date.parse(val); if (dt && dt !== null && !isNaN(dt)) { var suffix = ""; var epochMs = dt // .getTime(); if (key !== "" && control[i].rename) { if (control[i].millis) { suffix = "_ms"; } else { suffix = "_sec"; } } if (control[i].millis) { val = epochMs; } else { val = Math.round(epochMs / 1000); } return { "key": key + suffix, "val": val, "converted": true }; } } } return { "key": key, "val": val, "converted": false }; } function deepCloneAndModify(obj, control, fn, fntype) { // This does a deepCopy or deepClone but applies convertStrToEpoch where needed // process terminal strings if (obj && typeof obj === fntype) { var retval = fn("", obj, control); return retval.val; } if (!obj || typeof obj !== 'object') { return obj; } // process Object let newObj = {}; if (Array.isArray(obj)) { newObj = obj.map(item => deepCloneAndModify(item, control, fn, fntype)); } else { Object.keys(obj).forEach((k) => { var retval = { "key": k, "val": obj[k] }; if (obj[k] && typeof obj[k] === fntype) { retval = fn(k, obj[k], control); } return newObj[retval.key] = deepCloneAndModify(retval.val, control, fn, fntype); }) } return newObj; } function OnUpdate(doc, meta) { if (doc.type !== "my_data_type") return; var rename_with_ms_or_sec = true; // rename our fields // Apply four (4) different datetime search patterns across the entire document var control = [ { "regx": /^\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d.\d+$/g, "millis": true, "rename": true }, { "regx": /^\d\d\d\d\/\d\d\/\d\d \d\d:\d\d:\d\d$/g, "millis": false, "rename": true }, { "regx": /^\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d.\d+ .\d\d:\d\d$/g, "millis": false, "rename": true }, { "regx": /^\d\d\d\d\/\d\d\/\d\d \d\d:\d\d:\d\d .\d\d:\d\d$/g, "millis": true, "rename": true } ]; var newdoc = deepCloneAndModify(doc, control, convertStrToEpoch, 'string'); // alias src_col to our source collection. Since rev 6.5+ allowed to be in r/w mode src_col[meta.id] = newdoc; } ``` ```json INPUT: KEY my_data_type::1001 { "type": "my_data_type", "id": 1001, "datet1a": "2009/06/29 13:30:10", "datet1b": "2009/06/29 13:30:10", "datet1c": "2009/06/29 13:30:10 -07:00", "datet1d": "2009/06/29 13:30:10 -06:00", "datet2a": "2009-06-29 13:30:10.333", "datet2b": "2009-06-29 13:30:10.333", "datet2c": "2009-06-29 13:30:10.333 -07:00", "datet2d": "2009-06-29 13:30:10.333 -06:00", "subdoc_same_dates": { "datet1a": "2009/06/29 13:30:10", "datet1b": "2009/06/29 13:30:10", "datet1c": "2009/06/29 13:30:10 -07:00", "datet1d": "2009/06/29 13:30:10 -06:00", "datet2a": "2009-06-29 13:30:10.333", "datet2b": "2009-06-29 13:30:10.333", "datet2c": "2009-06-29 13:30:10.333 -07:00", "datet2d": "2009-06-29 13:30:10.333 -06:00", "subsubdoc_two_dates": { "datet1a": "2009/06/29 13:30:10", "datet1b": "2009/06/29 13:30:10", "dary": [ "2009/06/29 13:30:10", "2009-06-29 13:30:10.333", { "datet1a": "2009/06/29 13:30:10" } ] } } } ``` ```json UPDATED/OUTPUT: KEY my_data_type::1001 { "type": "my_data_type", "id": 1001, "datet1a_sec": 1246307410, "datet1b_sec": 1246307410, "datet1c_sec": 1246307410, "datet1d_sec": 1246303810, "datet2a_ms": 1246307410333, "datet2b_ms": 1246307410333, "datet2c_ms": 1246307410333, "datet2d_ms": 1246303810333, "subdoc_same_dates": { "datet1a_sec": 1246307410, "datet1b_sec": 1246307410, "datet1c_sec": 1246307410, "datet1d_sec": 1246303810, "datet2a_ms": 1246307410333, "datet2b_ms": 1246307410333, "datet2c_ms": 1246307410333, "datet2d_ms": 1246303810333, "subsubdoc_two_dates": { "datet1a_sec": 1246307410, "datet1b_sec": 1246307410, "dary": [ 1246307410, 1246307410333, { "datet1a_sec": 1246307410 } ] } } } ```