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Reference

AMIScript: Scripting

AMI Script Introduction

Overview

AMI has an embedded, versatile scripting language called AmiScript which combines syntax and functionality from Java, SQL, and string templating languages for flexible querying. AmiScript can be called anywhere within AMI, from the shell tool to datamodel creation.

Here is a very quick example of the language performing a cross-database join:

{
  //Inspect the ACCOUNTS table of two pre-defined databases (qadb & proddb).
  //Two temporary in-memory tables are created (qatemp and prtemp)
  String table = "ACCOUNTS";
  CREATE TABLE qatemp AS USE datasource=qadb   EXECUTE SELECT * FROM ${table};
  CREATE TABLE prtemp AS USE datasource=proddb EXECUTE SELECT * FROM ${table};

  //Gather some statistics, Note that the results of the queries on the in-memory tables are
  //stuffed into the local variables
  int qaCnt = select count(*) from qatemp;
  int prCnt = select count(*) from prtemp;
  int bothCnt = select count(*) from qatemp, prtemp where qatemp.id == prtemp.id;

  //Alert the user with some statistics, including the number of users in both qa and prod
  session.alert("Found ${qaCnt + prCnt} ${table} rows: ${qaCnt} in qa and ${prCnt} in prod. \
                 There are ${bothCnt} ids existing in both");

  //Create a Temporary ProdOnly table that contains all users in prod but not qa.
  //This table can be used in the visualization layer
  Create table ProdOnly as select * from prtemp where !(id in (select id from qatemp));
}
Note the interoperability of SQL and procedural style language as well as the dynamic string notation functionality (encased like so${...}).

Key Features

AmiScript

AmiScript is a versatile language designed for optimized "on the fly" compilation, meaning expressions can be re-compiled and evaluated in an instant.

Some key features of the language:

  1. Type Safe

    • All variables have well defined types, e.g: String, Integer, etc.
  2. Compile Time Binding

    • Code is compiled before execution to minimize runtime issues.
  3. Procedural

    • Custom methods (with overloading), along with a set of predefined procedures.
  4. Object Oriented

    • Objects in AMI are represented as such in AmiScript.
  5. Event Driven

    • Executes based on events, such as running a datamodel or clicking a button.
  6. Implicit Casting

    • Casting from one type to another can be explicitly or implicitly defined.
  7. Embedded SQL

    • For accessing external sources and tables directly in the language.
  8. String Templating

    • Ability to template code for reuse.
  9. Task Swapping

    • Tasks can be exported runtime for out-of-band execution (separate thread).

Embedded SQL

An SQL-style language extension to AmiScript with near-full SQL support along with several enhancements geared towards data preparation for the visualization of data. All of these functions act on an in-memory database. It also supports "calling out" to external datasources.

Some key features are:

  1. Query Clauses

    • For filtering, joining, and grouping data on the in-memory database.
  2. Data Modification

    • For adding, updating, and deleting data on the in-memory database.
  3. Schema Modification

    • For adding, editing, and deleting tables/columns on the in-memory database.
  4. Use ... Execute

    • For seamlessly running code on external datasources and storing results to the in-memory database.
  5. Advanced Data Preparation and Analysis

    • For complex data calculations, not typically available on a standard SQL database.
  6. Lambda Support

    • The ability to run AMI script code inside SQL.
    • For example, to run a code snippet per row returned in a table.
  7. Nested Queries

    • The in(...) clause supports full nested queries, and also supports multiple column in-clauses.
  8. Intelligent Indexing

    • As joins, in-claueses, etc. are evaluated, indexes will automatically be spun up depending on data size and cardinality.

AmiScript Template

AmiScript templating syntax is an extension of AmiScript with the aim of simplifying dynamic text generation, useful for creating dynamic HTML, dynamic SQL, etc.

  1. Embed Ami Script

    1. Inside text:
      • Embedding AmiScript inside text allows for easy dynamic text generation.
    2. Inside SQL:
      • Embedding AmiScript inside SQL allows for easy dynamic SQL generation.
  2. Injection Protection

    • Properly escaping control characters, quotes, etc.
  3. Conditional Templating

    • Ability to do conditional & loop based template construction.

