Class: BarefootJS::Context

Inherits:
Object
  • Object
show all
Defined in:
lib/barefoot_js.rb

Overview

Context is the bf object every compiled .erb template receives as a local. One instance per render (root or child); render_child / register_components_from_manifest construct a fresh child instance per nested render, chaining scope/slot identity off the caller.

Constant Summary collapse

NUMERIC_STRING_RE =

JS-compat callees -- invoked from generated ERB templates as bf.json(val), bf.floor(val), etc. Numeric coercion follows JS semantics (NaN propagates; non-numeric input yields NaN rather than silently 0). json bubbles backend/marshalling errors loudly rather than producing an empty payload.

/\A\s*[+-]?(?:\d+\.?\d*|\.\d+)(?:[eE][+-]?\d+)?\s*\z/.freeze
FORMAT_DATE_OFFSET_RE =

tz shapes FORMAT_DATE_OFFSET_RE matches: a fixed UTC offset ±HH:MM within ECMA-402's valid range -- hours 00-23, minutes 00-59 ('+09:00', '-05:30') -- one of the three tz shapes format_date accepts (mirrors OFFSET_RE in packages/client/src/format-date.ts). An out-of-range shape ('+25:00') falls through to the tzdata lookup, fails it, and raises -- matching the JS reference's RangeError (#2344).

/\A([+-])([01]\d|2[0-3]):([0-5]\d)\z/
FORMAT_DATE_TOKEN_RE =

Longest-match pattern-token alternation (mirrors TOKEN_RE in packages/client/src/format-date.ts). Order matters: Onigmo, like JS's regex engine, resolves alternation leftmost-first (not POSIX leftmost-longest), so every multi-char token must be listed before any shorter alternative it prefixes -- YYYY before (nothing shorter shares its prefix), MMMM before MMM before MM before M, DD before D, dddd before ddd. (#2334)

/YYYY|MMMM|MMM|MM|DD|dddd|ddd|M|D/
FORMAT_DATE_MONTHS_WIDE =

names-table section offsets (spec/template-helpers.md "format_date", #2334) -- mirrors MONTHS_WIDE/MONTHS_ABBR/WEEKDAYS_WIDE/WEEKDAYS_ABBR in packages/client/src/format-date.ts.

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FORMAT_DATE_MONTHS_ABBR = 
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FORMAT_DATE_WEEKDAYS_WIDE = 
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FORMAT_DATE_WEEKDAYS_ABBR = 
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Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(backend = nil) ⇒ Context

Returns a new instance of Context.



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# File 'lib/barefoot_js.rb', line 81

def initialize(backend = nil)
  @backend = backend
end

Class Method Details

.derive_vars_from_defaults(defaults, props) ⇒ Object

Derive template-var kvs from a manifest entry's ssrDefaults section. Each entry shape: { value:, propName:, isRestProps: }. For isRestProps, the rest bag passes through unchanged (or the static {} if the caller didn't supply one). For ordinary entries the caller's props[propName] wins when present, otherwise the static value does. propName-less entries (signal / memo locals) always use the static value.

Public (not private_class_method): register_components_from_manifest above uses it for the ui/* registry path, but a page that composes flat (non-ui/*) components by hand -- e.g. the blog islands in the Sinatra/xslate/Mojolicious integrations -- needs the exact same ssrDefaults-seeding logic for its own manual register_child_renderer calls. Mirrors the Perl runtime's BarefootJS::_derive_stash_from_defaults, which is likewise callable from integration code (Perl has no enforced privacy; the leading underscore is convention only) -- see integrations/xslate/app.psgi's _register_blog_child and integrations/mojolicious/app.pl's equivalent.



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# File 'lib/barefoot_js.rb', line 362

def self.derive_vars_from_defaults(defaults, props)
  extra = {}
  defaults.each do |name, d|
    unless d.is_a?(Hash)
      extra[name] = d
      next
    end
    if d[:isRestProps]
      extra[name] = props.key?(name) ? props[name] : d[:value]
      next
    end
    # `propName` rides in from the JSON manifest as a String -- JSON has
    # no symbol type, and the manifest's `symbolize_names: true` parse
    # only symbolizes hash KEYS, never string values. Runtime prop
    # hashes, meanwhile, are symbol-keyed because compiled ERB templates
    # pass `{ children: ... }` literals, so `props.key?(prop_name)` with
    # the String would always miss, silently falling back to the static
    # default for every manifest-registered child (e.g. `children`
    # rendering empty) (#2157).
    prop_name = d[:propName]&.to_sym
    extra[name] =
      if !prop_name.nil? && props.key?(prop_name) && !props[prop_name].nil?
        props[prop_name]
      else
        d[:value]
      end
  end
  extra
end

Instance Method Details

#abs(value) ⇒ Object

Math.abs() (#2168 math-methods).



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# File 'lib/barefoot_js.rb', line 513

def abs(value)
  n = number(value)
  nan_number?(n) ? n : n.abs
end

#async_boundary(id, fallback_html) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 400

def async_boundary(id, fallback_html)
  fallback_html = backend.materialize(fallback_html)
  %(<div bf-async="#{id}">#{fallback_html}</div>)
end

#async_resolve(id, content_html) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 405

def async_resolve(id, content_html)
  %(<template bf-async-resolve="#{id}">#{content_html}</template><script>__bf_swap("#{id}")</script>)
end

#at(recv, i) ⇒ Object

Array.prototype.at(i) -- negative indices count from the end; out-of-bounds -> nil (renders as '' via h, matching JS undefined).



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# File 'lib/barefoot_js.rb', line 935

def at(recv, i)
  return nil unless recv.is_a?(Array)
  return nil if i.nil?

  idx = i.to_i
  len = recv.length
  return nil if len.zero?

  idx = len + idx if idx.negative?
  return nil if idx.negative? || idx >= len

  recv[idx]
end

#bool_str(value) ⇒ Object

Map a JS-boolean-shaped value to the JS String(bool) form. See BarefootJS.pm's bool_str docstring for the boolean-only contract -- callers must have already classified the expression as boolean- result; non-boolean attribute bindings never reach this helper.



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# File 'lib/barefoot_js.rb', line 179

def bool_str(value)
  value ? 'true' : 'false'
end

#ceil(value) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 480

def ceil(value)
  n = number(value)
  finite_number?(n) ? n.ceil : n
end

#comment(text) ⇒ Object

Comment Markers



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# File 'lib/barefoot_js.rb', line 171

def comment(text)
  "<!--bf-#{text}-->"
end

#concat(a, b) ⇒ Object

Array.prototype.concat(other) -- merges two arrays in order into a new Array. Non-array operands collapse to empty.



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# File 'lib/barefoot_js.rb', line 951

def concat(a, b)
  out = []
  out.concat(a) if a.is_a?(Array)
  out.concat(b) if b.is_a?(Array)
  out
end

#data_key_attr ⇒ Object

Emits data-key="<key>" for a keyed loop item, else ''. See BarefootJS.pm's docstring on the client reconciliation contract.



