Hashtable DataFlex Reference Documentation
Hashtable
Current Version: 11.0.0
Represents a collection of key/value pairs that are stored in a hash table.
Note: This class was added in Chilkat v9.5.0.51
Object Creation
// (Dataflex programs use the 32-bit Chilkat ActiveX) Handle hoHashtable
Get Create(RefClass(cComChilkatHashtable)) to hoHashtable
Properties
Count
The number of items (strings/integers) contained in the hash table.
topDebugLogFilePath
Procedure Set ComDebugLogFilePath String value
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.
LastBinaryResult
This property is mainly used in SQL Server stored procedures to retrieve binary data from the last method call that returned binary data. It is only accessible if Chilkat.Global.KeepBinaryResult is set to True. This feature allows for the retrieval of large varbinary results in an SQL Server environment, which has restrictions on returning large data via method calls, though temp tables can handle binary properties.
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
Procedure Set ComLastMethodSuccess Boolean value
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.
LastStringResult
In SQL Server stored procedures, this property holds the string return value of the most recent method call that returns a string. It is accessible only when Chilkat.Global.KeepStringResult is set to TRUE. SQL Server has limitations on string lengths returned from methods and properties, but temp tables can be used to access large strings.
LastStringResultLen
The length, in characters, of the string contained in the LastStringResult property.
topVerboseLogging
Procedure Set ComVerboseLogging Boolean value
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
AddFromXmlSb
Adds to the hash table from XML previously created by calling ToXmlSb.
Returns True for success, False for failure.
AddInt
Adds or replaces an entry with the given key and integer value to the hash table. Returns True if a new hash entry was added or replaced. Returns False if an out-of-memory condition occurred.
Returns True for success, False for failure.
topAddQueryParams
Adds URL query parameters into the hashtable. The queryParams has the form: "field1=value1&field2=value2&field3=value3...". It is assumed that the values are URL encoded, and this method automatically URL decodes the values prior to inserting into the hashtable.
Returns True for success, False for failure.
AddStr
Adds or replaces an entry with the given key and string value to the hash table. Returns True if a new hash entry was added or replaced. Returns False if an out-of-memory condition occurred.
Returns True for success, False for failure.
topClear
Removes all elements from the Hashtable.
topClearWithNewCapacity
Removes all elements from the Hashtable and re-sizes with the specified capacity.
The capacity is the number of buckets in the hash table. In the case of a "hash collision", a single bucket stores multiple entries, which must be searched sequentially. One rule of thumb is to set the capacity to twice the number of expected items to be hashed. It's also preferable to set the capacity to a prime number. (The 1st 10,000 prime numbers are listed here: https://primes.utm.edu/lists/small/10000.txt )
The initial default capacity of the hash table is 521.
Returns True for success, False for failure.
topContains
Determines if a given key is contained within the hash table. Returns True if the key exists, otherwise returns False.
ContainsIntKey
Determines if a given key is contained within the hash table. Returns True if the key exists, otherwise returns False.
GetKeys
Appends the complete set of hashtable key strings to strTable.
Returns True for success, False for failure.
LookupInt
Returns the integer value associated with the specified key. If the key is not in the hash table, the return value is 0.
topLookupStr
Remove
Removes the entry with the specified key from the hash table. Returns True if the key existed and was removed. Returns False if the key did not already exist.
ToQueryString
Serializes the hash table to a query string such as key1=value1&key2=value2&key3=value3 where each value is URL encoded.
Returns null on failure
ToXmlSb
Serializes the hash table to XML format. The XML is appended to sbXml.
Returns True for success, False for failure.