ignition-expressions

Ignition Expression Language Reference

Ignition expressions are used in tag expression bindings and Perspective property bindings. They are NOT Python — they use a distinct function-based syntax.

Syntax

if({[.]value} > 100, "High", "Normal")
dateFormat(now(5000), "HH:mm:ss")
tag("[default]Path/To/Tag")
runScript("project.library.myFunc", 5000, arg1)

Property references: {this.props.value}, {view.custom.myProp}, {view.params.x}, {[.]tagProperty}

Functions (104 total)

Math (12)

• abs(value) — Absolute value
• ceil(value) — Round up
• floor(value) — Round down
• log(value) — Natural logarithm
• max(a, b) — Greater of two values
• min(a, b) — Lesser of two values
• mod(dividend, divisor) — Remainder
• pow(base, exponent) — Exponentiation
• rand() — Random double 0.0-1.0
• round(value) — Round to nearest integer
• signum(value) — Sign (-1, 0, 1)
• sqrt(value) — Square root

String (24)

• concat(str1, str2, ...) — Concatenate strings
• endsWith(string, suffix) — Suffix check
• indexOf(string, substring) — First occurrence index (-1 if not found)
• left(string, count) — Leftmost characters
• len(string) — String length
• lower(string) — To lowercase
• ltrim(string) — Remove leading whitespace
• mid(string, start, length) — Substring by position and length
• numberFormat(value, format) — Format number (Java DecimalFormat)
• regexExtract(string, pattern) — Extract regex match
• repeat(string, count) — Repeat string
• replace(string, search, replacement) — Replace all occurrences
• reverse(string) — Reverse characters
• right(string, count) — Rightmost characters
• rtrim(string) — Remove trailing whitespace
• split(string, delimiter) — Split into array
• startsWith(string, prefix) — Prefix check
• substring(string, start, end) — Substring by indices
• toStr(value) — Convert to string
• trim(string) — Remove surrounding whitespace
• unicodeNormalize(string, form) — Unicode normalization (NFC, NFD, NFKC, NFKD)
• upper(string) — To uppercase
• urlDecode(string) — URL decode
• urlEncode(string) — URL encode

Date/Time (16)

• dateArith(date, field, amount) — Add/subtract from date field ("hour", "day", "month")
• dateDiff(date1, date2, field) — Difference in field units
• dateExtract(date, field) — Extract field ("year", "month", "day", "hour")
• dateFormat(date, format) — Format date (Java SimpleDateFormat)
• dateParse(string, format) — Parse string to date
• daysBetween(date1, date2) — Days between dates
• hoursBetween(date1, date2) — Hours between dates
• millisBetween(date1, date2) — Millis between dates
• minutesBetween(date1, date2) — Minutes between dates
• monthsBetween(date1, date2) — Months between dates
• now(pollRate) — Current date/time. Always specify rate: now(5000) or now(0)
• secondsBetween(date1, date2) — Seconds between dates
• setTime(date, hour, minute, second) — Set time components
• toDate(value) — Convert to date (epoch millis or string)
• weeksBetween(date1, date2) — Weeks between dates
• yearsBetween(date1, date2) — Years between dates

Logic (8)

• choose(index, value0, value1, ...) — Select by 0-based index
• coalesce(value1, value2, ...) — First non-null value
• hasChanged(value) — True if value changed since last evaluation
• if(condition, trueValue, falseValue) — Conditional
• isNull(value) — Null check
• previousValue(value) — Previous evaluation's value
• qualify(tagPath) — Qualify tag path with current provider
• switch(value, case1, result1, ..., default) — Case matching

Type Casting (7)

toBool, toColor(r,g,b), toDataSet, toDouble, toFloat, toInt, toLong

Dataset (10)

• avg(values...) — Average
• columnCount(dataset) — Column count
• dataSetToJSON(dataset) — Dataset to JSON string
• forEach(dataset, expression) — Evaluate per row
• getColumn(dataset, columnIndex) — Column as array
• hasRows(dataset) — Has at least one row
• jsonToDataSet(json) — JSON to dataset
• lookup(dataset, lookupCol, lookupVal, resultCol) — Column lookup
• rowCount(dataset) — Row count
• sum(values...) — Sum

JSON (8)

• jsonDecode(json) — Parse JSON
• jsonDelete(json, path) — Remove at path
• jsonEncode(value) — Serialize to JSON
• jsonKeys(json) — Object keys
• jsonLength(json) — Array/object length
• jsonMerge(json1, json2) — Deep merge (json2 wins)
• jsonSet(json, path, value) — Set at path
• jsonValueByKey(json, key) — Get by key

Tag Quality (7)

• hasQuality(value, quality) — Check quality code
• isBad(value) — Bad quality
• isGood(value) — Good quality
• isNotGood(value) — Not good quality
• isUncertain(value) — Uncertain quality
• tag(tagPath) — Read tag value
• tagCount(folderPath) — Count tags in folder

Color (2)

• chooseColor(index, color0, color1, ...) — Select color by index
• colorMix(color1, color2, bias) — Blend colors (0.0=color1, 1.0=color2)

Advanced (10)

• binDecode(string, encoding) — Decode binary (Base64, Hex)
• binEncode(data, encoding) — Encode binary
• forceQuality(value, qualityCode) — Set quality code
• getMillis() — Current epoch millis
• htmlToPlain(html) — Strip HTML tags
• isAuthorized(requiredRoles...) — Security role check
• mapLat(value) — Latitude from map coordinate
• mapLng(value) — Longitude from map coordinate
• runScript(scriptPath, pollRate, args...) — Call project script
• typeOf(value) — Type name string

Key Tips

• now() defaults to 1000ms polling — always use now(5000) or now(0)
• runScript("project.library.func", 5000, arg1) calls project scripts from expressions
• Avoid getSibling(), getParent(), getChild(), getComponent() — break on restructure
• Property refs: {this.props.X} (own), {view.custom.X} (view), {view.params.X} (params)