Examples

Syntax

Same support as Java for control structures like loops, if/else statements, white space, comments and expressions:

double n = 0;
for(int i = 0; i < 10; i++){
    if(i < 5)
      n++;  //increment n
}

// same for loop replacing the if logic with the ternary operator, same as java
double n = 0;
for (int i = 0; i < 10; i++) {
    n += (i < 5) ? 1 : 0;   //increment n by 1 if i < 5
}

Data Structures

General purpose List, Map, Set & Table data structures are provided. The constructors can be used to prepopulate data:

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List mylist = new List(1,2,3,4);
Map mymap = new Map("fname","Eric","lname","Johnson");
Set set = new Set("a", "b", "c");
Table t = new Table("People", "user String, age int");

Type Safety & Coercion

Type names are case insensitive, e.g: double and DOUBLE are the same.

Other examples:

  • int and integer are the same
  • char and character are the same
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int n = 5;
Int m = n*n;
INTEGER o = m*m;

All types support null value. Dereferencing null, results in null. Expressions with null result in null.

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List l = null;
Integer s = l.size();   //s is null, does not raise null pointer
Double n = 5, m = null;
Double p = n*m;   //p is null because anything times null is null

Flexible type coercion. When coercion is not possible, the value is coerced to null.

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Int value = "123";    //value will be 123
Double value2 = new List();     //list can't be cast to double so value2 will be null
String value3 = new List(1,2,3);      //value3 is the string [1, 2, 3]

All types extend the AmiScript class Object and casting is not necessary for assignment.

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Object o = new List(1,2,3);
List l = o;   //this works because the value of o is a List.
Map m = 0;  //m will be null because a List can not be cast to a map

All types can be thrown/caught and all blocks can have catch clauses (try key word is not necessary).

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{
  throw "error";
} catch(String s) {
  session.alert("caught!"); //or any other logic
}

String Templates

If strings contain a ${...}, the content of the curly brackets is interpreted.

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String name = "rob";
String message1 = "hello ${name}";  // hello rob
String message2 = "A baker's dozen is {12+1}";  // A baker's dozen is 13

String Template Example

In this example, we will use string templates to access and evaluate variables from amiscript and pass them to a div field.

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string topHeaderName = "Top Header";
string subHeaderName = "Sub Header";

string scripts = "<h1>${topHeaderName}</h1>  <h3>${subHeaderName}</h3>";
div.setValue(scripts);

Alternatively, you could also use string template inside the div field:

<h1>${__USERNAME}</h1>  <h3>${__USERNAME+"123"}</h3>

You can use triple quotes for literals:

String m="""hello ${world}"""; // hello ${world}

SQL

There are several reserved words that indicate an SQL statement, including CREATE, SELECT, INSERT, DELETE, etc.

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CREATE TABLE t (username String, id int);
INSERT INTO t values ("rob",111),("dave",222);   //table t has 2 rows
CREATE TABLE t2 as select * from t where id<200;  //table t2 has 1 row

Variables and templates can be used inside SQL:

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String name = "eric";
Int id = 333;
INSERT INTO t VALUES (name, id);   //inserts eric, 333
String row = "values (\"mike\", 444)";   //ensure to escape the ""
INSERT INTO t ${row};   //expands to INSERT INTO t values("mike", 444); 

Table coercion works for Table cells to Objects, Columns to Lists and Rows to Maps.

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String s = SELECT username FROM t WHERE id == 111;  //s= rob
List names = SELECT username FROM t;  //names= [rob, dave]
Map user = SELECT * from t WHERE id == 222;  //user= {username=dave, id=222}

To query external data sources run the USE ds= ... EXECUTE command.

CREATE TABLE t3 as USE ds = "mydatabase" EXECUTE SELECT * FROM ORDERS;
//ran the "SELECT * FROM ORDERS" SQL command on the mydatabase datasource and created a local table called t3

To upload data to external data sources run the USE ds= ... INSERT command.

USE ds = "targetdb" INSERT INTO TargetAccounts FROM USE ds="sourcedb" SELECT * from SourceAccounts;   //query all data from sourcedb's SourceAccounts table and insert into targetdb's TargetAccounts table

Custom Methods

Methods are static and must return a type. If a return is clause is not reached, the function returns null.

String combine(String s, String t) {

   if (s != null && t != null)

     return s + " " + t;

};

String s=combine("apple","orange");   //s is now apple orange
String t=combine("apple",null);   //t is null

Variable Naming

Variables are named containers for storing data in AMI. Like other object oriented programming languages, variables are typed (but all are derived from Objects) and are unique, case-sensitive combinations of the following characters:

  1. a-z
  2. A-Z
  3. _
  4. 0-9

where the first character must not be a number. For example, int some_int1 = 0;.

