Javascript Engine

Revision as of 13:23, 9 September 2024

Javascript static Engine object.
This object is frozen.

Methods

• output([value1 [, value2 [, ...]]])

Output data to console / log.
Concatenate parameters. Put a space between them.
Does nothing if the resulting string is empty.

Engine.output("1",1,"test");
Engine.output("1" + " " + 1 + " test");
// Output: "1 1 test"

• debug([level, ][value1 [, value2 [, ...]]])

Put a debug message in console / log.
Concatenate values. Put a space between them.
Does nothing if the resulting string is empty.
Debug level is handled if the first parameter is an integer value. Defaults to Engine.DebugNote otherwise.

// The following calls will produce the same debug message:
Engine.debug(Engine.DebugNote,"test","out");
Engine.debug(8,"test out");
Engine.debug("test" + " out");

• alarm([info, ]level, value1 [, value2 [, ...]])

Put a debug message. Emits an alarm if a callback is installed.
Concatenate values. Put a space between them.
Does nothing if the resulting string is empty.
Parameters:
info: Optional alarm extra information
level: Debug/Alarm level

Engine.alarm("myscript",Engine.DebugWarn,"Some warning");
// Run time error:
Engine.alarm("some text");
Engine.alarm("myscript",Engine.DebugWarn);
// No alarm, no debug message:
Engine.alarm("myscript",Engine.DebugWarn,"");

• sleep(seconds)

Sleep for a number of seconds.

• usleep(microseconds)

Sleep for a number of microseconds.

• yield()

Give up the currently running timeslice. Note that on some platforms it also sleeps for the operating system's scheduler resolution.

• idle()

Sleep for a system dependent period adequate for an idle thread.
On most operating systems this is a 5 msec sleep.

• restart([code [,gracefull]])

Stop and restart the engine and the entire program.
Parameters:
code: Optional return code of the program. Defaults to 0
gracefull: Optional. Attempt to wait until no plugin is busy
Return:
TRUE if restart was initiated, FALSE if exiting or no supervisor or 'allow_abort' is disabled in javascript.conf.

• dump_r([what])
• print_r([what])

Dump (recursive) current context or specified item methods and properties.
dump_r: Dump to string
print_r: Dump to output
Parameters:
what: Optional item (variable) to dump. Dump current context if missing
Return:
dump_r returns the string containing dumped data.

• dump_var_r(what[,flags])
• print_var_r(what[,flags])

Dump (recursive) specified item methods and/or properties.
dump_var_r: Dump to string
print_var_r: Dump to output
Parameters:
what: Variable to dump
flags: Configure dump contents
May be an ORed combination of the following values:
Engine.DumpProp: Dump object properties
Engine.DumpFunc: Dump object functions
Engine.DumpRecursive: Dump contained objects also
Engine.DumpType: Dump type (applies to functions also)
Engine.DumpProto: Dump object prototype
Engine.DumpPropObjType: Dump non basic type if the following conditions are met: Engine.DumpProp flag is set, Engine.DumpFunc is not set, Engine.DumpType is not set
Predefined combinations:
Engine.DumpPropOnly: Engine.DumpRecursive | Engine.DumpPropObjType | Engine.DumpProp
Engine.DumpFuncOnly: Engine.DumpRecursive | Engine.DumpProto | Engine.DumpFunc
Defaults to Engine.DumpPropOnly
Return:
dump_var_r returns the string containing dumped data.

• dump_root_r([flags])
• print_root_r([flags])

Same as dump_var_r / print_var_r. obj is the script context

• dump_t(table[,hdrpMap[,params]])
• print_t(table[,hdrpMap[,params]])

Dump table to string or output.
The table may be an array of objects or an object containing arrays.
Array:
- Array of objects: each entry describe a new row. Object fields are column names.
- Array of arrays: Each entry describe a new row. First array contains column names.
Object: Each array field describe a column. Field name is the column name.
Parameters:
table: Table to dump
hdrMap: Header name mapping. Object with prop[header name in table]=value[new header display name]. Fields will be re-arranged as found in header mapping. New header display name may be empty if the list is only used to re-arrange fields
params: Dump parameters parameters

• force_empty: Boolean (default: false). Dump table with empty contents (no rows). Ignored if there are no header names
• all_headers: Boolean (default: false). Add the rest of the headers not found in 'hdrMap'. Ignored if 'hdrpMap' is not given

Return:
dump_t returns the string containing dumped data.