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# File 'lib/barefoot_js.rb', line 116

def data_key_attr
  k = _data_key
  return '' if k.nil?

  escaped = k.to_s.gsub('&', '&amp;').gsub('"', '&quot;')
  %( data-key="#{escaped}")
end

#date(recv, op) ⇒ Object

date(recv, op) -- zero-arg Date.prototype method lowering (#2274, spec entry "date"). recv arrives as either this runtime's own Time or an ISO-8601 String (a template prop may carry either depending on how the host populated it), so both normalize through Time.iso8601 / #utc to the same instant before dispatch. #mon is 1-based in Ruby; only getUTCMonth subtracts 1 to match JS's 0-based month. getTime sums whole milliseconds from tv_sec/tv_nsec rather than rounding a Float ms value -- tv_nsec is always the non-negative sub-second remainder (Ruby normalizes Time's internal rational), even for a pre-epoch instant, so integer division here stays exact.



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# File 'lib/barefoot_js.rb', line 528

def date(recv, op)
  # A nil or unparseable receiver degrades to the zero value the
  # Go / Rust / Perl helpers document (empty string for toISOString,
  # 0 otherwise), rather than raising mid-render.
  t =
    if recv.is_a?(Time)
      recv
    else
      begin
        Time.iso8601(recv.to_s)
      rescue ArgumentError
        nil
      end
    end
  return (op == 'toISOString' ? '' : 0) if t.nil?
  t = t.utc
  case op
  when 'getUTCFullYear' then t.year
  when 'getUTCMonth' then t.mon - 1
  when 'getUTCDate' then t.day
  when 'getUTCHours' then t.hour
  when 'getUTCMinutes' then t.min
  when 'getUTCSeconds' then t.sec
  when 'getTime' then (t.tv_sec * 1000) + (t.tv_nsec / 1_000_000)
  when 'toISOString' then t.strftime('%Y-%m-%dT%H:%M:%S.%LZ')
  else 0
  end
end

#ends_with(recv, suffix, end_position = nil) ⇒ Object

String.prototype.endsWith(suffix, endPosition?).



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# File 'lib/barefoot_js.rb', line 1135

def ends_with(recv, suffix, end_position = nil)
  s = recv.nil? ? '' : string(recv)
  x = suffix.nil? ? '' : string(suffix)
  unless end_position.nil?
    e = clamp_index(end_position.to_i, s.length)
    s = s[0...e]
  end
  s.end_with?(x)
end

#every(recv, pred) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 730

def every(recv, pred)
  return true unless recv.is_a?(Array)

  recv.all? { |item| pred.call(item) }
end

#every_eval(recv, pred_json, param, base_env = {}) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1340

def every_eval(recv, pred_json, param, base_env = {})
  Evaluator.every_json(recv, pred_json, param, base_env)
end

#filter(recv, pred) ⇒ Object

.filter(fn) / .every(fn) / .some(fn) / .find(fn) / .findIndex(fn) / .findLast(fn) / .findLastIndex(fn) -- legacy block-predicate path for shapes the compiler lowers to a native callable (e.g. a Kolon-style lambda literal). pred is anything responding to #call(item). The _eval family below is the evaluator-driven generalisation used for arbitrary pure bodies.



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# File 'lib/barefoot_js.rb', line 724

def filter(recv, pred)
  return [] unless recv.is_a?(Array)

  recv.select { |item| pred.call(item) }
end

#filter_eval(recv, pred_json, param, base_env = {}) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1336

def filter_eval(recv, pred_json, param, base_env = {})
  Evaluator.filter_json(recv, pred_json, param, base_env)
end

#find(recv, pred) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 742

def find(recv, pred)
  return nil unless recv.is_a?(Array)

  recv.find { |item| pred.call(item) }
end

#find_eval(recv, pred_json, param, forward = true, base_env = {}) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1348

def find_eval(recv, pred_json, param, forward = true, base_env = {})
  Evaluator.find_json(recv, pred_json, param, forward, base_env)
end

#find_index(recv, pred) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 748

def find_index(recv, pred)
  return -1 unless recv.is_a?(Array)

  recv.each_index { |i| return i if pred.call(recv[i]) }
  -1
end

#find_index_eval(recv, pred_json, param, forward = true, base_env = {}) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1352

def find_index_eval(recv, pred_json, param, forward = true, base_env = {})
  Evaluator.find_index_json(recv, pred_json, param, forward, base_env)
end

#find_last(recv, pred) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 755

def find_last(recv, pred)
  return nil unless recv.is_a?(Array)

  recv.reverse_each { |item| return item if pred.call(item) }
  nil
end

#find_last_index(recv, pred) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 762

def find_last_index(recv, pred)
  return -1 unless recv.is_a?(Array)

  (recv.length - 1).downto(0) { |i| return i if pred.call(recv[i]) }
  -1
end

#flat(recv, depth = 1) ⇒ Object

Array.prototype.flat(depth?) -- flatten nested arrays depth levels deep. depth of -1 is the Infinity sentinel (flatten fully); 0 returns a shallow copy.



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# File 'lib/barefoot_js.rb', line 1000

def flat(recv, depth = 1)
  return [] unless recv.is_a?(Array)

  out = []
  recv.each do |el|
    if !depth.zero? && el.is_a?(Array)
      out.concat(flat(el, depth.positive? ? depth - 1 : depth))
    else
      out << el
    end
  end
  out
end

#flat_dynamic(recv, depth) ⇒ Object

Array.prototype.flat(depth) where depth is a DYNAMIC value (#2094) -- e.g. items.flat(props.depth) -- rather than a compile-time literal. Coerces depth via JS ToIntegerOrInfinity (truncate toward zero; NaN/non-numeric -> 0; negative -> 0; +Infinity or a huge finite value -> flatten fully) and delegates to flat.

This is a SEPARATE method from flat, not a smarter overload of it: flat's depth parameter treats -1 as a compile-time SENTINEL meaning "the source literally wrote Infinity" (the parser's own normalisation, baked into the emitted template). A genuinely dynamic depth value that happens to be -1 at render time means the JS-correct OPPOSITE: .flat(-1) never recurses (same as .flat(0), a shallow copy), because real JS only recurses when depth > 0. Reusing flat's int contract for a raw dynamic value would silently invert that case, so this coerces FIRST -- mapping a real +Infinity / huge finite value to flat's own -1 sentinel, and a real negative value to 0 -- and only then delegates to flat's recursion. Mirrors Go's FlatDynamicDepth/coerceFlatDepth (adapter-go-template/runtime/bf.go).



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# File 'lib/barefoot_js.rb', line 1032

def flat_dynamic(recv, depth)
  flat(recv, coerce_flat_depth(depth))
end

#flat_map(recv, key_kind, key) ⇒ Object

Array.prototype.flatMap(fn) value-returning field projection: map each element through a self/field projection, then flatten one level.