Alternatively, variables can be wrapped in back ticks (`), in which case all characters are supported, allowing for accessibility with external language references, or for using protected class names. For example:

  • int `integer` = 0;
  • int `#001` = 1;

Variables are declared with the following syntax (the value will default to null if an expression is not supplied):

Type <variable_name> <= object_value_or_expression>;
Type <variable_name> <= object_value_or_expression>, <another variable_name = another_object_value>, ...;

Literals (Constants)

digits Int constant
0xdigits Hex Int constant
0digits Octal Int constant
digitsL Long constant
0xdigitsL Hex long constant
0digitsL Octal long constant
digits.digits Float constant. Note, scientific (aka 'E') notation is supported
digits.digitsD Double constant. Note, scientific (aka 'E') notation is supported
"chars" String constant. Use backslash (\ to escape quotes, backslash (\) and other control chars, ex: \n. A string can be defined over multiple lines using a trailing backslash on all but the last line, note that preceding white space is trimmed out for subsequent lines. Please see String Templating for details on \${...} syntax
\n\r\t White space (token delimiter)

Reserved Type

All reserved types' values are immutable. Null is a valid value.

Long 64 bit signed whole number
Double 64 bit signed float
String Variable length string of UTF 8 characters
Integer 32 bit signed whole number
Float 32 bit signed float
Byte 8 bit signed whole number
Boolean boolean (true or false)
Number Base class for Long,Double,Integer,Float,Byte
UTC Timestamp with millisecond precision (since unix epoch)

Examples

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Integer i = 32;
Double d = 4.3, f = 132.d; //declaring multiple variables
Integer j = 0xaabcc;
String test = "hello world";
String Test = "Hello \
               world";     //Multi line 
Integer lng = 100000000000L;
Boolean flag = true;
Byte some_thing = null;

Casting

Variables are strongly typed, but casting can be explicit or implicit. If a cast fails, the result evaluates to null. Also, equality operations (==, <=, >=, >, <, !=) will also auto-cast when possible as well.

Examples

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String test1 = 123;    //implicit cast from integer to string 
String test2 = "0x123";//implicit cast from hexidecimal integer to string 
Double val = "123.32"; //implicit case for string to double 
Boolean b = "true";    //implicit cast from string to boolean
String val = (Integer) 123.d; //explicit cast from double to integer, then implicit cast to String
Boolean c = "test";    //Evaluates to null because the implicit cast from string to boolean is invalid
Byte d;                //Evaluates to null by default

Variable Scoping

Scopes are defined using statement blocks, which are denoted by curly brackets: {...}. Within a statement block, variables are only visible after they are declared. When statement blocks are nested inside other statement blocks, all variables declared in the outer block are visible within the inner block as long as the variable is declared before the inner block. A variable in the same scope cannot be re-declared when another variable with the same name is visible.

Examples

{
  Byte a;
  //a is visible;
  Byte b;
  //a & b are visible; 
  {
    Byte c;
    //a, b & c are visible;
    Byte d;
    //a, b, c & d are visible;
    {
      Byte e;
      //a, b, c, d & e are visible;
    }
    //a, b, c & d are visible;   
  }
  //a & b are visible;
  Byte a;   //Compiler error: a already exists and can not be redefined
}

Standard Operators

The operators below are ordered by significance.

math_expressions

(evaluates to num_int_expr type)

num_expr * num_expr multiplication
num_expr / num_expr division
num_expr % num_expr modulus (remainder)
num_expr + num_expr addition for numbers
num_expr - num_expr subtraction

binary_expressions

(evaluates to num_int_expr type)

int_expr ~ int_expr bitwise NOT
int_expr << int_expr signed bit shift left
int_expr >> int_expr signed bit shift right
int_expr >>> int_expr unsigned bit shift right
int_expr & int_expr bitwise AND
int_expr ^ int_expr bitwise XOR
int_expr ! int_expr bitwise OR

boolean_expressions

(evaluates to boolean)

! bool_expr boolean (logical) NOT
expr < expr less than (strings are case sensitive)
expr > expr greater than (strings are case sensitive)
expr <= expr less than or equal to (strings are case sensitive)
expr >= expr greater than or equal to (strings are case sensitive)
expr == expr equal to (strings are case sensitive)
expr != expr is not equal to (strings are case sensitive)
expr =~ regex matches regular expression (see Java Pattern for details)
expr !~ regex does not match regular expression (see Java Pattern for details)
expr ~~ simple_pattern simplified text matching. See Simplified Text Matching section.
expr && expr logical and. Short circuits if left expr returns false. Short circuits if right expr is const and false
expr || expr logical or. Short circuits if left expr returns true. Short circuits if right expr is const and true

string_expressions

(evaluates to boolean)

string_expr + expr String concatenation. Null values equate to empty string ("")

special_expressions

(expression) Force Order of operations
(type)statement Explicit cast to type. Note that a failed cast returns null. Also, casting is automatic, so it's not necessary
bool_expr ? tr_expr : fl_expr If bool_expr returns true, then evaluates to tr_expr, otherwise evaluates to fl_expr.

