writing-handlebars

Writing Handlebars Expressions

Handlebars is Celigo's template language for embedding dynamic values into resource configurations. Any string field that the platform evaluates at runtime can contain Handlebars expressions.

Concerns when writing Handlebars:

• Context -- where the expression runs determines what data is available and how output is treated
• Braces -- double {{ }} vs triple {{{ }}} controls output escaping
• Field access -- record. prefix in all contexts (AFE 2.0), @root for job/settings/connection, bracket notation for special characters
• Helpers -- 79 custom helpers for math, string manipulation, dates, encoding, regex, and more
• Block helpers -- #each, #if, #compare, #with for iteration and conditional logic
• Date/time -- moment.js format tokens with timezone support

Used across exports, imports, mappings, output filters, and APIs.

Where Handlebars Are Used

Mapping extracts

In import mappings[].extract fields, Handlebars concatenates, transforms, or conditionally selects values. The context is the current record.

HTTP request templates

Export and import http blocks use Handlebars in relativeURI, body, headers, and postBody. Triple braces are essential to avoid HTML encoding of query parameters and JSON.

RDBMS SQL queries

SQL queries in rdbms.query use Handlebars with the mandatory record. prefix. Triple braces prevent encoding of SQL-significant characters like commas and quotes. For full SQL patterns (MERGE, upsert, bulk operations, dialect differences), see writing-sql.

Output filters

Expression-based filters on exports use Handlebars to evaluate whether a record passes through or gets skipped.

File paths and names

Dynamic file names in FTP/S3 exports and imports use Handlebars for timestamps and record-derived values.

Delta tokens

Platform-injected variables like {{{lastExportDateTime}}} provide the last successful export timestamp for incremental syncs. These are not record fields -- the platform injects them at runtime into the export's HTTP/query context only.

Quick Reference

Context Decision Matrix (AFE 2.0)

All contexts use record. prefix to access the current record's fields (AFE 2.0). Do NOT use bare field names, data.field, or data.0.field -- those are deprecated AFE 1.0 patterns. Exception: Mapper 1.0 (Salesforce/NetSuite) uses bare field names without record. prefix.

Additional context objects available via @root:

When one-to-many grouping is configured, the data shape changes to batch_of_records -- iterate with {{#each batch_of_records}} to access individual records.

Key Syntax

• {{{triple-braces}}} -- raw output, no escaping. Use for URIs, SQL, JSON bodies, file paths -- anywhere commas, quotes, or ampersands matter. In RDBMS, triple braces output the raw value (value); double braces wrap in single quotes ('value'). Prefer triple and add literal quotes explicitly where needed.
• {{double-braces}} -- context-dependent formatting. In RDBMS adds single quotes around the value. In URLs, URL-encodes. Use triple braces for explicit control.
• Always use record. prefix (AFE 2.0) -- {{{record.fieldName}}} in all contexts, never bare {{{fieldName}}} or {{{data.fieldName}}} (AFE 1.0). Nested fields: {{{record.properties.email}}}.
• Exception: Mapper 1.0 (Salesforce/NetSuite) -- uses bare field names without record. prefix. This is the only context where bare field references are correct.

Related Skills

• configuring-exports > Quick Reference -- export adaptor types, delta sync setup, output filters
• configuring-imports > Quick Reference -- import adaptor types, operation modes, mapping systems
• writing-mappings > Quick Reference -- Mapper 2.0 fields, lookups, conditional mappings

Syntax Fundamentals

Braces

Field access

Subexpressions (nesting helpers)

Use () to nest one helper's output as input to another. The inner helper evaluates first:

{{uppercase (split record.fullName " " 0)}}              -- split then uppercase the first word
{{{base64Encode (join ":" record.user record.pass)}}}    -- join then encode
{{#compare (add record.qty 1) ">" "100"}}...{{/compare}} -- add then compare
{{#each (after record.tags 3)}}...{{/each}}              -- slice then iterate

Subexpressions can be nested multiple levels deep. Each () resolves inside-out.

