chilkat.JsonObject

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.

Specifies the character used to separate object-member names in Chilkat JSON paths. The default is .. Set it to / for Firebase-style paths. This property should contain exactly one character.

Controls whether emitted JSON is compact or pretty-printed. The default is true.

Controls line endings when pretty-printed JSON is emitted (EmitCompact = false). The default is true.

Enables automatic resolution of Chilkat secret specification strings for supported string-setting methods. The default is false. When enabled, a value beginning with !! can identify a credential stored in Windows Credential Manager or Apple Keychain instead of embedding the literal secret in application code.

Secret specification format: !![appName|]service[|domain]|username.

This feature applies to AddStringAt, AppendString, SetStringAt, SetStringOf, UpdateSb, and UpdateString.

Supplies the integer substituted for i when a JSON path contains an array index such as [i]. This is useful for loop-based navigation without constructing a new path string for every iteration.

Supplies the integer substituted for j when a JSON path contains [j]. It is commonly used with nested-array paths such as matrix[i][j].

Supplies the integer substituted for k when a JSON path contains [k]. It can be combined with I and J for deeper nested-array traversal.

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.

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.

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.

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.

If true, member names are converted to lowercase while JSON is loaded by Load, LoadBd, LoadSb, or LoadFile. The default is false.

Specifies a path prefix automatically prepended to JSON paths passed to path-based methods such as StringOf, ObjectOf, UpdateString, SetBoolOf, and SizeOfArray. The default is the empty string.

Returns the number of direct name/value members in this JSON object. Nested members inside child objects are not included.

When Strict is true, the Load methods first check that the data is well-formed JSON. If it is not, the load fails and the contents of this JsonObject are left unchanged. The default is false.

This applies to Load, LoadSb, LoadBd, LoadFile and LoadPredefined.

Chilkat's JSON parser is deliberately tolerant. By default it can accept text that is not well-formed, succeed, and leave an empty or partially populated document. That is convenient when the goal is a best-effort parse of imperfect input, but it is the wrong behavior when a silently missing member changes what the application does. A single missing comma, for example, can cause the members after it to be dropped while the load still reports success.

Set Strict to true for JSON carrying configuration, credentials, or security parameters, where a member that quietly failed to load would be acted on as though it had never been specified.

Provides a catch-all string for uncommon, implementation-specific options. The default is the empty string and it should normally remain empty.

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 of the component/library, such as "10.1.0"

Inserts a new JSON array member named name at the zero-based member position index. The new array is empty.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Inserts a new JSON array member named name at the zero-based member position index. The array value is copied from jarr; subsequent changes to the source array do not modify the inserted copy.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Inserts a new JSON boolean member named name at the zero-based member position index. The value is taken from value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Inserts a new JSON number member named name at the zero-based member position index. The integer value is emitted as a JSON number, not as a quoted string.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Inserts a new JSON null member named name at the zero-based member position index.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Inserts a new JSON number member named name at the zero-based member position index. The numericStr argument supplies the exact JSON numeric text to store.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Inserts a new JSON object member named name at the zero-based member position index. The new object is empty.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Inserts a new JSON object member named name at the zero-based member position index. The object value is copied from jsonObj; the inserted value is independent of the source.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Inserts a new JSON string member named name at the zero-based member position index. The value is stored as a JSON string and is escaped as needed when emitted.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends a new JSON array member named name to this object. The newly appended array is empty and the returned JsonArray references that array in this document, so changes made through it modify the same JSON tree.

Returns a new object, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead. The returned object is independent of this one.

Appends a new JSON array member named name to this object. A new empty array is created and jarr is updated to reference it. The method returns true on success.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends a new JSON array member named name to this object. The array is copied from jarr, so the appended array is independent of the source array.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends a new JSON boolean member named name to this object. The value is taken from value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends a new JSON number member named name to this object. The integer value is stored as a JSON number.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends a new JSON object member named name to this object. The newly appended object is empty and the returned JsonObject references that object in this document.

Returns a new object, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead. The returned object is independent of this one.

Appends a new JSON object member named name to this object. A new empty object is created and jsonObj is updated to reference it. The method returns true on success.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends a new JSON object member named name to this object. The object is copied from jsonObj, so the appended object is independent of the source object.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends a new JSON string member named name to this object. The value is JSON-escaped as needed when emitted.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Appends a new JSON array member named name to this object. The array is populated with the strings contained in values.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns the JSON array stored in the member at zero-based position index. The returned JsonArray references the existing array in the same document; it is not a detached copy.