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# File 'lib/barefoot_js.rb', line 1038

def flat_map(recv, key_kind, key)
  return [] unless recv.is_a?(Array)

  projected = recv.map { |el| key_kind == 'field' ? field_value(el, key) : el }
  flat(projected, 1)
end

#flat_map_eval(recv, proj_json, param, base_env = {}) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1356

def flat_map_eval(recv, proj_json, param, base_env = {})
  Evaluator.flat_map_json(recv, proj_json, param, base_env)
end

#flat_map_tuple(recv, *specs) ⇒ Object

Array.prototype.flatMap(i => [i.a, i.b]) -- array-literal tuple projection. Each spec is [kind, key] (['self', ''] or ['field', 'a']).



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# File 'lib/barefoot_js.rb', line 1048

def flat_map_tuple(recv, *specs)
  return [] unless recv.is_a?(Array)

  out = []
  recv.each do |el|
    specs.each do |kind, key|
      out << (kind == 'field' ? field_value(el, key) : el)
    end
  end
  out
end

#floor(value) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 475

def floor(value)
  n = number(value)
  finite_number?(n) ? n.floor : n
end

#format_date(recv, pattern, tz, names = []) ⇒ Object

format_date(recv, pattern, tz, names) (#2324/#2334, spec entry "format_date" in spec/template-helpers.md) -- the lowering target for formatDate(date, pattern, timeZone, names) (packages/client/src/format-date.ts, the JS-normative reference this must match byte-for-byte). Total and deterministic: no locale, no host timezone, no Time.now.

recv: the same receiver contract as date above -- a native Time or an ISO-8601 string, normalized identically. A nil / unparseable receiver renders '' (never raises mid-render).

tz (#2344): 'UTC', a range-valid fixed offset ±HH:MM (shifts the instant by sign*(HH*60+MM) minutes), or a canonical IANA zone name ('Asia/Tokyo') resolved through tzdata via the tzinfo gem -- the zone's UTC offset AT THE INSTANT being formatted (DST-aware, historical-transition-aware, seconds precision: pre-standard LMT offsets like Tokyo's +09:18:59 count). ANY other value -- an unknown zone, a non-canonical spelling, a malformed or out-of-range offset ('+9:00', '+25:00') -- raises ArgumentError, aborting the render loudly: the JS reference throws a RangeError there, and a silently substituted timezone is the one failure mode this helper must not have (the pre-#2344 normalize-to-UTC total function is gone). The shifted instant's UTC calendar fields (not the original instant's) are what pattern tokens read -- the shifted UTC clock face IS the local clock face in that zone. Time arithmetic here is exact (Ruby represents the instant as a Rational, not a floor-divided epoch-millis integer), so there's no pre-1970 negative-epoch floor-division trap to dodge the way a naive epoch-millis-div-86400000 implementation would hit; the shifted Time#wday (0 = Sunday) is likewise exact across the epoch boundary, so it doubles directly as the weekday-name table index.

names: the flat table (#2334) -- [0..11] wide months, [12..23] abbreviated months, [24..30] wide weekdays (Sunday-first, matching the shifted Time#wday), [31..37] abbreviated weekdays. The caller owns the values (locale selection is never this method's job). An index past a missing/short table renders '' rather than raising.

pattern: longest-match token substitution (YYYY|MMMM|MMM|MM|DD|dddd|ddd|M|D); every other character -- including multi-byte ones like 年/月/日 -- passes through literally. YYYY is abs(year) zero-padded to 4 digits, --prefixed for a negative year; MM/DD zero-pad to 2; M/D are bare; MMMM/MMM read the month's wide/abbreviated name; dddd/ddd read the shifted weekday's wide/abbreviated name.



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# File 'lib/barefoot_js.rb', line 627

def format_date(recv, pattern, tz, names = [])
  t =
    if recv.is_a?(Time)
      recv
    else
      begin
        Time.iso8601(recv.to_s)
      rescue ArgumentError
        nil
      end
    end
  return '' if t.nil?

  tz_s = tz.to_s
  offset_seconds = 0
  if tz_s != 'UTC'
    m = FORMAT_DATE_OFFSET_RE.match(tz_s)
    offset_seconds =
      if m
        (m[1] == '-' ? -1 : 1) * ((m[2].to_i * 60) + m[3].to_i) * 60
      else
        format_date_zone_offset(tz_s, t)
      end
  end

  shifted = (t.utc + offset_seconds).utc
  year = shifted.year
  month = shifted.mon
  day = shifted.mday
  weekday = shifted.wday # 0 = Sunday, matching the table's Sunday-first layout
  yyyy = (year.negative? ? '-' : '') + year.abs.to_s.rjust(4, '0')
  name_at = ->(index) { (names[index] || '').to_s }

  pattern.gsub(FORMAT_DATE_TOKEN_RE) do |token|
    case token
    when 'YYYY' then yyyy
    when 'MMMM' then name_at.call(FORMAT_DATE_MONTHS_WIDE + month - 1)
    when 'MMM' then name_at.call(FORMAT_DATE_MONTHS_ABBR + month - 1)
    when 'MM' then format('%02d', month)
    when 'M' then month.to_s
    when 'DD' then format('%02d', day)
    when 'D' then day.to_s
    when 'dddd' then name_at.call(FORMAT_DATE_WEEKDAYS_WIDE + weekday)
    when 'ddd' then name_at.call(FORMAT_DATE_WEEKDAYS_ABBR + weekday)
    end
  end
end

#format_date_zone_offset(tz, t) ⇒ Object

Resolve a canonical IANA zone ID's UTC offset (whole seconds) at instant t through the tzinfo gem (#2344) -- TZInfo resolves the exact-case canonical ID set every backend shares, with full historical transitions (LMT seconds included). The gem is required lazily so the fixed-offset/'UTC' paths -- and every other helper -- keep working on a gem-less stdlib install; reaching a named zone without the gem raises the same loud ArgumentError as an unknown zone (never a silent UTC fallback).



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# File 'lib/barefoot_js.rb', line 683

def format_date_zone_offset(tz, t)
  begin
    require 'tzinfo'
  rescue LoadError
    raise ArgumentError,
          "format_date: IANA timeZone #{tz.inspect} requires the tzinfo gem (~> 2.0)"
  end
  begin
    zone = TZInfo::Timezone.get(tz)
  rescue TZInfo::InvalidTimezoneIdentifier
    raise ArgumentError, "format_date: unresolvable timeZone #{tz.inspect}"
  end
  zone.period_for_utc(t.utc).observed_utc_offset
end

#get(collection, key) ⇒ Object

Runtime-polymorphic element/key access for arr[index] / hash[key] (emitIndexAccessRuby, expr/operand.ts). Row hashes deserialize with symbolize_names: true, so a dynamic key whose runtime value is a String (e.g. a destructured .map() param used as a key, tone[k]) misses a Symbol-keyed Hash outright -- and the shared analyzer can't tell at compile time whether an index will turn out to be a string key or a numeric index (it types a destructured param {kind:'unknown'}), so no compile-time branch can pick the right access form (#2491). Mirrors getFieldValue's (Go adapter, bf.go) case-tolerant lookup and Twig's attribute(): for a Hash, try the key as-is, then as a Symbol, then as a String; for an Array, index numerically; anything else has no lookup to perform.



