ColdFusion Programming
ColdFusion programming where the logic layer holds
Most ColdFusion problems aren't platform problems — they're programming problems: concatenated queries, missing validation, logic buried in markup. Here's how we write CFML so the system stays fast, secure, and readable for years.
The platform is fine. The code is the variable.
Every "ColdFusion is slow" or "ColdFusion is insecure" story we've investigated over the years traced back to the same place: the code, not the platform. SQL built by string concatenation. User input flowing straight into a query or the DOM. Business logic living in the middle of a 400-line tag page. A cache that was added to hide a slow query, then became the architecture.
ColdFusion programming — done well — is the discipline that keeps those failure modes out of the codebase. It's about how you structure components, how you bind parameters, where you validate, how you handle error, and how much of the system a new developer can understand in an afternoon instead of a month.
This page is a working description of how we write CFML: the architecture patterns, the query habits, the error-handling posture, and the small decisions that compound into a system you can trust for years.
Architecture
Component-first, always
The single biggest quality divider in ColdFusion code is this: is the logic in components, or in the markup? A tag page that runs a query, branches on the result, formats the output, and sends the email is doing four jobs in one place. When the fourth one breaks, you're debugging the first three.
Our pattern is consistent: thin pages, thick components. A page renders; a CFC decides. Each CFC owns one concern — orders, customers, notifications, reports — and exposes a small, named set of functions. That gives you three things for free:
- Testability. A component's function can be exercised without a browser.
- Reuse. The same order logic serves the web form, the API, and the nightly report.
- Onboarding speed. A new developer navigates by intent ("find the orders component"), not by line number.
The shape of a clean CFML codebase
- Pages: presentation only — render, don't decide
- Components: one concern each, small public surface
- Data access: isolated, parameterized, commented where non-obvious
- Utilities: validation and formatting in shared, named helpers
- Config: environment-driven, no secrets in source
- Errors: centralized, safe outward, detailed inward
Query Discipline
Queries written to be trusted
The habits that keep data access safe and fast as the system grows.
Bind every value
cfqueryparam or ORM binding on every input — no exception. Concatenation is how SQL injection gets in, and it's how slow, uncacheable queries get in too.
Select what you need
Narrow columns, explicit WHERE clauses, and an eye on the plan. A query that returns ten thousand rows to find one answer is a design problem, not a database problem.
Cache deliberately
Caching is a strategy, not a reflex. We cache what's expensive and stable, and we never let a cache hide a query that should have been fixed.
Isolate the data layer
Data access lives in one place per concern, so a schema change touches functions — not twenty scattered tag pages.
Measure before and after
Every performance change ships with a number: before, after, and the conditions under which it was measured.
The Edges
Validation, encoding, and error handling
The unglamorous parts are where security lives. Our posture is consistent:
- Validate at the edge. Every external input — form, URL, header, file — is checked against an explicit rule before it's trusted. Not "probably fine," but a named rule: type, length, pattern, range.
- Encode at the exit. Output is encoded for its context — HTML, attribute, JS, URL. This is what makes stored XSS a non-event.
- Fail safe, log loud. Errors are caught centrally. Users see a calm, generic message. The log gets the full picture — type, message, location, request context — so the fix is fast.
- Never leak internals. Stack traces, driver errors, and server paths stay on the server. In production, the user sees a safe page, full stop.
Why this matters in practice
These aren't academic. A missing validation rule is a data-integrity bug waiting for one unusual input. An unencoded output is a stored-XSS vector. A raw error page is an information disclosure. Each one is small to prevent and expensive to discover later.
Doing them by default — on every build, every change — is what "senior" means in practice.
Tag vs. Script
Two dialects, one rule
ColdFusion has two syntaxes — tag-based and script-based — and both are first-class. The mistake isn't choosing one over the other; it's mixing them inside a single code block, which is a compile error, and drifting between them file to file until nobody knows the house style.
Our convention is deliberate and consistent: tag-based for template and page code, where it reads naturally; script-based inside CFCs, where structure, conditionals, and loops want the tighter syntax. And within any file, one dialect — so the codebase reads like one author wrote it, because the rules leave no room for drift.
The reason this matters beyond aesthetics: a consistent dialect makes review faster, onboarding faster, and refactoring safer. Style is a maintenance feature.
House rules we hold
- One dialect per file — no mid-file switching
- No tags inside script blocks, ever
- Named, single-purpose components
- Explicit > implicit — no magic, no guesswork
- Comments explain why, not what
- If a new dev needs a tour, the code isn't done
Related
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FAQ
ColdFusion programming, answered
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