Returns a new object, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead. The returned object is independent of this one.

Updates jarr to reference the JSON array stored at zero-based member position index and returns true on success.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns the JSON array at jsonPath. The returned JsonArray references the existing array in the same document, so modifications through it are reflected in the parent JSON.

Returns a new object, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead. The returned object is independent of this one.

Updates jarr to reference the JSON array at jsonPath and returns true on success.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns the boolean value of the member at zero-based position index.

Returns true or false: an answer, not a success flag.

Returns the boolean value at jsonPath. The path is evaluated relative to this JsonObject, after applying PathPrefix if one is set.

Returns true or false: an answer, not a success flag.

Reads the string value at jsonPath, decodes it using encoding (for example, base64 or hex), and appends the resulting bytes to bd.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Removes all members from this JSON object, leaving an empty object equivalent to {}.

Updates jsonObj so that it references the same JSON object as the caller. No JSON data is copied.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Parses the date/time value at jsonPath and loads the result into dt. Recognized forms include ISO 8601 timestamps (for example, 2009-11-04T19:55:41Z), RFC 822-style date/time strings, and Unix timestamp integers.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Deletes the direct member named name from this JSON object.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Deletes the member at zero-based position index. Members after the deleted position shift toward the beginning.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Deletes every object record in the array at arrayPath whose value at relative path relpath equals or wildcard-matches value. The caseSensitive argument controls matching. Returns the number of records deleted.

Parses the date/time value at jsonPath into dt. If bLocal is true, the destination receives local date/time fields; otherwise it receives UTC/GMT fields. Recognized inputs include ISO 8601 timestamps, RFC 822-style date/time strings, and Unix timestamp integers.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Serializes the JSON document rooted at this object and returns the JSON text. Formatting is controlled by EmitCompact and, for pretty output, EmitCrLf.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Serializes this JSON and appends the resulting bytes to bd.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Serializes this JSON and appends the resulting text to sb. Formatting follows EmitCompact and EmitCrLf.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Serializes the JSON after substituting variables from subs into template strings. A placeholder such as {$name} is replaced by the corresponding hashtable value. Prefixing the variable name with i., as in {$i.count}, emits the substituted value as a JSON integer instead of a quoted string.

If omitEmpty is true, members whose substituted result is an empty string or empty array are omitted from the emitted JSON.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Recursively searches this JSON subtree for the first JSON object containing a direct member named name. Returns that object, or nil if no matching object is found.

Returns a new object, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead. The returned object is independent of this one.

Recursively searches this JSON subtree for the first object containing a direct member named name. On success, jsonObj is updated to reference the matching object and the method returns true.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Searches the JSON array at arrayPath for the first object whose value at relative path relPath equals or wildcard-matches value. The caseSensitive argument controls string comparison. Returns the matching record object.

Returns a new object, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead. The returned object is independent of this one.

Searches the JSON array at arrayPath using the same matching rules as FindRecord. On success, jsonObj is updated to reference the first matching record and the method returns true.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Searches the JSON array at arrayPath for the first record whose relPath value equals or wildcard-matches value, then returns the value at retRelPath from that same record as a string.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Applies a Firebase Realtime Database event to this JSON object. name should be put or patch, and data should contain event JSON such as {"path":"/","data":{"a":1,"b":2}}.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Applies Firebase-style patch semantics at jsonPath. jsonData must contain a JSON object; each key in that object updates or adds the corresponding key at the target path.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Applies Firebase-style put semantics at jsonPath, replacing or inserting the value at that path. value is JSON text and may represent an object, array, number, boolean, null, or a quoted JSON string.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns a JsonObject reference to the root object of the JSON document containing this object. This can be called from any nested object reference.

Returns a new object, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead. The returned object is independent of this one.

Updates docRoot to reference the root object of the JSON document containing the caller and returns true on success.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns true if a value exists at jsonPath; otherwise returns false.

Returns true or false: an answer, not a success flag.

Returns the zero-based position of the direct member named name, or -1 if that member name is not found.

Returns the integer value of the member at zero-based position index.

Returns the integer value at jsonPath. The path is evaluated relative to this JsonObject, after applying PathPrefix if one is set.

Returns true if the member at zero-based position index has the JSON value null; otherwise returns false.

Returns true or false: an answer, not a success flag.

Returns true if the value at jsonPath is the JSON literal null; otherwise returns false.

Returns true or false: an answer, not a success flag.

Returns an integer identifying the JSON type of the value at jsonPath. Returns -1 if no member exists at that path.