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# File 'lib/barefoot_js.rb', line 813

def get(collection, key)
  return nil if key.nil?

  case collection
  when Hash
    return collection[key] if collection.key?(key)

    sym = key.respond_to?(:to_sym) ? key.to_sym : nil
    return collection[sym] if sym && collection.key?(sym)

    str = key.to_s
    return collection[str] if collection.key?(str)

    nil
  when Array
    # Only an INTEGRAL index reads an element. `key.to_i` would be
    # wrong on both ends: it coerces a non-numeric String to 0
    # (`arr["nope"]` must be nil, not the first element) and it
    # truncates a fractional number (JS `arr[1.2]` is a property
    # lookup, i.e. undefined -- not index 1).
    idx =
      case key
      when Integer then key
      when Numeric then (key % 1).zero? ? key.to_i : nil
      when String then (key =~ /\A-?\d+\z/ ? key.to_i : nil)
      end
    return nil if idx.nil?

    # JS-semantics negative index is "not found" (`arr[-1] ===
    # undefined`), NOT Ruby's native from-the-end wraparound -- guard
    # it explicitly so this stays a superset of bracket access rather
    # than a divergent one.
    return nil if idx.negative?

    collection[idx]
  end
end

#h(value) ⇒ Object

HTML-escaping helper for text interpolation (<%= bf.h(expr) %> -- stdlib ERB does not auto-escape). JS-style stringification via string (numbers per JS Number#toString, nil -> "", booleans -> "true"/"false"), then HTML-escaped. A SafeString (already-finished HTML forwarded from a parent's capture -- see that class's docstring) passes through unescaped, matching Twig/Blade/Kolon's safe-string bypass on their own auto-escaping {{ }}/<: :> output tags.



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# File 'lib/barefoot_js.rb', line 450

def h(value)
  return value if value.is_a?(SafeString)

  html_escape(string(value))
end

#has_unsafe_style_value?(value) ⇒ Boolean

Mirrors Hono's own CSS-injection guard (hono/jsx/utils.ts's hasUnsafeStyleValue -- the ORACLE a dynamic style={{...}} value must match, #2261): a hand-rolled structural scan for characters that could break out of a CSS declaration, NOT real CSSOM property validation. Ported byte-for-byte -- every character this scan tests is ASCII, so scanning by byte agrees with Hono's UTF-16-code-unit scan for every input; a multibyte UTF-8 sequence has no byte in the ASCII range, so it can never spuriously match one of these single-byte comparisons. Skips the reference implementation's regex fast-path (a pure optimization -- the scan below already returns false promptly for a clean value).

Returns:

  • (Boolean) 


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# File 'lib/barefoot_js.rb', line 862

def has_unsafe_style_value?(value)
  bytes = value.b
  quote = 0
  block_stack = []
  i = 0
  len = bytes.bytesize
  while i < len
    c = bytes.getbyte(i)
    if c == 92 # \
      return true if i == len - 1
      i += 1
    elsif quote != 0
      return true if c == 10 || c == 12 || c == 13
      quote = 0 if c == quote
    elsif c == 47 && i + 1 < len && bytes.getbyte(i + 1) == 42 # "/*"
      endi = bytes.index('*/', i + 2)
      return true if endi.nil?
      i = endi + 1
    elsif c == 34 || c == 39 # " or '
      quote = c
    elsif c == 40 # (
      block_stack.push(41)
    elsif c == 91 # [
      block_stack.push(93)
    elsif c == 123 || c == 125 # { or }
      return true
    elsif c == 41 || c == 93 # ) or ]
      return true if block_stack.empty? || block_stack.last != c
      block_stack.pop
    elsif c == 59 && block_stack.empty? # ;
      return true
    end
    i += 1
  end
  quote != 0 || !block_stack.empty?
end

#hydration_attrs ⇒ Object

Emits bf-h="<host>" bf-m="<slot>" bf-r="" conditionally. See spec/compiler.md "Slot identity".



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# File 'lib/barefoot_js.rb', line 104

def hydration_attrs
  parts = []
  host = _bf_parent
  mount = _bf_mount
  parts << %(bf-h="#{host.gsub('"', '&quot;')}") if host && !host.empty?
  parts << %(bf-m="#{mount.gsub('"', '&quot;')}") if mount && !mount.empty?
  parts << 'bf-r=""' unless _is_child
  parts.join(' ')
end

#includes(recv, elem) ⇒ Object

Array.prototype.includes(x) / String.prototype.includes(sub) share a method name in JS; dispatch on Ruby class the way BarefootJS.pm dispatches on ref(). The Array arm scans with Evaluator.same_value_zero? (SameValueZero: no cross-type coercion, e.g. [2].includes("2") is false; NaN matches NaN) -- the same algorithm the evaluator's serialized-callback array-method path uses for .includes, so both positions agree.



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# File 'lib/barefoot_js.rb', line 709

def includes(recv, elem)
  return recv.any? { |item| Evaluator.same_value_zero?(item, elem) } if recv.is_a?(Array)
  return false if recv.is_a?(Hash)

  s = recv.nil? ? '' : string(recv)
  needle = elem.nil? ? '' : string(elem)
  s.include?(needle)
end

#index_of(recv, elem) ⇒ Object

Array.prototype.indexOf(x) / .lastIndexOf(x) -- value-equality search. Non-array receivers return -1.



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# File 'lib/barefoot_js.rb', line 925

def index_of(recv, elem)
  array_index_of(recv, elem, false)
end

#join(recv, sep = nil) ⇒ Object

Array.prototype.join(sep) with JS semantics: separator defaults to ",", undefined/null elements render as empty.



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# File 'lib/barefoot_js.rb', line 780

def join(recv, sep = nil)
  return '' unless recv.is_a?(Array)

  sep = ',' if sep.nil?
  recv.map { |el| string(el) }.join(sep)
end

#json(value) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 419

def json(value)
  backend.encode_json(value)
end

#last_index_of(recv, elem) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 929

def last_index_of(recv, elem)
  array_index_of(recv, elem, true)
end

#lc(s) ⇒ Object

String.prototype.toLowerCase() / .toUpperCase().



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# File 'lib/barefoot_js.rb', line 770

def lc(s)
  s.nil? ? '' : string(s).downcase
end

#length(recv) ⇒ Object

.length works on both arrays (element count) and strings. The string branch counts UTF-16 CODE UNITS, matching JS String.prototype.length (#2255) -- NOT Ruby's native String#length (Unicode codepoints). A codepoint outside the Basic Multilingual Plane (astral, U+10000-U+10FFFF -- e.g. '👍') is a surrogate PAIR in UTF-16, so it counts as 2, not 1; '日本語' is 3 either way (BMP-only).



