Formats Lazarus Pascal Reference Documentation
Formats
Current Version: 11.7.0
Markdown version of this page for AI tools (v 11.7.0) · all AI docs
Chilkat.Formats
Versions 1–40, error-correction levels L/M/Q/H, automatic or explicit version and mask, numeric/alphanumeric/byte modes, ECI, structured append. Integer-pixel modules, px/mm/in/pt units with DPI, quiet zone, padding, rotation, colors with opacity, caption text, size limits with shrink-to-fit. Returned inline as base64 or SVG text, or written to files (numbered file sets for structured append). Optional module bit-matrix and reusable definition.
See the Barcode / QR Code Generation Overview
for the complete documentation with examples and sample images.
A collection of data-format operations, starting with barcode and QR code generation.
Chilkat.Formats is not string, number or date display formatting. It groups operations on
well-defined data formats behind a small number of JSON-driven methods, so the class can grow by adding a
method per format family without adding a public class for each feature. Introduced in v11.7.0 with the
barcode feature methods Barcode and QrCode.
QR Code generation
Precise rendering
PNG or SVG output
Measure and validate
measure reports exact geometry without rendering; validate checks a request; capabilities describes what the build supports.method(op, jsonIn, jsonOut). Requests are
checked strictly (unknown options are rejected, not ignored) and every failure has a stable error code with the
JSON Pointer of the offending member.
Create / Free
uses
Chilkat.Formats;
var
obj: TFormats;
begin
obj := TFormats.Create;
try
if not obj.IsValid then
raise Exception.Create('Failed to create a TFormats instance.');
// ... use obj ...
finally
obj.Free;
end;
end;
Allocates the underlying CkFormats object and returns a new TFormats instance. Simply adding Chilkat.Formats to the unit's uses clause is enough to locate and bind to the Chilkat shared library (DLL / .so / .dylib) at runtime — no separate load step is required. Check obj.IsValid after calling Create; it is False if the underlying library could not be found/loaded or the object could not be allocated (for example, when unlicensed).
Every TFormats created by calling Create should eventually be released by calling .Free (inherited from TObject). The destructor automatically disposes the underlying CkFormats handle. A native (unmanaged) memory leak occurs if the object is never freed.
Properties
DebugLogFilePath
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
LastErrorHtml
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastErrorText
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
LastErrorXml
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastMethodSuccess
Indicates the success or failure of the most recent method call: True means success, False means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
VerboseLogging
If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.
Version
Methods
Barcode
// jsonOut is a TJsonObject object.
function Barcode(const op: string;
jsonIn: TChilkatBase;
jsonOut: TChilkatBase): Boolean;
Runs one barcode operation and returns the result as JSON. op is the operation: "generate" (encode the payload, lay out the symbol and render a PNG or SVG), "measure" (encode and lay out only, reporting the exact geometry and whether the symbol fits), "validate" (examine a request's definition, capacity or layout) or "capabilities" (describe the symbologies, operations, formats and limits this build implements). jsonIn is the request: it names the symbology (currently "qr"), the payload (text or base64 binary) and optional encoding, render, output and limits groups. jsonOut is replaced with the response. Every response carries errors[] and warnings[]; a successful "generate" also returns symbols[] (the encoding actually selected), measurements[] (pixel geometry) and outputs[] (the image as base64 or SVG text, or the path of the file written).
Returns True when the operation completed successfully. Returns False when the request was rejected or execution failed; errors[0] then holds a stable code, the JSON Pointer path of the offending request member and a message.
The request and response vocabulary (payload types, QR version, error correction, mask, ECI, structured append, module size and physical units, quiet zone, rotation, colors, captions, PNG/SVG output, file writing, limits and error codes) is documented in full, with examples and sample images, at the links below.
Returns True for success, False for failure.
QrCode
// jsonOut is a TJsonObject object.
function QrCode(const op: string;
jsonIn: TChilkatBase;
jsonOut: TChilkatBase): Boolean;
The same as Barcode with the symbology defaulting to "qr", so the smallest request is { "payload": { "text": "..." } }. op is the operation ("generate", "measure", "validate" or "capabilities"), jsonIn the request and jsonOut the response. Identical requests to QrCode and Barcode produce identical results; a request naming a symbology outside the QR family is rejected.
Generates QR Code (Model 2) symbols in versions 1-40 with error-correction levels L, M, Q and H, automatic or explicit version and mask selection, numeric, alphanumeric and byte modes, optional ECI, and structured append of up to 16 symbols. Output is PNG or SVG, returned inline (base64 or SVG text) and/or written to files.
Returns True when the operation completed successfully, otherwise False with the reason in errors[0] of jsonOut (code, JSON Pointer path and message). See the links below for the complete documentation of every option, with examples and sample images.
Returns True for success, False for failure.