Parses the JSON text in json and loads the parsed data into this object for DOM-style access and modification.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Parses JSON from the bytes contained in bd and loads it into this object.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Reads JSON text from the file at path, parses it, and loads the result into this object.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Loads this object from the predefined JSON document identified by name. Predefined documents are created with Predefine.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Parses JSON from the current contents of sb and loads it into this object.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Copies this JSON object into json. The destination receives an independent JSON copy rather than another reference to the same underlying object.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Moves the direct member at zero-based position fromIndex to toIndex. Use toIndex = 0 to move it first or -1 to move it last.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns the name of the member at zero-based position index. Use this with Size and TypeAt to iterate through an object's direct members.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Creates a JSON array at path and loads that array from the JSON text in jArr. The supplied text should represent a JSON array.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Creates a JSON object at path and loads that object from the JSON text in jObj. The supplied text should represent a JSON object.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns the JSON object stored in the member at zero-based position index. The returned JsonObject references the existing child object in the same document; changes made through it modify that document.

Returns a new object, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead. The returned object is independent of this one.

Updates jsonObj to reference the JSON object stored at zero-based member position index and returns true on success.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns the JSON object at jsonPath. The returned object is a live reference into the same JSON document, not a copy.

Returns a new object, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead. The returned object is independent of this one.

Updates jsonObj to reference the JSON object at jsonPath and returns true on success.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Stores this JSON document in Chilkat's internal global collection of predefined JSON documents under name. If the name already exists, the predefined value is replaced.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Renames the direct member oldName to newName. The member value and its position are otherwise unchanged.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Renames the member at zero-based position index to name. The member value is not changed.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the member at zero-based position index to a JSON boolean value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the value at jsonPath to a JSON boolean value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the member at zero-based position index to a JSON number value. The integer is emitted as a JSON number.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the value at jsonPath to an integer JSON number.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the member at zero-based position index to a JSON null value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the value at jsonPath to a JSON null value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the member at zero-based position index to a JSON number value. The value argument is the exact textual representation of the JSON number.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the value at jsonPath to a JSON number value. The value argument supplies the exact textual form of the JSON number.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the member at zero-based position index to a JSON string value. The string is escaped as required when JSON is emitted.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Sets the value at jsonPath to a JSON string value. The string is escaped as required when JSON is emitted.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns the number of elements in the JSON array at jsonPath. Returns -1 if the path does not resolve to an existing JSON array.

Sorts this object's direct members by member name. ascending selects ascending or descending order, and caseSensitive controls how names are compared.

Returns the string value of the member at zero-based position index.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns the value at jsonPath as text. For a JSON string, the string value is returned. Scalar non-string values such as numbers, booleans, and null are returned using their JSON textual representation.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns true if the textual value at jsonPath equals value according to the caseSensitive setting; otherwise returns false.

Returns true or false: an answer, not a success flag.

Retrieves the value at jsonPath as text and appends it to sb.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Swaps the positions of the direct members at zero-based indexes index1 and index2. Member names and values are unchanged.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Returns an integer identifying the JSON type of the member at zero-based position index. Returns -1 if no member exists at that index.

Returns the unsigned integer value at jsonPath.

Updates the value at jsonPath to a JSON string value, or creates the member and any missing path components as needed. The bytes in bd are first encoded according to encoding (for example, base64 or hex) and the encoded text is stored as the JSON string value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Updates the value at jsonPath to a JSON boolean value, or creates the member and any missing path components as needed.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Updates the value at jsonPath to a JSON number value, or creates the member and any missing path components as needed. The integer value is stored as a JSON number.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Creates or replaces the value at jsonPath with a new empty JSON array. Missing path components are created automatically as needed.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Creates or replaces the value at jsonPath with a new empty JSON object. Missing path components are created automatically as needed.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Updates the value at jsonPath to a JSON null value, or creates the member and any missing path components as needed.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Updates the value at jsonPath to a JSON number value, or creates the member and any missing path components as needed. The numericStr argument is stored as the exact textual representation of the JSON number.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Updates the value at jsonPath to a JSON string value, or creates the member and any missing path components as needed. The new string value is taken from the contents of sb.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Updates the value at jsonPath to a JSON string value, or creates the member and any missing path components as needed. The supplied string is JSON-escaped as needed.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Updates the value at jsonPath to a JSON number value, or creates the member and any missing path components as needed. The unsigned integer is stored as a JSON number.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

Serializes this JSON and writes it to the file at path. Output formatting follows EmitCompact and EmitCrLf.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.