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# File 'lib/barefoot_js.rb', line 793

def length(recv)
  return recv.length if recv.is_a?(Array)
  return 0 if recv.is_a?(Hash) || recv.nil?

  string(recv).each_char.sum { |c| c.ord > 0xFFFF ? 2 : 1 }
end

#map_eval(recv, proj_json, param, base_env = {}) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1360

def map_eval(recv, proj_json, param, base_env = {})
  Evaluator.map_json(recv, proj_json, param, base_env)
end

#max(a, b) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 503

def max(a, b)
  x = number(a)
  y = number(b)
  return x if nan_number?(x)
  return y if nan_number?(y)

  x > y ? x : y
end

#min(a, b) ⇒ Object

Math.min(a, b) / Math.max(a, b) -- two-arg forms only (#2168 math-methods). JS returns NaN if either operand is NaN. number() may return a plain Integer (no #nan?), so guard like finite_number? above rather than calling #nan? unconditionally.



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# File 'lib/barefoot_js.rb', line 494

def min(a, b)
  x = number(a)
  y = number(b)
  return x if nan_number?(x)
  return y if nan_number?(y)

  x < y ? x : y
end

#number(value) ⇒ Object

JS Number(v) mirror: numeric / boolean inputs convert as expected; non-numeric / nil yield real numeric NaN so downstream arithmetic propagates correctly (Math.floor(NaN) === NaN).



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# File 'lib/barefoot_js.rb', line 466

def number(value)
  return Float::NAN if value.nil?
  return value ? 1 : 0 if value.is_a?(TrueClass) || value.is_a?(FalseClass)
  return value if value.is_a?(Numeric)
  return Float(value.strip) if value.is_a?(String) && value.strip =~ NUMERIC_STRING_RE

  Float::NAN
end

#pad_end(recv, target, pad_str = nil) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1245

def pad_end(recv, target, pad_str = nil)
  pad_string(recv.nil? ? '' : string(recv), target, pad_str, false)
end

#pad_start(recv, target, pad_str = nil) ⇒ Object

String.prototype.padStart / padEnd.



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# File 'lib/barefoot_js.rb', line 1241

def pad_start(recv, target, pad_str = nil)
  pad_string(recv.nil? ? '' : string(recv), target, pad_str, true)
end

#props_attr ⇒ Object 



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# File 'lib/barefoot_js.rb', line 124

def props_attr
  props = _props
  return '' unless props && !props.empty?

  # The JSON must be attribute-escaped: a raw `'` inside a string value
  # (e.g. a blog paragraph) terminates the single-quoted attribute and
  # truncates the hydration payload. The browser entity-decodes the
  # attribute value, so the client's JSON.parse sees the original text.
  json = html_escape(backend.encode_json(props))
  %( bf-p='#{json}')
end

#provide_context(name, value) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 151

def provide_context(name, value)
  CONTEXT_STACKS[name].push(value)
  ''
end

#query(base, *triples) ⇒ Object

queryHref(base, { ... }) (#2042) -- build "base?k=v&..." from a flat list of (guard, key, value) triples. A pair is included iff its guard is truthy AND its value is a non-empty string. A value may instead be an Array, which APPENDS one pair per non-empty member. Repeating a key overwrites the value at its first position (URLSearchParams.set semantics); array members always append (.append semantics).



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# File 'lib/barefoot_js.rb', line 1198

def query(base, *triples)
  b = base.nil? ? '' : string(base)
  pairs = []
  pos = {}
  i = 0
  while i + 2 < triples.length
    guard, key, val = triples[i], triples[i + 1], triples[i + 2]
    i += 3
    next unless truthy?(guard)

    k = key.nil? ? '' : string(key)
    if val.is_a?(Array)
      val.each do |m|
        sm = string(m)
        pairs << [k, sm] unless sm.empty?
      end
      next
    end
    v = val.nil? ? '' : string(val)
    next if v.empty?

    if pos.key?(k)
      pairs[pos[k]][1] = v
    else
      pos[k] = pairs.length
      pairs << [k, v]
    end
  end
  return b if pairs.empty?

  "#{b}?#{pairs.map { |pk, pv| "#{form_escape(pk)}=#{form_escape(pv)}" }.join('&')}"
end

#reduce(recv, opts = {}) ⇒ Object

Fold an array into a scalar via the arithmetic-fold catalogue (legacy, pre-#2018 path; reduce_eval below handles arbitrary reducer bodies). opts: { op: '+'|'*', key_kind:, key:, type: 'numeric'|'string', init:, direction: 'left'|'right' }.



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# File 'lib/barefoot_js.rb', line 1291

def reduce(recv, opts = {})
  op = opts[:op] || '+'
  key_kind = opts[:key_kind] || 'self'
  key = opts[:key] || ''
  type = opts[:type] || 'numeric'
  direction = opts[:direction] || 'left'

  items = recv.is_a?(Array) ? recv.dup : []
  items.reverse! if direction == 'right'
  project = lambda { |item| key_kind == 'field' ? field_value(item, key) : item }

  if type == 'string'
    acc = opts[:init].nil? ? '' : string(opts[:init])
    items.each { |item| acc += string(project.call(item)) }
    return acc
  end

  # `init` rides through the adapter as whatever literal the template
  # emits -- often a numeric-looking String (JSON-decoded, not a Ruby
  # numeric literal) -- so route it through the same numeric coercion
  # as every per-element projection rather than trusting its Ruby class.
  acc = opts[:init].nil? ? 0 : numeric_or_zero(opts[:init])
  items.each do |item|
    n = numeric_or_zero(project.call(item))
    acc = op == '*' ? acc * n : acc + n
  end
  acc
end

#reduce_eval(recv, body_json, acc_name, item_name, init, direction = 'left', base_env = {}) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1332

def reduce_eval(recv, body_json, acc_name, item_name, init, direction = 'left', base_env = {})
  Evaluator.fold_json(recv, body_json, acc_name, item_name, init, direction, base_env)
end

#register_child_renderer(name, renderer) ⇒ Object

Register a renderer for render_child(name, ...). renderer is called as renderer.call(props_hash, invoking_bf) -- the invoking Context matters because a renderer registered on the root may be called from a nested child render, and the grandchild's scope / slot identity must chain off the CALLER's scope id, not the registrant's (#1897).



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# File 'lib/barefoot_js.rb', line 256

def register_child_renderer(name, renderer)
  _child_renderers[name] = renderer
end

#register_components_from_manifest(manifest, signal_init: {}) ⇒ Object

Bulk registration from build manifest

vite build (via @barefootjs/erb/vite's barefoot() plugin) emits dist/templates/manifest.json describing every component the page might invoke. This walks that manifest and registers one child renderer per UI registry entry (ui/<name>/index -> slot key <name>), seeding each child's template vars from the manifest's statically-derived ssrDefaults (prop destructure defaults + signal/memo initial values). signal_init[slot_key] is an opt-in override for defaults the static extractor can't see through.