a = [{name1:"val11", name2:"val12"}, {name1:"val21", name3:"val23"}];
a2 = [["name1","name2","name3"], ["val11","val12" ],["val21",undefined,"val23"]];
o = {name1:["val11","val21"], name2:["val12"], name3:[null,"val23"]};
Engine.print_t(a);
Engine.print_t(a2);
Engine.print_t(o);
// Same output:
// name1 name2 name3
// ----- ----- -----
// val11 val12
// val21       val23

• debugName([name])

Set the debug name.
Retrieve debug name if no parameter is given.
Parameters:
name: Debug name to set

• debugLevel([level])

Set the debug level.
Retrieve the debug level if no parameter is given.
Parameters:
level: Debug level to set. Ignored if not an integer value

• debugEnabled([on])

Toggle (set) the debug enabled flag.
Retrieve the debug enabled flag if no parameter is given.
Parameters:
on: TRUE to enable debug output, FALSE to disable it

• debugAt(level)

Check if the current debug level of the module/script is greater or equal to requested level.
Parameters:
level: Integer value to check
Return:
TRUE if the current debug level greater than or equal to level, FALSE otherwise.

• setDebug(command)

Set debug according to command values.
Handled commands:
- level <level_value>: Set debug level to requested level value
- reset: Reset debug level to javascript module debug level
- engine: Reset debug level and debug enabled flag to yate engine settings
- boolean: Set debug enabled flag
All other values are ignored.

• started()

Check if engine is started at the time this method is called (engine.start message was sent).
Return:
TRUE if engine was started (all modules were loaded and initialized), FALSE if not.

• runParams([param])

Retrieve engine list of parameters specific to this run or a specified one.
Parameters:
param: Optional name of parameter to retrieve
Return:
Object with fields set to engine parameters or string with requested parameter value.

• configFile(name [,user])

Retrieve the full path of a configuration file. Add the '.conf' extension to name.
Parameters:
name: Configuration file name
user: Optional. Set it to TRUE to build the path from user settings
Return:
Path to requested file.

• setInterval(callback, milliseconds[,callback_args...])
• setTimeout(callback, milliseconds[,callback_args...])

Install a timer event. Request 'callback' function call on given interval.
setInterval: Repeat function call on requested interval.
setTimeout: Remove timer after first call.
Parameters:
callback: Function to call
milliseconds: Timer interval in milliseconds
callback_args: Optional arguments to be passed to callback function
Return:
Timer id.

• clearInterval(id)
• clearTimeout(id)

Remove requested timer.
Parameters:
id: Timer id to remove
Return:
TRUE on success, FALSE if not found.

• setEvent(callback,type[,params[,callback_args...])

Set an event to be signaled to script.
Parameters:
callback: Callback function
type: Event type (name or integer value)
params: Event setup parameters (object, optional)
callback_args: Optional arguments to be passed to callback function
Return:
Event numeric id, FALSE on failure.

Event type:

• reinit string or Engine.EventReInit property value. Setup a callback for javascript module initialize event.
  

May be used when a script wants to be notified on javascript module initialize (e.g. if it wants to detect the number of script instances when changed)

Callback is called from internal processing thread before any timer event

This event is available in static (loaded from config) and dynamic (loaded using javascript eval command) scripts

Event setup parameters:

• repeat. Repeat event. Boolean (default: true)

• clearEvent(id)

Clear an event se using setEvent().
Parameters:
id: Event id
Return:
TRUE on success, FALSE on failure (not found).

• loadLibrary(name [,name1 ...])
• loadObject(name [,name1 ...])

Load an object (loadObject) or a set of objects (loadLibrary) into script context.
These methods can be used to load custom C++ objects exposed to javascript.
An example of such module can be found in modules/test/jsext.cpp.
Parameters:
name: Library of object name(s). Single name or comma separated list
Return:
TRUE on success, FALSE on failure (library/object) not given or not found.

// The following load objects defined in jsext module:
loadLibrary("jsext");
loadObject("ExtObj");
// Unsafe to check return value:
ok = loadLibrary("lib1","lib2","lib3");
if (!ok) {
    // Unsafe: the list may be partially loaded. e.g. lib1 and lib3 loaded but not lib2
}

• replaceParams(buf, params [,sqlEscape [,extraEsc]])

Replace ${paramname} instances in 'buf' string from 'params' field values.
Parameters:
buf: String containing the replacements
params: Object whose fields are used to replace
sqlEscape: Optional. True to apply SQL escaping to parameter values
extraEsc: Character to escape other than the SQL default ones
Return:
String with replacements done. 'buf' if 'params' is an invalid object.

 params = {a:"first", b:"second", c:"not found"};
 s = "Test a=${a} empty=${missing} b=${b}";
 repl = Engine.replaceParams(s,params);
 // repl: "Test a=first empty= b=second"