Examples

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Long n = (10 + 5) * 2;  //n is 30 
n += 5;                 //n is 35 
n = n/2;                //n is 17 
Boolean b = n>10;       //b is true (n is still 17)
b =! b;                 //b is false 
b = (b || true) && true;//b is true         
String test = "hello" + "world"; //test is helloworld

Assignment & Declaration

special

(evaluates to type)

new type(param[, param ...]) Object Creation
type var_name Variable declaration (Value is defaulted to null)
type var_name = expression Variable declaration and assignment
Variable declaration and assignment Variable declaration and assignment

assignment (evaluates to num_var type)

num_var ++ combined post-increment assignment
++ num_var combined pre-increment assignment
num_var -- combined post-decrement assignment
-- num_var combined pre-decrement assignment
num_var *= num_expr combined multiplication assignment
num_var /= num_expr combined division assignment
num_var %= num_expr combined modulus assignment (remainder)
num_var += num_expr combined addition assignment
num_var -= num_expr combined subtraction assignment

Flow Control

Complex AMI scripts can be achieved by combining multiple statements into statement blocks. A statement block is wrapped in curly brackets {...} and each statement is separated with a semi-colon;. Then, the execution of statement blocks can be determined using a variety of flow control statements including if, if/else, for, while, and for-each-loops. Note that for and while loops can use the continue and break directives as well.

Examples

{
  Integer count = 10;
  Integer value = 1;
  for(Integer i = 0; i < count; i++){
    value *= 2;
  }
  if(value < 2000) {
    session.alert(value); //alert shows 1024
  } else   
    session.alert("High value"); // this is never hit. Also note: single statements don't need to be in {...} statement blocks
  while(true){
    value -= 10;
    if(value < 1000)
      break;
  }
  //value is now 994 
}

statement block

{ statement [;statement ...] [;]}

Evaluates to return value if a return_statment exists, otherwise it evaluates to the last statement's evaluation. If no statements, evaluates to Void

for loop

for(initialization;termination_expression;increment) statement
initialization
statement that is called first, used to declare variables with local scope
termination_expression
statement that must evaluate to boolean, false terminates
increment
statement called after each completion of the loop's statements
statement

called once per loop. Note:

  • continue_statement will exit the statement and proceed to increment statement
  • break_statement will exit the for loop entirely

Evaluates to Void

for each loop

for(type_expr  varname:iterable_or_array) statement
iterable_or_array
values to iterate over in order
statement

called once per loop. Note:

  • continue_statement will exit the statement and proceed to increment statement
  • break_statement will exit the for loop entirely

Evaluates to Void

while loop

while(bool_expression) statement

Same as for(;bool_expression;) statement

Evaluates to Void

if statement

if(bool_expression) statement

if bool_expression evaluates to true then execute statement

Evaluates to Void

if else statement

if(bool_expression) statement else statement2

if bool_expression evaluates to true then execute statement otherwise execute statement2

Evaluates to Void

return statement

return statement

Evaluates to statement's value. Will cause call stack to be popped out to caller function.

break statement

break

See for_loop, for_each_loop and while_loop.

continue statement

continue

See for_loop, for_each_loop and while_loop.

function call

function(param[, param ...])

Evaluates to return_type value

member method call

target_object.function(param[, param ...])

Evaluates to return_type value

Objects

There is a predefined set of object types (classes). These are used to facilitate the interaction between AMI Script and various backend components, user inputs, dashboards, etc. Additionally, data structures are represented as objects and can be instantiated using the new operator. Objects can only be accessed via methods (not member variables).

The Session Object

session - each user that is logged in has a session object (which is of type Session). This is the "starting point" for access to the user's information, along with various dashboard components.

Attributes and Class Methods for a Session Object

  1. session values: A hash map that stores user defined variables in the format of Variable_name_key=variable_value. Initially it is an empty map.