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# File 'lib/barefoot_js.rb', line 288

def register_components_from_manifest(manifest, signal_init: {})
  parent_scope = _scope_id
  parent = self

  manifest.each do |entry_name, entry|
    next if entry_name.to_s == '__barefoot__'

    m = entry_name.to_s.match(%r{\Aui/([^/]+)/index\z})
    next unless m

    slot_key = m[1]
    marked = entry[:markedTemplate] || ''
    next if marked.empty?

    template_name = marked.sub(%r{\Atemplates/}, '').sub(/\.erb\z/, '')
    sig_init = signal_init[slot_key]
    manifest_defaults = entry[:ssrDefaults]

    register_child_renderer(slot_key, lambda do |props, caller|
      host = caller || parent
      host_scope = host._scope_id || parent_scope
      child_bf = self.class.new(parent.backend)
      slot_id = props.delete(:_bf_slot)
      data_key = props.delete(:key)
      child_bf._data_key(data_key) unless data_key.nil?
      child_bf._scope_id(
        slot_id ? "#{host_scope}_#{slot_id}" : "#{template_name}_#{rand.to_s[2, 6]}",
      )
      child_bf._is_child(true)
      if slot_id
        child_bf._bf_parent(host_scope)
        child_bf._bf_mount(slot_id)
      end
      # Share the root registry so the child's own template can render
      # further imported components (#1897).
      child_bf._child_renderers(parent._child_renderers)
      child_bf._scripts(parent._scripts)
      child_bf._script_seen(parent._script_seen)
      child_bf._preloads(parent._preloads)
      child_bf._preload_seen(parent._preload_seen)

      extra =
        if sig_init
          sig_init.call(props)
        elsif manifest_defaults
          self.class.send(:derive_vars_from_defaults, manifest_defaults, props)
        else
          {}
        end

      html = parent.backend.render_named(template_name, child_bf, props.merge(extra))
      html.chomp
    end)
  end
end

#register_preload(path) ⇒ Object

Register a <link rel="modulepreload"> hint (mirrors register_script exactly: same dedup-by-path set, same insertion-order array, same lifetime/reset semantics, same no-output-string return so the compiled ERB template's <% bf.register_preload(...) %> produces no bytes where it sits). The <link> itself is only ever emitted by scripts below, never here -- a preload registration must never inject a node into a component's own template output (see the previous attempt's regression this guards against).



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# File 'lib/barefoot_js.rb', line 230

def register_preload(path)
  return if _preload_seen.key?(path)

  _preload_seen[path] = true
  _preloads.push(path)
end

#register_script(path) ⇒ Object

Script Registration



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# File 'lib/barefoot_js.rb', line 215

def register_script(path)
  return if _script_seen.key?(path)

  _script_seen[path] = true
  _scripts.push(path)
end

#render_child(name, *args) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 260

def render_child(name, *args)
  renderer = _child_renderers[name]
  raise "No renderer registered for child component '#{name}'" unless renderer

  # Accept both `render_child(name, k: v, ...)` (kwargs collapse into a
  # trailing Hash under Ruby's argument-splat rules) and the explicit
  # single-Hash form `render_child(name, { k: v })`.
  props = (args.length == 1 && args[0].is_a?(Hash)) ? args[0].dup : Hash[*args]
  # JSX children come in via the ERB backend's content-capture buffer
  # slice; materialize it through the backend so the child renderer sees
  # `props[:children]` as already-rendered HTML. Guard on `key?` so a
  # childless invocation doesn't gain a spurious `children: nil` key.
  props[:children] = backend.materialize(props[:children]) if props.key?(:children)
  renderer.call(props, self)
end

#repeat(recv, count) ⇒ Object

String.prototype.repeat(n) -- a count <= 0 degrades to '' rather than raising (JS throws RangeError for negative counts; SSR templates degrade instead of dying mid-render).



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# File 'lib/barefoot_js.rb', line 1234

def repeat(recv, count)
  s = recv.nil? ? '' : string(recv)
  n = count.nil? ? 0 : count.to_i
  n.positive? ? s * n : ''
end

#replace(recv, pattern, replacement) ⇒ Object

String.prototype.replace(pattern, replacement) -- string-pattern form only, replacing the FIRST occurrence, literally (no regex metacharacters, no $1-style replacement interpolation).



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# File 'lib/barefoot_js.rb', line 1148

def replace(recv, pattern, replacement)
  s = recv.nil? ? '' : string(recv)
  o = pattern.nil? ? '' : string(pattern)
  n = replacement.nil? ? '' : string(replacement)
  return n + s if o.empty?

  idx = s.index(o)
  return s if idx.nil?

  s[0...idx] + n + s[(idx + o.length)..]
end

#replace_all(recv, pattern, replacement) ⇒ Object

String.prototype.replaceAll(pattern, replacement) -- string-pattern form only (#2182), replacing EVERY occurrence (the all-occurrences sibling of replace above). Deliberately NOT String#gsub: Ruby's gsub interprets \1 / \& backreference syntax in the replacement even for a literal string pattern ("abc".gsub("b", "\\1") -> "ac", not the literal "\1"), which would diverge from .replace's literal splice above and from the other backends' literal treatment. The index/splice loop keeps the replacement literal, matching replace. An empty pattern inserts at every boundary, including before the first and after the last character ("abc".replaceAll("", "X") -> "XaXbXcX"), matching JS.



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# File 'lib/barefoot_js.rb', line 1171

def replace_all(recv, pattern, replacement)
  s = recv.nil? ? '' : string(recv)
  o = pattern.nil? ? '' : string(pattern)
  n = replacement.nil? ? '' : string(replacement)
  return ([''] + s.chars + ['']).join(n) if o.empty?

  # `+''` (not the frozen `''` literal under frozen_string_literal)
  # so `<<` can append in place instead of `+=` reallocating a new
  # string each iteration (quadratic for long inputs / many matches).
  out = +''
  pos = 0
  loop do
    idx = s.index(o, pos)
    break if idx.nil?

    out << s[pos...idx] << n
    pos = idx + o.length
  end
  out << s[pos..]
end

#reverse(recv) ⇒ Object

Array.prototype.reverse() / .toReversed() -- always returns a new Array (SSR renders a snapshot; the mutate-vs-copy JS distinction is moot here).



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# File 'lib/barefoot_js.rb', line 993

def reverse(recv)
  recv.is_a?(Array) ? recv.reverse : []
end

#revoke_context(name) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 156

def revoke_context(name)
  stack = CONTEXT_STACKS[name]
  stack.pop unless stack.empty?
  ''
end

#round(value) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 485

def round(value)
  n = number(value)
  finite_number?(n) ? (n + 0.5).floor : n
end

#scope_attr ⇒ Object

bf-s is the addressable scope id only (#1249).



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# File 'lib/barefoot_js.rb', line 98

def scope_attr
  _scope_id || ''
end

#scope_comment ⇒ Object

See spec/compiler.md "Slot identity" for the comment-scope wire format.



