Class: GithubbishAssets::JSMinimizer

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

Constant Summary collapse

EOF = 
-1

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#input ⇒ Object

Returns the value of attribute input.



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# File 'lib/vendor/js_minimizer.rb', line 37

def input
  @input
end

#output ⇒ Object

Returns the value of attribute output.



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# File 'lib/vendor/js_minimizer.rb', line 38

def output
  @output
end

Class Method Details

.minimize_content(content) ⇒ Object 



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# File 'lib/vendor/js_minimizer.rb', line 207

def self.minimize_content(content)
  js_minimizer = new
  js_minimizer.input = StringIO.new(content)
  js_minimizer.output = StringIO.new
  
  js_minimizer.jsmin
  
  js_minimizer.output.string
end

Instance Method Details

#action(a) ⇒ Object

action – do something! What you do is determined by the argument: 1 Output A. Copy B to A. Get the next B. 2 Copy B to A. Get the next B. (Delete A). 3 Get the next B. (Delete B). action treats a string as a single character. Wow! action recognizes a regular expression if it is preceded by ( or , or =.



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# File 'lib/vendor/js_minimizer.rb', line 108

def action(a)
    if(a==1)
        @output.write @theA
    end
    if(a==1 || a==2)
        @theA = @theB
        if (@theA == "\'" || @theA == "\"")
            while (true)
                @output.write @theA
                @theA = get
                break if (@theA == @theB)
                raise "Unterminated string literal" if (@theA <= "\n")
                if (@theA == "\\")
                    @output.write @theA
                    @theA = get
                end
            end
        end
    end
    if(a==1 || a==2 || a==3)
        @theB = mynext
        if (@theB == "/" && (@theA == "(" || @theA == "," || @theA == "=" ||
                             @theA == ":" || @theA == "[" || @theA == "!" ||
                             @theA == "&" || @theA == "|" || @theA == "?" ||
                             @theA == "{" || @theA == "}" || @theA == ";" ||
                             @theA == "\n"))
            @output.write @theA
            @output.write @theB
            while (true)
                @theA = get
                if (@theA == "/")
                    break
                elsif (@theA == "\\")
                    @output.write @theA
                    @theA = get
                elsif (@theA <= "\n")
                    raise "Unterminated RegExp Literal"
                end
                @output.write @theA
            end
            @theB = mynext
        end
    end
end

#get ⇒ Object

get – return the next character from input. Watch out for lookahead. If the character is a control character, translate it to a space or linefeed.



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# File 'lib/vendor/js_minimizer.rb', line 55

def get()
  c = @input.getc
  return EOF if(!c)
  c = c.chr
  return c if (c >= " " || c == "\n" || c.unpack("c") == EOF)
  return "\n" if (c == "\r")
  return " "
end

#isAlphanum(c) ⇒ Object

isAlphanum – return true if the character is a letter, digit, underscore, dollar sign, or non-ASCII character



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# File 'lib/vendor/js_minimizer.rb', line 46

def isAlphanum(c)
   return false if !c || c == EOF
   return ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') ||
           (c >= 'A' && c <= 'Z') || c == '_' || c == '$' ||
           c == '\\' || c[0] > 126)
end

#jsmin ⇒ Object

jsmin – Copy the input to the output, deleting the characters which are insignificant to JavaScript. Comments will be removed. Tabs will be replaced with spaces. Carriage returns will be replaced with linefeeds. Most spaces and linefeeds will be removed.



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# File 'lib/vendor/js_minimizer.rb', line 157

def jsmin
    @theA = "\n"
    action(3)
    while (@theA != EOF)
        case @theA
        when " "
            if (isAlphanum(@theB))
                action(1)
            else
                action(2)
            end
        when "\n"
            case (@theB)
            when "{","[","(","+","-"
                action(1)
            when " "
                action(3)
            else
                if (isAlphanum(@theB))
                    action(1)
                else
                    action(2)
                end
            end
        else
            case (@theB)
            when " "
                if (isAlphanum(@theA))
                    action(1)
                else
                    action(3)
                end
            when "\n"
                case (@theA)
                when "}","]",")","+","-","\"","\\", "'", '"'
                    action(1)
                else
                    if (isAlphanum(@theA))
                        action(1)
                    else
                        action(3)
                    end
                end
            else
                action(1)
            end
        end
    end
end

#mynext ⇒ Object

mynext – get the next character, excluding comments. peek() is used to see if a ‘/’ is followed by a ‘/’ or ‘*’.



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# File 'lib/vendor/js_minimizer.rb', line 73

def mynext()
    c = get
    if (c == "/")
        if(peek == "/")
            while(true)
                c = get
                if (c <= "\n")
                return c
                end
            end
        end
        if(peek == "*")
            get
            while(true)
                case get
                when "*"
                   if (peek == "/")
                        get
                        return " "
                    end
                when EOF
                    raise "Unterminated comment"
                end
            end
        end
    end
    return c
end

#peek ⇒ Object

Get the next character without getting it.



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# File 'lib/vendor/js_minimizer.rb', line 65

def peek()
    lookaheadChar = @input.getc
    @input.ungetc(lookaheadChar)
    return lookaheadChar.chr
end