### Installation: Step 1

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/sitemap.html

First step in the installation process. This typically involves prerequisites or initial setup.

```bash
# Step 1: Download the installer
curl -O http://example.com/installer.tar.gz
```

--------------------------------

### Installation: Step 3

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/sitemap.html

Third step in the installation process. This might involve configuration or starting services.

```bash
# Step 3: Configure the environment variables
export FGLDIR=/opt/4js/fgl
```

--------------------------------

### Get Submatch Index All Example

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/fgl-topics/c_fgl_ext_util_Regexp_getSubmatchIndexAll.html

Demonstrates how to use getSubmatchIndexAll to find the start and end positions of all whole matches and their sub-matches within a string.

```fgl
IMPORT util
MAIN
    DEFINE re util.Regexp
    DEFINE arr DYNAMIC ARRAY WITH DIMENSION 2 OF INTEGER
    LET re = util.Regexp.compile(`([A-Z]*)([0-9]*)`)
    LET arr = re.getSubmatchIndexAll("ABC678EFG99")
    DISPLAY "First whole match:"
    DISPLAY arr[1,1], arr[1,2]
    DISPLAY arr[1,3], arr[1,4]
    DISPLAY arr[1,5], arr[1,6]
    DISPLAY "Second whole match:"
    DISPLAY arr[2,1], arr[2,2]
    DISPLAY arr[2,3], arr[2,4]
    DISPLAY arr[2,5], arr[2,6]
END MAIN
```

--------------------------------

### os.Path.mkDir example

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/index.html?q=%2Fonline_documentation%2Ffjs-fgl-manual-html%2Ffgl-topics%2Fc_fgl_dialog_AFTER_DISPLAY.html

Demonstrates creating a new directory at the specified path using os.Path.mkDir. It also shows how to check for existence before creation.

```fgl
DEFINE new_dir_path STRING

LET new_dir_path = "/path/to/new/directory"

IF NOT os.Path.exists(new_dir_path) THEN
  IF os.Path.mkDir(new_dir_path) = 0 THEN
    MESSAGE CONCAT("Directory created: ", new_dir_path)
  ELSE
    MESSAGE CONCAT("Failed to create directory: ", new_dir_path)
  END IF
ELSE
  MESSAGE CONCAT("Directory already exists: ", new_dir_path)
END IF
```

--------------------------------

### Java Interface

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/index.html?q=%2Fonline_documentation%2Ffjs-fgl-manual-html%2Ffgl-topics%2Fc_fgl_ClassChannel.html

Details on how to extend Genero FGL using the Java interface, including prerequisites, getting started, advanced programming techniques, and examples.

```APIDOC
## Java Interface

### Description
This section details the process of extending Genero FGL using the Java interface. It covers prerequisites, installation, getting started with basic operations like importing classes and calling methods, and advanced programming concepts.

### Prerequisites and Installation
* Learn about Java and OOP
* Java software requirements for FGL
* How to set up Java
* Platform-specific notes for the JVM

### Getting Started with the Java Interface
* Import a Java class
* Define an object reference variable
* Instantiate a Java class
* Calling a method of a class
* Calling a method of an object

### Advanced Programming
* Using JVM options
* Case sensitivity with Java
* Method overloading in Java
* Java objects as function parameters and returns
* Garbage collection of unused objects
* Using the method return as an object
* Ignorable return of Java methods
* Static fields of Java classes
* Mapping native and Java data types (DATE, DATETIME, DECIMAL, TEXT, BYTE, INTERVAL)
* Identifying Genero data types in Java code
* Using Genero records
* Formatting data in Java code
* Character set mapping
* Using Java arrays
* Passing variable arguments (varargs)
* The CAST operator
* The INSTANCEOF operator
* Java exception handling
* Troubleshooting Java interface issues
* Executing Java code with GMA (Standard Java and Android library usage, Implement Java user extensions in GMA, Implement Android™ activities in GMA, Packaging custom Java extensions for GMA)

### Examples
* Example 1: Using the Calendar package
* Example 2: Using the Apache POI framework
* Example 3: Using Java on Android™
```

--------------------------------

### Start Android Activity and Get Result

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/fgl-topics/c_fgl_frontcall_android_startactivityforresult.html

Invokes the barcode scanner application to scan a barcode and retrieves the scanned value. If the scanner app is not installed, it launches the Play Store to prompt the user to install it. The returned data is parsed from a JSON string.

```fgl
IMPORT util
...
DEFINE data, extras STRING,
       json_object util.JSONObject,
       scanned_value STRING
...
CALL ui.Interface.frontCall(
        "android", "startActivityForResult", 
        [ "com.google.zxing.client.android.SCAN",
          NULL, "android.intent.category.DEFAULT" ],
        [ data, extras ])
IF extras IS NULL THEN
  -- If the application isn't installed invoke 
  -- the Play Store to give the user a chance to install it
  CALL ui.Interface.frontCall("standard", "launchurl",
          ["market://details?id=com.google.zxing.client.android"], [])
ELSE
  LET json_object = util.JSONObject.parse(extras)
  -- Fetch the scanned value
  LET scanned_value = json_object.get("SCAN_RESULT")
END IF
```

--------------------------------

### Example: os.Path.mkDir

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/index.html?q=%2Fonline_documentation%2Ffjs-fgl-manual-html%2Ffgl-topics%2Fc_fgl_BuiltInFunctions_FGL_GETWIN_WIDTH.html