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# File 'lib/barefoot_js.rb', line 192

def scope_comment
  scope_id = _scope_id || ''
  host_segment = ''
  host = _bf_parent
  mount = _bf_mount
  host_segment = "|h=#{host}|m=#{mount || ''}" if host && !host.empty?
  props_json = ''
  props_json = "|#{backend.encode_json(_props)}" if _props && !_props.empty?
  "<!--bf-scope:#{scope_id}#{host_segment}#{props_json}-->"
end

#scope_comment_end ⇒ Object

Paired end marker for scope_comment, emitted after the fragment's last top-level node. No host/props segments -- the client only needs the scope id to close the boundary (#2289).



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# File 'lib/barefoot_js.rb', line 206

def scope_comment_end
  scope_id = _scope_id || ''
  "<!--bf-/scope:#{scope_id}-->"
end

#scripts ⇒ Object

Emits preload hints BEFORE script tags -- a hint that arrives after the script it describes is useless. Same escaping (none; paths are caller-trusted resolved URLs) as the script tags below.



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# File 'lib/barefoot_js.rb', line 240

def scripts
  preload_tags = _preloads.map { |path| %(<link rel="modulepreload" crossorigin href="#{path}">) }
  script_tags = _scripts.map { |path| %(<script type="module" src="#{path}"></script>) }
  (preload_tags + script_tags).join("\n")
end

#search_params(query = '') ⇒ Object

search_params(query = '') -- request-scoped reader for the reactive searchParams() environment signal (router v0.5, #1922), built from a raw query string. The compiled template reads it via v[:searchParams].get('key').



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# File 'lib/barefoot_js.rb', line 89

def search_params(query = '')
  SearchParams.new(query)
end

#slice(recv, start, end_ = nil) ⇒ Object

Array.prototype.slice(start, end?) AND String.prototype.slice (the string-slice divergence) -- the adapter emits the same bf_slice call for both receiver shapes (it can't disambiguate string vs. array at compile time), so this dispatches on Ruby class, mirroring includes above. Mirrors the Go/Perl bf_slice / slice arithmetic so adapter output stays symmetric. String#length / #[] already index by character (not byte) for a UTF-8-encoded string, matching JS except for astral-plane input (the same divergence boundary every other adapter's pad/trim helpers already accept).



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# File 'lib/barefoot_js.rb', line 968

def slice(recv, start, end_ = nil)
  return [] unless recv.is_a?(Array) || recv.is_a?(String)

  empty = recv.is_a?(String) ? '' : []
  len = recv.length
  return empty if len.zero?

  s = start.nil? ? 0 : start.to_i
  s = len + s if s.negative?
  s = 0 if s.negative?
  s = len if s > len

  e = end_.nil? ? len : end_.to_i
  e = len + e if e.negative?
  e = 0 if e.negative?
  e = len if e > len

  return empty if s >= e

  recv[s...e]
end

#some(recv, pred) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 736

def some(recv, pred)
  return false unless recv.is_a?(Array)

  recv.any? { |item| pred.call(item) }
end

#some_eval(recv, pred_json, param, base_env = {}) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1344

def some_eval(recv, pred_json, param, base_env = {})
  Evaluator.some_json(recv, pred_json, param, base_env)
end

#sort(recv, opts = {}) ⇒ Object

Array.prototype.sort(cmp) / .toSorted(cmp) -- fixed comparator catalogue (legacy, pre-#2018 path; sort_eval below handles arbitrary comparator bodies). opts[:keys] is a priority-ordered list of { key_kind:, key:, compare_type:, direction: }. Stable (ties break on original index) and non-mutating.



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# File 'lib/barefoot_js.rb', line 1254

def sort(recv, opts = {})
  return [] unless recv.is_a?(Array)

  spec = (opts[:keys] || []).map do |k|
    {
      key_kind: k[:key_kind] || 'self',
      key: k[:key] || '',
      compare_type: k[:compare_type] || 'numeric',
      direction: k[:direction] || 'asc',
    }
  end
  return recv.dup if spec.empty?

  decorated = recv.each_with_index.map do |item, idx|
    keys = spec.map { |sp| sp[:key_kind] == 'field' ? field_value(item, sp[:key]) : item }
    [keys, item, idx]
  end

  sorted = decorated.sort do |x, y|
    result = 0
    spec.each_index do |i|
      c = compare_sort_key(x[0][i], y[0][i], spec[i][:compare_type])
      next if c.zero?

      result = spec[i][:direction] == 'desc' ? -c : c
      break
    end
    result.zero? ? (x[2] <=> y[2]) : result
  end

  sorted.map { |pair| pair[1] }
end

#sort_eval(recv, cmp_json, param_a, param_b, base_env = {}) ⇒ Object

Evaluator-driven sort / reduce / higher-order predicates (#2018): the comparator / reducer / predicate body rides as a serialized- ParsedExpr JSON string and is evaluated per element, delegating to the shared BarefootJS::Evaluator. find_eval / find_index_eval take a forward flag (false -> findLast / findLastIndex).



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# File 'lib/barefoot_js.rb', line 1328

def sort_eval(recv, cmp_json, param_a, param_b, base_env = {})
  Evaluator.sort_by_json(recv, cmp_json, param_a, param_b, base_env)
end

#split(recv, sep = nil, limit = nil) ⇒ Object

String.prototype.split(sep) -- string -> Array. An empty separator splits into individual characters; a nil separator returns the whole string in a single-element Array; trailing empty fields are kept (JS parity -- Ruby's String#split(str, -1) already matches this, and (unlike a Regexp) a String separator is matched literally).



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# File 'lib/barefoot_js.rb', line 1100

def split(recv, sep = nil, limit = nil)
  s = (recv.nil? || recv.is_a?(Array) || recv.is_a?(Hash)) ? '' : string(recv)
  parts =
    if sep.nil?
      [s]
    elsif string(sep).empty?
      s.chars
    elsif s.empty?
      ['']
    else
      s.split(string(sep), -1)
    end
  unless limit.nil?
    n = limit.to_i
    if n.zero?
      parts = []
    elsif n.positive? && n < parts.length
      parts = parts[0...n]
    end
  end
  parts
end

#spread_attrs(bag) ⇒ Object

JSX intrinsic-element spread (#1407)

Mirrors the JS spreadAttrs runtime and the Go/Perl adapters' spread helpers so SSR output stays byte-equal across adapters. Generated ERB templates invoke this as <%= bf.spread_attrs(bag) %>.

Skip rules: nil/false values, event handlers (on[A-Z]...), and children. ref is intentionally NOT filtered (matches the JS reference). Key remap: className -> class, htmlFor -> for; SVG camelCase attrs preserved; other camelCase keys lowered to kebab-case. style routes through style_to_css. Output is deterministic: keys are sorted alphabetically before emission.

Unlike the Perl/Go ports, no boolean-sentinel detection is needed -- Ruby's true/false are real booleans, distinct from 0/1, so a bag value's Ruby class alone tells JS-boolean from JS-number.