    1. session.setValue(string key, object value) && session.getValue(string key) && session.getValues()
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    int a = 3;
    session.setValue("sessionVal_a",a); //setting a to the session value
    session.getValue("sessionVal_a"); //getting the session value by the key
    
    int b = 4;
    session.setValue("sessionVal_b",b); //setting b to the session value
    
    session.getValues(); //{sessionVal_a=3, sessionVal_b=4}
    
  2. session variables: A list of variables that are predefined by dashboard and webserver. They cam be viewed from Dashboard -> Session Variables

    The dashboard editor can also define custom session variables by clicking Add variable. These are saved as part of the dashboard layout file

    Now this variable that we just defined is accessible everywhere in the current session.

  3. session global properties: these are server properties defined in the default.properties, local.properties and all other properties files

    1. session.getGlobalProperty(string propertyKey)
    session.getGlobalProperty("ami.components");
    

  4. session Properties: another way to access session variables

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    //Suppose there is a session variable called "a", the two ways below for accessing "a" are equivalent
    session.log(session.getProperty("a")); 
    session.log(a);
    

Common Data Structures

List: A zero-indexed Array List implementation

Set: A set of unique values

Map: A Linked Hash Map implementation

Table: A 2-dimensional table with the same characteristics as a SQL style table. Tables have a title. Columns are named and strongly typed.

Tableset: A map of tables. Can be loosely thought of as a mini database.

Examples

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session.alert("this is a test");
session.log("something worth logging);
List l = new List("apple", "orange", "berry", "banana");
l.splice(1, 2, "strawberry");
String s = l;                                //s is now apple, strawberry, banana
Map m = new Map(1, "one", 2, "two", 3, "three");  //map contains three key/value pairs, ex: 2 = "two"

Commenting

Commenting is identical to the commenting syntax in Java & C++. There are two types of comments: single-line and multi-line.

comments (single-line)

//comments<linefeed>

comments (multi-line)

/*comments*/

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/*multi-line
comment using the
slash stars*/
//single-line comment

AMIScript Constants

AMI Script can reference constants just like other variables. Note the constant's values can not be changed using AMI Script. The standard naming convention for global variables is 2 under bars (__) followed by an all uppercase name. Constants can be defined in three ways:

  1. At the server level (via a config file loaded at startup, typically local.properties)

    Typically the syntax is: amiscript.variable.varname=value

    (note that if value is a string, is must be surrounded in double quotes, see literals for details)

    For example, this could reside in your local.properties:

    #My custom variables

    amiscript.variable.__COMPANY_NAME="Acme Technologies"

    amiscript.variable.__COPYRIGHT=2017

  2. At the user level (using the authentication plugin, or the access.txt file)

    Typically the syntax is: {=html}amiscript.variable.varname=value

    (note that if value is a string, is must be surrounded in double quotes, see literals for details)

    For example, this could reside in your access.txt file for user demo (with password demo123):

    demo|demo123|amiscript.variable.__GROUP="infosec"|amiscript.variable.__SECURITY_LEVEL=12

  3. There are also pre-determined variables defined by the AMI Web system:

    • __USERNAME: (String) the username of the logged in user
    • __SESSIONID: (String) a unique id for the web session
    • __TIMEZONE: (String) the timezone of the user's session
    • __ADDRESS: (String) the ip address of the user's browser
    • __LOADTIME: (Long) the time in milliseconds that the user started the session
    • session: (Session) the session object representing the user's session

Hint: Through the front end in editor mode you can view all declared constants via: Menu Bar -> Dashboard -> Variable Table

Simplified Text Matching

Overview

The simplified text matching finds text entries using a simple pattern. When included in AMI script, it takes the form: var ~~ "my pattern"

Rule 1, the general case: the pattern supplied will match any text that contains the pattern, case insensitive. For example, assuming word is a variable let's consider the expression: word ~~ "AB". This will return true if word is cab or ABC or tabs but will return false if word is apple.

Rule 2, special symbols: If you need to look for symbols besides letters, numbers or white space, prefix with a back slash. For example, to look for the word P&L, the expression is word ~~ "P\\&L". Remember, we are in a string so a double back slash evaluates to a single backslash. Note this includes the following list of symbols: *^$.[]()\\|&!?:

Rule 3, Additional syntax: There are many special symbols that can be used for more advanced searches, for example the star (*) means anything, so "f*r" will match any thing that has an f followed by r, such as 3FORGE. See the following sections for more advanced syntax.

Syntax The following syntaxes are used to do "basic" matching against expressions with some text.

