ABAP String Escaping: Quotes, XML, JSON, Special Characters

In SAP ABAP, “escaping” a string usually refers to handling special characters (such as quotes, backslashes, etc.) or ensuring that certain characters are interpreted correctly within strings or within specific contexts (like XML, JSON, or database queries).

1. Escaping Single Quotes in Strings

In ABAP, if you want to include single quotes (') inside a string, you need to escape them by doubling the single quote ('').

DATA: lv_string TYPE string.

lv_string = 'It''s a test'.
WRITE: lv_string.  " Output: It's a test

• Explanation: The '' escapes the single quote so that it is interpreted as part of the string.

2. Escaping Double Quotes in Strings

In ABAP, you don’t need to escape double quotes (") directly within strings, as they are typically used for comments, but if you want to use them, you can include them like this:

DATA: lv_string TYPE string.

lv_string = 'He said, "Hello ABAP!"'.
WRITE: lv_string.  " Output: He said, "Hello ABAP!"

• Explanation: Double quotes do not need escaping in ABAP string literals.

3. Escaping Backslashes (\)

To include a backslash (\) in an ABAP string, you need to escape it by using double backslashes (\\).

DATA: lv_string TYPE string.

lv_string = 'This is a backslash: \\'.
WRITE: lv_string.  " Output: This is a backslash: \

• Explanation: The first backslash is used as an escape character, so the second one appears in the output.

4. Handling Special Characters in XML/HTML (XML Escape)

If you need to escape special characters for XML or HTML content (like <, >, &, etc.), you can use the SCMS_XML_DECODE or SCMS_XML_ENCODE function modules.

Example: XML Encoding:

DATA: lv_string TYPE string,
      lv_encoded TYPE string.

lv_string = 'This is <ABAP> & "XML" example'.
CALL FUNCTION 'SCMS_XML_ENCODE'
  EXPORTING
    input  = lv_string
  IMPORTING
    output = lv_encoded.

WRITE: lv_encoded.  " Output: This is &lt;ABAP&gt; &amp; &quot;XML&quot; example

• Explanation: This encodes the special characters to their XML-safe equivalents.

Example: XML Decoding:

DATA: lv_string TYPE string,
      lv_decoded TYPE string.

lv_string = 'This is <ABAP> & "XML" example'.
CALL FUNCTION 'SCMS_XML_DECODE'
  EXPORTING
    input  = lv_string
  IMPORTING
    output = lv_decoded.

WRITE: lv_decoded.  " Output: This is <ABAP> & "XML" example

• Explanation: This decodes the XML entities back into their original characters.

5. JSON Escaping

If you’re working with JSON, you may need to escape special characters like quotes, backslashes, and newlines. ABAP provides built-in methods to handle these in more recent versions:

Example: Using IF_JSON for JSON Encoding:

DATA: lv_json TYPE string.

lv_json = `{"key": "value with "quotes" and backslash\\."}`.

WRITE: lv_json.

• Explanation: ABAP automatically handles the escaping when you use the IF_JSON interface for encoding JSON.

6. Escape Newline or Carriage Return

If you need to include newline characters or carriage returns (\n or \r), use the corresponding ABAP escape sequence:

DATA: lv_string TYPE string.

lv_string = 'This is a line. ' && cl_abap_char_utilities=>cr_lf && 'Next line.'.
WRITE: lv_string.

• Explanation: cl_abap_char_utilities=>cr_lf inserts a newline (\r\n) into the string.

Best Practices for Escaping

• Quotes: Use '' to escape single quotes.
• Backslashes: Use \\ to escape backslashes.
• XML/HTML: Use SCMS_XML_ENCODE and SCMS_XML_DECODE to handle special characters for XML/HTML.
• JSON: Use ABAP’s JSON utilities for proper encoding and escaping.
• Newline/Carriage Return: Use cl_abap_char_utilities=>cr_lf for line breaks.