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# File 'lib/barefoot_js.rb', line 1382

def spread_attrs(bag)
  return '' unless bag.is_a?(Hash)

  parts = []
  bag.keys.sort_by(&:to_s).each do |key|
    key_s = key.to_s
    if key_s.length > 2 && key_s.start_with?('on')
      c = key_s[2]
      next if c.upcase == c
    end
    next if key_s == 'children'

    val = bag[key]
    next if val.nil?

    if val.is_a?(TrueClass) || val.is_a?(FalseClass)
      next unless val

      parts << to_attr_name(key_s)
      next
    end

    if key_s == 'style'
      css = style_to_css(val)
      next if css.nil? || css.empty?

      parts << %(style="#{html_escape(css)}")
      next
    end

    parts << %(#{to_attr_name(key_s)}="#{html_escape(string(val))}")
  end
  return '' if parts.empty?

  # Mark the result raw so the calling template's plain `<%=` doesn't
  # need a second escape pass (the backend decides how "raw" is
  # represented for its engine; ERB's own emit has no auto-escape, so
  # BarefootJS::Backend::Erb's `mark_raw` is the identity function).
  backend.mark_raw(parts.join(' '))
end

#starts_with(recv, prefix, position = nil) ⇒ Object

String.prototype.startsWith(prefix, position?).



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# File 'lib/barefoot_js.rb', line 1124

def starts_with(recv, prefix, position = nil)
  s = recv.nil? ? '' : string(recv)
  p = prefix.nil? ? '' : string(prefix)
  unless position.nil?
    n = clamp_index(position.to_i, s.length)
    s = s[n..] || ''
  end
  s.start_with?(p)
end

#streaming_bootstrap ⇒ Object

Streaming SSR (Out-of-Order)



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# File 'lib/barefoot_js.rb', line 396

def streaming_bootstrap
  %{<script>(function(){function s(id){var a=document.querySelector('[bf-async="'+id+'"]');var t=document.querySelector('template[bf-async-resolve="'+id+'"]');if(!a||!t)return;a.replaceChildren(t.content.cloneNode(true));a.removeAttribute('bf-async');t.remove();requestAnimationFrame(function(){if(window.__bf_hydrate)window.__bf_hydrate()})};window.__bf_swap=s})()</script>}
end

#string(value) ⇒ Object

JS String(v) mirror, EXCEPT nil renders as '' (not the literal "null") so an unset prop doesn't surface as literal text in user-facing HTML -- the same divergence the Go/Perl adapters document for their string helper. This is the canonical JS-ish stringifier used throughout this file (join, spread_attrs, h, reduce's string fold, ...).



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# File 'lib/barefoot_js.rb', line 429

def string(value)
  return '' if value.nil?
  return value ? 'true' : 'false' if value.is_a?(TrueClass) || value.is_a?(FalseClass)
  return Evaluator.number_to_string(value) if value.is_a?(Numeric)
  # JS `Array.prototype.toString` is `this.join(',')`, applied
  # recursively -- Ruby's `Array#to_s` (inspect-style, e.g. "[[1], [2]]")
  # would otherwise leak through here instead of the JS comma-join
  # (e.g. reached via `.flat(0)`'s shallow copy joined afterwards,
  # #2262).
  return value.map { |el| string(el) }.join(',') if value.is_a?(Array)

  value.to_s
end

#style_object(*pairs) ⇒ Object

Builds the CSS string for a style={{...}} JSX object-literal attribute (#2261) -- pairs alternates CSS key (always a compile-time-known literal), then value. A value that fails has_unsafe_style_value? (after JS-String()-style stringification) is DROPPED -- the whole key:value pair is omitted -- matching Hono's oracle behavior exactly. The final joined string is STILL HTML-escaped (mirroring Hono's own escapeToBuffer call on its accumulated style string) -- a "safe" value can still carry a literal "/'/& (e.g. a BALANCED-quote CSS string value like "hello" passes the structural scan) that would otherwise break out of the double-quoted style="..." attribute. Returns a SafeString so bf.h (which the emitter still wraps every dynamic value with) passes the already-escaped result through unchanged.



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# File 'lib/barefoot_js.rb', line 912

def style_object(*pairs)
  parts = []
  pairs.each_slice(2) do |key, value|
    v = string(value)
    next if has_unsafe_style_value?(v)

    parts << "#{html_escape(key)}:#{html_escape(v)}"
  end
  SafeString.new(parts.join(';'))
end

#text_end ⇒ Object 



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# File 'lib/barefoot_js.rb', line 187

def text_end
  '<!--/-->'
end

#text_start(slot_id) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 183

def text_start(slot_id)
  "<!--bf:#{slot_id}-->"
end

#to_fixed(value, digits = 0) ⇒ Object

Number.prototype.toFixed(digits) -- fixed-decimal string with zero-padding, rounding half toward +Infinity (matching round).



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# File 'lib/barefoot_js.rb', line 1084

def to_fixed(value, digits = 0)
  n = number(value)
  return 'NaN' if n.respond_to?(:nan?) && n.nan?
  return n.negative? ? '-Infinity' : 'Infinity' if n.respond_to?(:infinite?) && n.infinite?

  digits = 0 if digits.nil? || digits.negative?
  factor = 10.0**digits
  rounded = (n * factor + 0.5).floor
  format("%.#{digits}f", rounded / factor)
end

#trim(recv) ⇒ Object

String.prototype.trim().



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# File 'lib/barefoot_js.rb', line 1061

def trim(recv)
  return '' if recv.nil? || recv.is_a?(Array) || recv.is_a?(Hash)

  string(recv).gsub(/\A\p{Space}+|\p{Space}+\z/, '')
end

#trim_end(recv) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 1076

def trim_end(recv)
  return '' if recv.nil? || recv.is_a?(Array) || recv.is_a?(Hash)

  string(recv).sub(/\p{Space}+\z/, '')
end

#trim_start(recv) ⇒ Object

String.prototype.trimStart() / .trimEnd() -- the one-sided siblings of trim above (#2183 follow-up), same \p{Space} regex restricted to one side.



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# File 'lib/barefoot_js.rb', line 1070

def trim_start(recv)
  return '' if recv.nil? || recv.is_a?(Array) || recv.is_a?(Hash)

  string(recv).sub(/\A\p{Space}+/, '')
end

#truthy?(value) ⇒ Boolean

JS truthiness (falsy: false, nil, 0, NaN, ""). Delegates to the shared evaluator so template-emitted conditionals (if bf.truthy?(x)) and callback-body evaluation agree byte-for-byte.

Returns:

  • (Boolean) 


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# File 'lib/barefoot_js.rb', line 459

def truthy?(value)
  Evaluator.truthy?(value)
end

#uc(s) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 774

def uc(s)
  s.nil? ? '' : string(s).upcase
end

#use_context(name, default = nil) ⇒ Object 



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# File 'lib/barefoot_js.rb', line 162

def use_context(name, default = nil)
  stack = CONTEXT_STACKS[name]
  stack.empty? ? default : stack.last
end