  1. Simple Matching Expression

    Matches any text that contains the supplied pattern regardless of case. The following characters are reserved and may be embedded in the expression:

    • * - Anything: Can be expanded to include any text.
    • ^ - Starts With: Symbolizes the "start" of the text. In other words, if an expression starts with ^, then the text must start with the following expression. Please note that carets (^) not at the start of the expression will be treated as literals. (When used in conjunction with the tilde (~), the hat should follow the tilde.)
    • $ - Ends With: Symbolizes the "end" of the text. In other words, if an expression ends with a dollar sign($) then the text must end with the preceding expression. Please note that dollar signs not at the end of the expression will be treated as literals.
    • . - Any single char.: each dot will disregard one character and checks for the target character(s) in the remaining string, case INsensitive.

    Examples:

    1. .s disregards the first character, checks for "s" OR "S" in the remaining string;
    2. s. attempts to find "s" OR "S" in the string. If found, disregards the next character and returns a match. If not found, returns empty;
    3. ..s disregards the first TWO characters, checks for "s" OR "S" in the remaining string. Return a match if "s" OR "S" is found, empty otherwise;
    4. ss.. attempts to find "ss" OR either one of ("sS", "SS", "Ss") (must be consecutive "s") in the string. When found, disregards the next two characters and returns a match;
    5. ..s.S.. disregards the first TWO characters, attempts to find one "s" OR "S", if found, disregard the next character, then attempts to find another "s" OR "S" in the remaining string, if found, disregards the next two characters and returns a match. If "s" was not found in either one of the two scenarios, return empty.
    6. Note that the evluation order is always from left to right. Each character is checked at most once.
    7. [charlist] Any of Chars.: Match any one of the characters enclosed within the brackets.
    8. ~: Case Sensitive. Apply it before the first character. It indicates case sensitivity when matching the string.
    9. Escaped chars: When referencing the following characters literally, they must be escaped with a back slash (\): \*\^\$.\[\]()\~\|&!?:
    10. Literals: These are simply letter-for-letter matches to the expression
  2. 'Exact Expression'

    Matches the exact expression supplied in quotes (other than an escaped quote using \ ). This would be similar to using an equals ( == )

  3. /regex/<options>/

    This will use the java.util.regex package to match against regular expressions (see the java.util.regex.Pattern for details on building regular expressions). The <options> allow you to control behavior of how the regular expression operates. Simply supply the options you would like to apply in a continuous string between the 2nd and last forward slash (/). The following options are supported:

    • q - Canonical Equivalence: When this flag is specified, two characters will be considered to match if and only if their full canonical decompositions match. The expression "a\u030A", for example, will match the string "?" when this flag is specified. By default, matching does not take canonical equivalence into account.
    • f - Full Line: When this flag is specified, the text must fully match the regular expression. If this option is not specified, any portion of the text matching the expression will be considered a match.
    • i - Case Insensitive: By default, case-insensitive matching assumes that only characters in the US-ASCII charset are being matched. Unicode-aware case-insensitive matching can be enabled by specifying the u (Unicode case) flag in conjunction with this flag.
    • c - Comments: White space is ignored, and embedded comments starting with # are ignored until the end of a line.
    • l - Literal: White space is ignored, and embedded comments starting with # are ignored until the end of a line.
    • d - Disable Dot All: If the disable dot all flag is set then the dot expression (.) will match any character except a line terminator. By default, the dot expression only matches line terminators.
    • m - Multiline: In multiline mode the expressions ^ and $ match just after or just before, respectively, a line terminator or the end of the input sequence. By default, these expressions only match at the beginning and the end of the entire input sequence.
    • u - unicode Case: When this flag is specified, case-insensitive matching, enabled by the i (case insensitive) flag, is done in a manner consistent with the Unicode Standard. By default, case-insensitive matching assumes that only characters in the US-ASCII charset are being matched.
    • x - Unix Lines: In this mode, only the '\n' line terminator is recognized in the behavior of ., ^, and $.
    • v - Not Matching: Reverses the matching result. Expressions that normally would match will not match and expressions that would not normally match will match.
    • n - No Error: If the regular expression is invalid do not throw an exception, instead just always return false, unless the v flag is also set, in which case always return true.
  4. <null>

    Null String - providing null will result in a matcher which matches nothing.

  5. <Empty String>

    Providing an empty (zero length) string to the Matcher method will result in a matcher which matches only the empty string.

Conjugated Syntaxes

The following syntaxes allow for more complicated pattern matching. Nested syntaxes may also be conjugated syntaxes. For nested syntaxes which are basic syntaxes open parenthesis [ ( ] and close parenthesis [ ) ] must be escaped with a backslash [ \ ].

  1. (Expression): The parenthesis can be used to force order of operations, important when mixing or [ | ] and and [ & ] clauses.