• atob

Decode Base64 data.
Parameters:
b64_str: Mandatory, Base64 encoded data
Return:
Decoded data, boolean false on failure (invalid Base64 data)

str = Engine.atob(b64_str)

• btoa

Encode string data to Base64.
Parameters:
str: Mandatory, data to encode
line_len: Optional line length (split encoded data, add end of line after each line_len chars)
add_eol: Optional, add an extra end of line after encoded data
Return:
Base64 encoded data

b64_str = Engine.btoa(str[,line_len[,add_eol]])

• atoh

Decode Base64 data.
Parameters:
b64_str: Mandatory, Base64 encoded data
hex_sep: Optional separator to use between octets. Set it to 'undefined' if not used and hex_upcase is given
hex_upcase: Optional, use upper case characters in hexa
Return:
Hexified string, boolean false on failure (invalid Base64 data)

hex_str = Engine.atoh(b64_str[,hex_sep[,hex_upcase]])

• htoa

Encode hexified binary (string) data to Base64.
Parameters:
hex_str: Mandatory, data to encode
line_len: Optional line length (split encoded data, add end of line after each line_len chars)
add_eol: Optional, add an extra end of line after encoded data
Return:
The string, boolean false on failure (invalid input string).

b64_str = Engine.htob(hex_str[,line_len[,add_eol]])

• btoh

Convert binary (string) data to hexified string.
Parameters:
str: Mandatory, data to hexify
hex_sep: Optional separator to use between octets. Set it to 'undefined' if not used and hex_upcase is given
hex_upcase: Optional, use upper case characters in hexa
Return:
Hexified string

hex_str = Engine.btoh(str[,hex_sep[,hex_upcase]])

• htob

Unhexify binary (string) data.
Parameters:
hex_str: Mandatory, data to unhexify
hex_sep: Optional separator between octets. Set it to 'undefined' if missing or unknown (autodetect)
Return:
The string, boolean false on failure (invalid input string).

str = Engine.htob(hex_str[,hex_sep])

• hexByte(hex_str[,offset]

Convert at most 2 hexadecimal digits to integer value.
Parameters:
hex_str: String
offset: Optional, integer with offset in string to start from, negative to calculate offset from string end. Deault: 0
Return:
Success: Integer value in interval [0..255]
Failure: NaN. Reason: offset is past string length or at least one character is not a hexadecimal digit

• instanceIndex()

Retrieve the script instance index.
Return: calling script instance index. 0 (single instance) or greater than 0 if multiple instances are configured

See Javascript module configuration on how to configure multiple script instances.

• instanceCount()

Retrieve the number of configured script instance(s).
Return: calling script instance(s) count (at least 1)

See Javascript module configuration on how to configure multiple script instances.

• scriptType()

Return:
Calling script type numeric value. See Engine properties section.

Values:
Engine.ScriptTypeUnknown Unknown
Engine.ScriptTypeStatic Script was loaded from configuration
Engine.ScriptTypeDynamic Script was loaded using javascript load command
Engine.ScriptTypeMsgHandler Script is running a singleton message handler context
Engine.ScriptTypeEval Script is running was loaded using javascript eval command
Engine.ScriptTypeRoute Script is running a singleton routing context (see the routing option of javascript config)

• scriptInfo()

Retrieve script info description.
Return: Object

Properties.
type Numeric. See scriptType() return value
type_name String. Associated script type name: static,dynamic,handler,eval,route. Empty for unknown type

Properties

• DebugFail, DebugTest, DebugGoOn, DebugConf, DebugStub, DebugWarn, DebugMild, DebugCall, DebugNote, DebugInfo, DebugAll

Debug levels to be used when calling Engine.debug() or Engine.alarm().
NOTE:: Debug level is clamped to interval [DebugTest .. DebugAll] unless 'allow_abort' is enabled in javascript.conf (in this case the debug level is clamped to interval [DebugFail .. DebugAll].

• shared

Provides access to Shared object.

• name

Script name. It may not be available.
This is the name assigned to the script.
This property is missing when running javascript eval command.
Example:

javascript.conf:
[scripts]
test=some_script.js

in some_script.js
Engine.name property value is "test"

• EventReInit

Value(s) to be passed to setEvent() function in type parameter.

• ScriptTypeUnknown, ScriptTypeStatic, ScriptTypeDynamic, ScriptTypeMsgHandler, ScriptTypeEval, ScriptTypeRoute

Values returned by scriptType() function.

• DumpPropOnly, DumpFuncOnly, DumpFunc, DumpProp, DumpRecursive, DumpType, DumpProto, DumpPropObjType

Value(s) to be passed to dump_var_r(), print_var_r(), dump_root_r(), print_root_r() functions in flags parameter.