Shows how to create a new directory using the `os.Path.mkDir` method. It can create intermediate directories if they do not exist.

```fgl
MAIN
  DEFINE dir_path STRING = "/tmp/my_new_directory/subdir"
  DEFINE rc INTEGER

  -- Create the directory, including intermediate directories if needed
  LET rc = os.Path.mkDir(dir_path)

  IF rc == 0 THEN
    DISPLAY "Directory created successfully: ", dir_path
  ELSE
    DISPLAY "Failed to create directory. Error: ", os.Path.describeLastError()
  END IF
END MAIN
```

--------------------------------

### os.Path.dirOpen and os.Path.dirNext example

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/index.html?q=%2Fonline_documentation%2Ffjs-fgl-manual-html%2Ffgl-topics%2Fc_fgl_dialog_AFTER_DISPLAY.html

Demonstrates opening a directory for iteration using os.Path.dirOpen and reading directory entries one by one using os.Path.dirNext.

```fgl
DEFINE dir_handle INTEGER
DEFINE entry_name STRING
DEFINE dir_path STRING

LET dir_path = "/path/to/directory"

LET dir_handle = os.Path.dirOpen(dir_path)

IF dir_handle > 0 THEN
  MESSAGE CONCAT("Contents of ", dir_path, ":")
  LOOP
    LET entry_name = os.Path.dirNext(dir_handle)
    IF entry_name IS NULL THEN
      EXIT LOOP
    END IF
    MESSAGE entry_name
  END LOOP
  LET rc = os.Path.dirClose(dir_handle)
ELSE
  MESSAGE CONCAT("Failed to open directory: ", dir_path)
END IF
```

--------------------------------

### Get Previous Sibling Example

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/index.html?q=%2Fonline_documentation%2Ffjs-fgl-manual-html%2Ffgl-topics%2Fc_fgl_ui_tables_aggregates.html

Example of getting the previous sibling of a node.

```javascript
var node = xmlDoc.getElementById("nodeId");
var prevSibling = node.getPreviousSibling();
```

--------------------------------

### Get Attributes Count Example

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/index.html?q=%2Fonline_documentation%2Ffjs-fgl-manual-html%2Ffgl-topics%2Fc_fgl_form_responsive_hidden.html

Example to get the number of attributes on a node.

```javascript
var doc = new xml.DomDocument();
var element = doc.createElement("element");
element.setAttribute("attr1", "val1");

console.log(element.getAttributesCount()); // Output: 1
```

--------------------------------

### Example 1: SqlHandle with simple SQL

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/fgl-topics/c_fgl_JavaBridge_examples.html

Demonstrates basic usage of SqlHandle for executing a simple SQL query.

```FGL
MAIN
  DEFINE sc AS SQLCONNECTION
  DEFINE sh AS base.SqlHandle
  DEFINE rc AS INTEGER

  LET sc = base.connect("demodb")
  IF sc.isError() THEN
    MESSAGE "Connection error: " || sc.getErrorText() ESCAPE
    RETURN
  END IF

  LET sh = base.SqlHandle.create(sc)
  LET rc = sh.execute("CREATE TABLE my_table (id INT, name CHAR(20))")
  IF rc < 0 THEN
    MESSAGE "Error creating table: " || sh.getErrorText() ESCAPE
  ELSE
    MESSAGE "Table created successfully."
  END IF

  LET rc = sh.execute("DROP TABLE my_table")
  IF rc < 0 THEN
    MESSAGE "Error dropping table: " || sh.getErrorText() ESCAPE
  ELSE
    MESSAGE "Table dropped successfully."
  END IF

  LET sh.close()
  LET sc.close()
END MAIN
```

--------------------------------

### Creating a Directory using os.Path.mkDir

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/index.html?q=%2Fonline_documentation%2Ffjs-fgl-manual-html%2Ffgl-topics%2Fc_fgl_Migrate_to_200_dbi_informix.html

Demonstrates how to create a new directory at the specified path using os.Path.mkDir().

```esql
DEFINE new_dir_path VARCHAR(255);

-- Specify the path for the new directory
LET new_dir_path = "/tmp/my_new_directory"; -- Replace with a desired path

-- Attempt to create the directory
IF os.Path.mkDir(new_dir_path) = 0 THEN
    DISPLAY "Directory created successfully: ", new_dir_path;
ELSE
    -- Check if the directory already exists or describe other errors
    IF os.Path.exists(new_dir_path) THEN
        DISPLAY "Directory already exists: ", new_dir_path;
    ELSE
        DEFINE error_msg VARCHAR(255);
        LET error_msg = os.Path.describeLastError();
        DISPLAY "Failed to create directory. Error: ", error_msg;
    END IF;
END IF;

-- To create parent directories if they don't exist, you might need to call mkDir recursively or use a different function if available.
```

--------------------------------

### Get Next Sibling Element Example

Source: https://4js.com/online_documentation/fjs-fgl-manual-html/index.html?q=%2Fonline_documentation%2Ffjs-fgl-manual-html%2Ffgl-topics%2Fc_gws_XmlSignature_createReference.html

Example of getting the next sibling that is an element.

```javascript
var doc = new xml.DomDocument();
var parent = doc.createElement("parent");
doc.appendChild(parent);
var sibling1 = doc.createElement("sibling1");
parent.appendChild(sibling1);
var sibling2 = doc.createElement("sibling2");
parent.appendChild(sibling2);
var nextSiblingElement = sibling1.getNextSiblingElement();
console.log("Next sibling element: " + nextSiblingElement.getNodeName());
```