  2. Expression1\|Expression2: If either of the nested expressions match this expression will return true.

  3. Expression1&Expression2: If both of the nested expressions match this expression will return true.

  4. !Expression: Inverts the result of the expression.

  5. (Expression) ? (ExpressionTrue) : (ExpressionFalse): If the Expression matches, return result of ExpressionTrue Otherwise return result of ExpressionFalse.

Sample Expressions

Expression Examples Match Examples Mismatch Comments
FORG 3Forge Frg Partial text, Case insensitive match
~FORG FORGE forge Partial text, Case sensitive match
^FORG$ FORG FORGE Exact text, Case insensitive match
~^Forge$ Forge forge Exact text, Case sensitive match
!FORG 3FOR 3FORGE Escape partial text, case insensitive
!^FORG$ FORGE FORG Escape exact text, case insensitive
[RB]ob Bobby lob Using char list
[A-Z]ob mob 7ob Char list range
3F*ge 3Forge llc Forge llc Wild chars
3f.ge 3Frge 3Forge llc Match single char
Acme llc. Acme llc. Acme llcc Escaping special chars
Rob|bob|dan robert ted Or clause partial match
^Rob$|^Dan$ rob robert Or clause, exact match
bob&rob robob bobob And clause partial
'Exact' Exact exact Exact case sensitive text match
a Empty string, only matches empty string
a?bb:s Abba acca ''If contains 'a', must contain 'bb'
a?bb:s test tent ''If doesn't contain 'a', must contain 's'
(a|b)&(e|f) af ab Must contain a or b. Also must contain e or f
'abc'|'def' def DEF Must be exactly 'abc' or 'def'
/reg/ regular Regular By default, regex must be case sensitive
/reg/i/ Regular whatever I option makes case insensitive
/req//|3F 3F 3Forge Mixing regex and non regex
/req//|3F reg Regular Mixing regex and non regex

String Templating

Goals

String templating is used to ease the dynamic creation of strings. Some key places that benefit from string templating:

  • HTML generation
  • SQL generation
  • Content-rich messages for the end user
  • Debugging / Logging

Basic Usage

As usual, strings are denoted using double quotes at the beginning and end, ex: "...". Within a string, ${...} is recognized as a special operator. The text between the curly braces is interpreted as code to be executed. For example, the code can be a simple variable name, or a complex set of expressions.

"text${code}text${code}..."

If you wish to include a literal dollar sign followed by a curly bracket, the dollar sign must be escaped with a backslash.

"test\${stilltext}text" // evaluates to: test${stilltext}text

To prevent against SQL (and other forms) of injections, ${...} wrapped with quotes ('), double quotes (") or back ticks (`) will cause the evaluated text to be escaped with a backslash (\) accordingly:

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"text '${code}'"      // result is ' escaped to \'
"text \"${code}\""    // result is " escaped to \"
"text `${code}`"      // result is ` escaped to \`

For example:

String foo = "Eric's";
String bar = "NAME LIKE '${foo}'";   // result is: NAME LIKE 'Eric\'s'

Finally, null will evaluate to an empty string "".

Examples

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Integer age = 20;
String name = "Sue";
String message2 = "${name} is ${age} year(s) old";     // Simple Case: Sue is 20 year(s) old
String t = "Four times four is ${4 * 4}";              // Complex Expression: Four times four is 16
String t2 = "40/9 is ${formatNumber(40/9d, "#.###")}"; // Calling functions: 40/9 is 4.444
String t2 = "don't replace \${name}";                  // Avoid Template: don't replace ${name}

String d = "ain't";                 
String m1 = "escaping '${d}' easy";                    // Evaluates to: escaping 'ain\'t' easy 

Templated Flow Control

The ${...} syntax can also be used to dictate if/how text should be included. This includes all flow control statements, including if-statements, for-loops, for-each-loops, and while-loops. All flow control statements are closed by the ${} token (empty curly brackets).

Flow Control Statement

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"[text]\
  ${flow_control(...)}\ 
    [text inside flow control]\
  ${}\
[text]"

Note: Definition is a multiline string for clarity

Single Line Flow Control Statement

"[text]${flow_control(...)}[text inside flow control]${}[text]"

Examples:

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"Count the apples: ${for(int i = 1; i <= 5; i++)} ${i} apple ${} There are 5 apples."
"Count the apples: ${int i = 1; while(i++ < 6)} ${i} apple ${} There are 5 apples."
"Count the apples: ${if(5 > 3)} apple apple apple apple apple ${} There are 5 apples."