Block helpers

• {{#each record.items}}...{{/each}} -- iterate array or object
• {{#if record.active}}...{{else}}...{{/if}} -- conditional
• {{#compare val1 "==" val2}}...{{/compare}} -- comparison (==, ===, !=, !==, <, >, <=, >=)
• {{#with record.address}}...{{/with}} -- change context scope

Date/time formatting

Uses moment.js tokens. Always use triple braces for date output.

Common tokens: YYYY (4-digit year), MM (2-digit month), DD (2-digit day), HH (24h hour), mm (minute), ss (second), SSS (millisecond), Z (timezone offset), X (Unix seconds), x (Unix milliseconds).

Timezone: pass as third argument -- {{{dateFormat "YYYY-MM-DD" record.date "US/Eastern"}}}.

Date arithmetic

dateAdd works in milliseconds:

• 1 hour = 3,600,000
• 1 day = 86,400,000
• 7 days = 604,800,000

Runtime Context at Each Stage

What {{record.X}} or {{settings.Y}} actually resolves to depends on which bubble the expression runs in. The shapes below were captured by setting body: "{{{jsonSerialize this}}}" on import/lookup bubbles and echoing through a mirror endpoint — they represent exactly what's available at runtime.

Import bubble (HTTPImport, NetSuiteDistributedImport, etc.)

Body templates and Handlebars in mappings[].extract run per-record with this context:

{
  "0": { ...the record at batch index 0, with mapped fields... },   // per-record
  "data": [ ...array of all records in this page, post-mapping... ],

Lookup bubble (HTTPExport with isLookup: true)

Lookup request templates run per-record with a different shape:

Export bubble (source generator)

Export URI templates and delta tokens have a minimal context — the platform injects {{{lastExportDateTime}}}, {{{currentExportDateTime}}}, plus settings and connection. No record. context exists yet (records haven't been fetched).

Key differences between import and lookup contexts

How to rediscover the shape for any bubble

Set the body on an HTTP import or lookup to {{{jsonSerialize this}}} and point it at an echo endpoint (integrator.io's /v1/mirror works). Enable flow execution logging, run the flow, and inspect the apiCall.response.body — it's a copy of what you sent, which is the full runtime context. This works for any bubble whose adaptor sends an HTTP body.

How to Write a Handlebars Expression

1. Identify the context

Where the expression runs determines what data is available. In AFE 2.0, all contexts use record. to access the current record:

Other context objects (job, settings, connection) are accessible via @root -- e.g., {{@root.connection.http.encrypted.apiKey}}.

When one-to-many grouping is active, the shape is batch_of_records and you must iterate: {{#each batch_of_records}}{{record.field}}{{/each}}.

2. Know the data shape

Before writing any expression, inspect what the input data looks like:

3. Choose the right braces

• Default to {{{ }}} (triple) for HTTP bodies, SQL, URIs, file paths
• Use {{ }} (double) only in mapping extracts and display text where HTML escaping is acceptable
• When in doubt, use triple -- raw output never breaks SQL or JSON; HTML-escaped output can

4. Find the right helper

See the helper index for all 79 custom helpers. Key categories:

• Math -- abs, add, subtract, multiply, divide, modulo, ceil, floor, round, sum, avg, random, toFixed, toExponential, toPrecision
• String -- uppercase, lowercase, capitalize, capitalizeAll, camelcase, pascalcase, snakecase, dashcase, dotcase, pathcase, sentence, trim, trimLeft, trimRight, padLeft, padRight, replace, replacefirst, removefirst, chop, truncateWords, sanitize, split, join, reverse, occurrences, substring
• Array -- after, before, first, last, reverse, sort, unique, pluck, arrayify, lookup, getValue, sum
• Date/time -- dateFormat, dateAdd, timestamp
• Encoding -- base64Encode, base64Decode, htmlEncode, htmlDecode, jsonEncode, jsonParse, jsonSerialize, encodeURI, decodeURI, stripProtocol, stripQuerystring
• Regex -- regexMatch, regexReplace, regexSearch
• Auth/crypto -- hash, hmac, aws4
• Type/logic -- typeOf, eq, isTruthy, isFalsey, hasOwn, hasNoItems, compare
• Format -- addCommas, bytes, ordinalize
• Block helpers -- #each, #if, #compare, #contains, #filter, #and, #or, #not, #unless, #with, #some, #startsWith, #inArray, #isEmpty

