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function

Declare Object

SWF Action
Action Category: 
Objects
Action Details: 
0
Action Identifier: 
67
Action Structure: 
<n.a.>
Action Length: 
0 byte(s)
Action Stack: 
pop 1 (i), pop i1 × 2 (a), push 1 (o)
Action Operation: 
i1 := pop();
for(idx := 2; idx <= i1 * 2 + 1; ++idx) {
  aidx := pop();
}
o := new Object;
o.a3 := a2;
o.a5 := a4;
...
o.a(i1 × 2 + 1) := a(i1 × 2);
push(o);
Action Flash Version: 
5

Pop the number of members that will be created in the object. Pop one value and one name1 per member and set the corresponding member in the object. The resulting object is pushed on the stack. It can later be sent to a function, saved in a register or set in a variable.

  • 1. The member names are converted to strings; they certainly should be strings though anything is supported.

Declare Function (V7)

SWF Action
Action Category: 
Control
Action Details: 
(256 variables)
Action Identifier: 
142
Action Structure: 
string     f_name;
unsigned short   f_arg_count;
unsigned char   f_reg_count;
unsigned short   f_declare_function2_reserved : 7;
unsigned short   f_preload_global : 1;
unsigned short   f_preload_parent : 1;
unsigned short   f_preload_root : 1;
unsigned short   f_suppress_super : 1;
unsigned short   f_preload_super : 1;
unsigned short   f_suppress_arguments : 1;
unsigned short   f_preload_arguments : 1;
unsigned short   f_suppress_this : 1;
unsigned short   f_preload_this : 1;
swf_params   f_params[f_arg_count];
unsigned short   f_function_length;

WARNING: the preload/suppress flags are defined on a short and thus the bytes in a Flash file will look swapped.

Action Length: 
-1 byte(s)
Action Stack: 
n.a.
Action Operation: 
create a function on the current target
Action Flash Version: 
7

Declare a function which can later be called with the Call Function action or Call Method action (when defined as a function member.) The f_function_length1 defines the number of bytes that the function declaration uses after the header (i.e. the size of the actions defined in the function.) All the actions included in this block are part of the function body.

  • 1. A function is limited to 65535 bytes.

Declare Function

SWF Action
Action Category: 
Control
Action Details: 
0
Action Identifier: 
155
Action Structure: 
string    f_name;
unsigned short   f_arg_count;
string   f_arg_name[f_arg_count];
unsigned short   f_function_length;
Action Length: 
-1 byte(s)
Action Stack: 
n.a.
Action Operation: 
create function f_name in the current target movie
Action Flash Version: 
5

Declare a function which later can be called with the Call Function action. The f_function_length1 defines the number of bytes that the function declaration takes. All the actions included in this block are part of the function. A function should terminate with a Return action. The value used by the return statement should be the only value left on the caller stack.

  • 1. Functions are limited to 65535 bytes in length.

Declare Dictionary

SWF Action
Action Category: 
Objects
Action Details: 
0
Action Identifier: 
136
Action Structure: 
unsigned short    f_count;
string   f_dictionary[f_count];
Action Length: 
-1 byte(s)
Action Stack: 
n.a.
Action Operation: 
<n.a.>
Action Flash Version: 
5
See Also: 

Declare an array of strings that will later be retrieved using the Push Data action with a dictionary lookup. There can be a maximum of 65534 strings. The visibility of a dictionary is within its DoAction or other similar block of actions. Note that you should have only one Declare Dictionary. The dictionary is visible from everywhere in the DoAction.

Declare Array

SWF Action
Action Category: 
Objects
Action Details: 
0
Action Identifier: 
66
Action Structure: 
<n.a.>
Action Length: 
0 byte(s)
Action Stack: 
pop 1 (i), pop i1 (a), push 1 (array)
Action Operation: 
i1 := pop();
for(idx := 2; idx < i1 + 2; ++idx) {
  aidx := pop();
}
arr := new array(i1);
arr[0] := a2;
arr[1] := a3;
...
arr[i1 - 1] := a(i1 + 1);
push(arr);
Action Flash Version: 
5

Pops the number of elements in the array. Pop one value per element and set the corresponding entry in the array. The array is pushed on the stack. It can later be sent to a function or set in a variable.

To set the indices, use the Declare Object instead.

Chr

SWF Action
Action Category: 
String and Characters
Action Details: 
0
Action Identifier: 
51
Action Structure: 
<n.a.>
Action Length: 
0 byte(s)
Action Stack: 
pop 1 (i), push 1 (s)
Action Operation: 
i1 := pop();
r := chr(i1);
push(r);
Action Flash Version: 
4

Pops one integer, use it as a ASCII character and push the newly created string on the stack.

The function only works with ASCII characters: a number from 0 to 255, some of which will not work (especially 0).

To generate a USC character, use the multi-byte chr() instruction instead.

Call Method

SWF Action
Action Category: 
Control
Action Details: 
0
Action Identifier: 
82
Action Structure: 
<n.a.>
Action Length: 
0 byte(s)
Action Stack: 
pop 1 (s), pop 1 (o), pop 1 (i), pop i3 (a)
Action Operation: 
s1 := pop();
o2 := pop();
i3 := pop();
for(idx := 4; idx < i3 + 4; ++idx) {
  aidx := pop();
}
if(s1.length) {
  // call method s1
  r := o2.s1(a4, a5, a6...a(i3+3));
}
else {
  // call constructor o2
  r := o2(a4, a5, a6...a(i3+3));
}
push(r);
Action Flash Version: 
5

Pop the name of a method (can be the empty string), pop an object, pop the number of arguments, pop each argument, call the method (function) of the object, push the returned value on the stack.

When the string is empty, the constructor is called. This is used by the system right after a new operator was called and most of the time the return value is simply discarded.

Call Function

SWF Action
Action Category: 
Control
Action Details: 
0
Action Identifier: 
61
Action Structure: 
<n.a.>
Action Length: 
0 byte(s)
Action Stack: 
pop 1 (s), pop 1 (i), pop i2 (a), push 1 (a)
Action Operation: 
s1 := pop();
i2 := pop();
for(idx := 3; idx < i2 + 3; ++idx) {
  aidx = pop();
}
r := call s1(a3, a4, a5...a(i2+2));
push(r);
Action Flash Version: 
5

Pops one string that represents the name of the function to call, pop one integer indicating the number of arguments following, pop each argument, call the named function, push the result of the function on the stack. There is always a result1.

  • 1. When nothing is returned by the function, the result undefined is pushed on the stack.

Appendix B — History of the SSWF reference

Dec 2, 2009

Moved the monolithic documentation to a multi-page hierarchical document that includes everything we had before plus many links, many terms attached to all pages (tags, English words.) And revision of most of the text for better English and clarification in some places.

Strengthen the formatting with CCK fields so all declarations look alike.

Broken up the actions from one large table to a set of pages.

Dec 14, 2008

Started work on the Load() feature of the SSWF library. This helped fixing several small mistakes in the documentation.

May 18, 2008

Fixed the ...

SWF Params (swf_params)

SWF Structure Info
Tag Flash Version: 
7
SWF Structure: 
struct swf_params {
	unsigned char		f_param_register;
	string			f_param_name;
};

Since version 7 of SWF, there is a new way to create a function allows you to not only name parameters but also to put their content in a register. This is done by specifying a register number along an (optional) parameter name.

The f_param_register specifies whether the corresponding parameter will be saved in1:

  • 1. Note that "neither" is not an option, thus although both the register number and name are optional, at least one of them needs to be defined.