EmbAJAXScriptedSpan Class Reference

A span element containing a custom javascript script, meant to creating custom dispays. More...

#include <EmbAJAXScriptedSpan.h>

Inheritance diagram for EmbAJAXScriptedSpan:

Collaboration diagram for EmbAJAXScriptedSpan:

Public Member Functions
	EmbAJAXScriptedSpan (const char *id, const char *script, char *rec_buffer=0, size_t rec_buffer_size=0)
void	print () const override
const char *	value (uint8_t which=EmbAJAXBase::Value) const override
const char *	valueProperty (uint8_t which=EmbAJAXBase::Value) const override
void	setValue (const char *value)
void	updateFromDriverArg (const char *argname) override
Public Member Functions inherited from EmbAJAXElement
	EmbAJAXElement (const char *id)
const char *	id () const
bool	sendUpdates (uint16_t since, bool first) override
virtual bool	valueNeedsEscaping (uint8_t which=EmbAJAXBase::Value) const
EmbAJAXElement *	toElement () override final
Public Member Functions inherited from EmbAJAXBase
void	setVisible (bool visible)
void	setEnabled (bool enabled)
virtual EmbAJAXElement *	findChild (const char *id) const

Additional Inherited Members
Public Types inherited from EmbAJAXBase
enum	Property {   Visibility , Enabledness , Value , FirstElementSpecificProperty ,   HTMLAllowed }
Static Public Member Functions inherited from EmbAJAXBase
static void	setDriver (EmbAJAXOutputDriverBase *driver)
Protected Member Functions inherited from EmbAJAXElement
void	setBasicProperty (uint8_t num, bool status) override
bool	basicProperty (uint8_t num) const
void	setChanged ()
bool	changed (uint16_t since)
void	printTextInput (size_t size, const char *value) const
Protected Member Functions inherited from EmbAJAXBase
void	printChildren (EmbAJAXBase **children, size_t num) const
bool	sendUpdates (EmbAJAXBase **children, size_t num, uint16_t since, bool first)
EmbAJAXElement *	findChild (EmbAJAXBase **children, size_t num, const char *id) const
void	printPage (EmbAJAXBase **children, size_t num, const char *_title, const char *_header, uint16_t _min_interval) const
void	handleRequest (EmbAJAXBase **children, size_t num, void(*change_callback)())
Protected Attributes inherited from EmbAJAXElement
byte	_flags
const char *	_id
Static Protected Attributes inherited from EmbAJAXBase
static EmbAJAXOutputDriverBase *	_driver
static char	itoa_buf [8]
constexpr static const char	null_string [1]

Detailed Description

A span element containing a custom javascript script, meant to creating custom dispays.

This class creates a element containing a custom script. The script to use is passed in the constructor. The span element itself is accessible using "this", inside the script.

The script may contain "this.receiveValue = function(value) { [...] };". This function will then be called, when the value is changed from the server.

If the scripted object allows the user to make changes, the script should call "this.sendValue(value);", when the value has changed. You will also have to set a large enough receive buffer in the constructor in this case!

Warning

This class is new, and its API may not be quite stable at the time of this writing. Feedback welcome.

Constructor & Destructor Documentation

EmbAJAXScriptedSpan()

EmbAJAXScriptedSpan::EmbAJAXScriptedSpan ( const char *  id, const char *  script, char *  rec_buffer = 0, size_t  rec_buffer_size = 0  )

inline

Constructor. See the class description for some detail on how to provide a script.

Parameters

id	unique id of the span
script	the script code. See the class description for details.
rec_buffer	if the script supplies values to the server (via this.sendValue(x); in the script), a receive buffer is needed hold that value. Pass a pointer to a suitably sized buffer.
rec_buffer_size	size of the rec_buffer.

Member Function Documentation

setValue()

void EmbAJAXScriptedSpan::setValue ( const char *  value )

inline

Send the given value to the client side script. Note that if you call this very often, the client will probably not see every value. It will only get to see the latest value that was set on each poll.

Further note that as of this writing, EmbAJAX does not check whether the value is actually changed, when you call this. You can avoid network overhead by making sure to call setValue(), only when something has actually changed. This may be changed in a future version of EmbAJAX.

For safety, the value string is always quoted when sending it to the client. This is not a problem as long as you are sending strings or plain numbers. To send more complex objects (such as an array, or even a function), your receiveValue() function should contain a call to eval().

Parameters

value

Note: The string is not copied, so don't make this a temporary.

updateFromDriverArg()

void EmbAJAXScriptedSpan::updateFromDriverArg ( const char *  argname )

inlineoverridevirtual

override this in your derived class to allow updates to be propagated from client to server (if wanted). The implementation need not call setChanged().

Reimplemented from EmbAJAXElement.

value()

const char* EmbAJAXScriptedSpan::value ( uint8_t  which = EmbAJAXBase::Value ) const

inlineoverridevirtual

const char representation of the current server side value. Must be implemented in derived class. This base class handles visibility and enabledness, only. Do call the base implementation for any "which" that is not handled in your derived class.

Reimplemented from EmbAJAXElement.

valueProperty()

const char* EmbAJAXScriptedSpan::valueProperty ( uint8_t  which = EmbAJAXBase::Value ) const

inlineoverridevirtual

The JS property that will have to be set on the client. Must be implemented in derived class. This base class handles visibility and enabledness, only. Do call the base implementation for any "which" that is not handled in your derived class.

Reimplemented from EmbAJAXElement.

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The documentation for this class was generated from the following file:

• EmbAJAXScriptedSpan.h