5. Test the expression

Common Patterns

JSON comma separation in HTTP body templates

Avoid trailing commas when building JSON arrays:

Grouped data access (one-to-many / batch_of_records)

When one-to-many grouping is configured, the data shape becomes batch_of_records. Iterate to access individual records:

Conditional field with fallback

Nested iteration with parent context

SQL IN clause from list variable

Build by a preSavePage hook (which can inject fields into the record), rendered with triple braces:

JavaScript-to-Handlebars equivalents

Pre-Submit Checklist

Before finalizing any Handlebars expression, verify each item:

• Prefer triple braces {{{ }}}. Double braces apply context-dependent formatting -- in RDBMS they wrap values in single quotes ('value'), in URLs they URL-encode. Use triple braces for explicit control and add literal quotes where needed.
• record. prefix everywhere (AFE 2.0). All contexts use record.fieldName -- mappings, HTTP bodies, SQL, filters. Never use bare fieldName, data.fieldName, or data.0.fieldName (AFE 1.0). Exception: Mapper 1.0 (Salesforce/NetSuite) uses bare field names.
• lastExportDateTime only in export context. This platform-injected variable is available in the export's HTTP/query context for delta syncs only -- not in mappings or import templates.
• dateAdd values in milliseconds. 1 day = 86,400,000. Not seconds, not hours.
• #each context shifts. Inside {{#each}}, this is the current item. Use ../ for parent or @root for top-level fields.
• Missing fields fail silently. Handlebars outputs empty string for undefined fields. Guard with {{#if field}} when the downstream system rejects empty values.
• Bracket notation for special characters. Field names with spaces, dots, or hyphens need record.[Field Name] syntax.
• compare is string-based. {{#compare "9" ">" "10"}} is TRUE (lexicographic). Convert values first or use strict operators.
• Test with real data. Run celigo exports invoke or celigo imports invoke to verify the expression renders correctly with actual records.

Gotchas

1. Double braces apply auto-formatting. {{ }} adds context-dependent formatting -- in RDBMS it wraps values in single quotes ('value'), in URLs it URL-encodes. This can corrupt SQL queries and JSON bodies. Prefer {{{ }}} (raw output) and add literal quotes explicitly where needed.
2. Always use record. prefix (AFE 2.0). Use {{{record.fieldName}}}, not {{{fieldName}}} or {{{data.fieldName}}}. The record. prefix applies in all contexts -- mappings, HTTP, SQL, filters. Bare field names and data. prefix are deprecated AFE 1.0 syntax.
3. lastExportDateTime is platform-injected. It exists only in the export's HTTP/query context for delta syncs -- not available in mappings or import templates.
4. compare does string comparison. {{#compare "9" ">" "10"}} is TRUE because "9" > "1" lexicographically. Use the strict equality operators or convert values first.
5. Nested #each changes context. Inside {{#each record.items}}, this is the current item, not the record. Use ../ to reach the parent or @root for the top-level context.
6. dateAdd uses milliseconds, not seconds. Adding 1 day is 86400000, not 86400. A common mistake that produces dates seconds in the future instead of days.
7. regexMatch returns the match string; regexSearch returns the position. Don't confuse them -- regexSearch returns a number (0-indexed position), not the matched text.
8. Raw blocks {{{{ }}}} output literal Handlebars syntax. They are for escaping {{ }} in output, not for "extra raw" rendering.
9. Missing fields produce empty string silently. No error on missing fields -- Handlebars outputs nothing. Use {{#if field}} to guard when the downstream system rejects empty values.
10. jsonEncode wraps a single value, not a whole body. It adds quotes and escapes special characters for embedding one field in a JSON string. Don't wrap the entire template in it.

Common Errors