For if/else use the reserved ${else} token:

If/else Statements

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"[text]\
  ${if(...)}\
    [text inside if statement]\
  ${else}\
    [text inside else statement]\
  ${}\
[text]"

Note: Definition is a multiline string for clarity.

Single Line If/else Statements

"[text]${if(...)}[text inside if statement]${else}[text inside else statement]${}[text]"

Example:

"Count the apples: ${if(5 < 3)} apple ${else} orange ${} There is one orange."

Flow control statements can be nested:

Nested Flow Control Statements

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"[text]\
  ${flow_control_outer(...)}\
    [text inside outer flow_control]\
    ${flow_control_inner(...)}\
      [text inside inner flow_control]\
    ${}\
    [text inside outer flow_control]\
  ${}\
[text]"   

Note: Definition is a multiline string for clarity.

Single Line Nested Flow Control Statements

"[text]${flow_control_outer(...)}[text inside outer flow_control]${flow_control_inner(...)}[text inside inner flow_control]${}[text inside outer flow_control]${}[text]"

Example:

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"Courses:\n \
    ${for(int i = 120; i < 122; i++)} \
      Course: Math${i}\n \
      ${for(int j = 1000; j < 1009; j++) } \
        Students${j}\n \
      ${} \
      Professor For Math${i}:Stern\n \
    ${}\
  ====End===="

Examples

List letters = new List("A", "B", "C");
  String s = "Easy as ${for(int i = 1; i <= 3; i++)} the number ${i} ${}";//Easy as 1 2 3
  String s2 = "${for(String i:letters)} ${i}${},
Easy as ${for(int i = 1; i <= 3; i++)} ${i} ${}";
  //s2 evaluates to: A B C, Easy as 1 2 3 

{
  Map messages = new Map();
  for(int num = 1; num <= 3; num++)
     messages.put(num,"=is ${if(num == 2)}exactly${else}not${} two");
  session.alert(messages); // Evaluates to: {1=is not two,2=is exactly two,3=is not two} 
}

Syntax for Embedding External Languages

Goals

  • Allow users familiar with other languages to embed familiar code into existing data models.
  • Enable users to take advantage of existing libraries found in other languages

Syntax

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extern language {{
       ...
       embedded_code_in_other_langauge
       ...
}};

Rules on Prefixing and terminating the custom code segment:

  • The prefix must be at least 2 consecutive opening curly brackets ({).
  • The termination must have the same number of closing curly brackets (}) as the prefix has.
  • You can not include the suffix inside the embedded code. So for example, let's say you have a }} inside the embedded code, then you should wrap the embedded code in three curly brackets, ex: {{{custom_code_witha_double_curlys}}}
  • The embedded code is evaluated literally, ex: all escapes, etc. are sent directly to the sub-language engine

Currently, python is supported out of the box.

Example

{
  int n=5;

  extern python {{
    for i in xrange(2,5):
      n=n*i;
  }};

  session.log(n);// will log 120
}

Formatting Timestamps

3forge provides two ways of handling timestamps when it comes to formatting:

  • User Settings: If you like to maintain a unified date/time format across the dashboard, the formatting can be configured via user settings. Simply navigate to Account -> My Settings

  • AMI Script Methods: If you like to have different formats in different places in the dashboard, AMI Script provides a handful of methods that can be utilized. To know more about their usage you can navigate to Help -> AMI Script Doc and the relevant methods will be available under AMI-Script Functions.

An example is provided below where an AMI Script Method has been used to format a table column.

Additionally, You can set the default timezone for all users by setting the property in local.properties:

ami.default.user.timeZone=EST5EDT

AMI Reserved WORDS (alphabetical)

ADD ALTER ANALYZE AND AS ASC BEFORE BINARY BOOLEAN BREAK BY CALL CASE CATCH CREATE CONCURRENT CONTINUE DEFAULT DELETE DESC DESCRIBE DISABLE DO DOUBLE DROP ELSE ENABLE EXECUTE EXTERN FLOAT FOR FROM GROUP HAVING IF IN INDEX INSERT INT INTEGER INTO JOIN LEFT LIMIT LONG MODIFY NEAREST NEW OFTYPE ON ONLY OR ORDER PARTITION PREPARE PRIORITY PROCEDURE PUBLIC RENAME RETURN RIGHT SELECT SET SHOW STEP STRING SWITCH SYNC TABLE TABLES TIMER TRIGGER TO TRUNCATE UNION UNPACK UPDATE USE UTC UTCN VALUES WHERE WHILE WINDOW

Reserved words are case insensitive