I would like to trigger a method of an object by using BINDEVENT(), but the method may not exist. Thus, I want to check if the method is defined before issuing BINDEVENT().
For example, in the following code snippet, if oHandler.myresize() does not exist, the error will be triggered at the line of BINDEVENT().
PUBLIC oHandler
oHandler=NEWOBJECT("myhandler")
DO (_browser)
BINDEVENT(_SCREEN,"Resize",oHandler,"myresize")
DEFINE CLASS myhandler AS Session
PROCEDURE myresize
IF ISNULL(_obrowser) THEN
UNBINDEVENTS(THIS)
ELSE
_obrowser.left = _SCREEN.Width - _obrowser.width
ENDIF
RETURN
ENDDEFINE
Thus, I want to check the method myresize() exists or not.
Is there any language function for this purpose? It is very similar to a php function function_exits() or method_exists().
PEMSTATUS( VariableNameRepresentingTheObject, "MethodOrPropertyLookingFor", 5 )
returns true or false if exists on the given object.
Related
In WebhookScript, I can store a function in a variable with:
sub = function(a, b) {
return a - b
}
I'd like to store a function in a Global Variable so that I can use it in multiple Custom Actions. But if I've saved the above function as $sub$ then
sub2 = var('$sub$')
subX = sub(1,2)
causes an error:
Trying to invoke a non-function 'string' # line...
And
function subX(a,b){
var('$sub$')
}
when sub only contains return a - b, doesn't work either.
Obviously I need to convert the string to a function but I'm not sure whether that's possible.
I know this is a bit of an obscure language but if anyone knows how this can be done in similar languages like JavaScript and PHP, I'm happy to test out any guesses...
The solution here is to remove the function section and just enter the script, which inherits the execution scope so if my global variable $script$ is:
return 'hello ' + a
Then I can execute the function with:
a = 'world'
value = exec(var('$script$'))
echo(value)
(credit to Webhook.Site's support team for explaining this)
Using the example from the Spring docs, I'm trying to return a value from a mySQL function. I keep getting the error Can't set IN parameter for return value of stored function call;.
I created a mySQL function that works fine (ran in MySQL Workbench). I've written a SimpleJdbcCall statement, set up the parameters as per Spring docs example but consistently get this error. If I turn the function into a procedure, the code works, I just have to retrieve the return value from the result set.
I used https://docs.spring.io/spring/docs/3.0.0.M3/reference/html/ch13s05.html, section 13.5.8 as reference.
CREATE FUNCTION `ScenarioRegistration`(
environment VARCHAR(45),
username VARCHAR(15),
scenario_name VARCHAR(45)) RETURNS int(11)
A couple of SELECT statements followed by an INSERT then
RETURN scenario_id; // The inserted id
Java code:
SimpleJdbcCall simpleJdbcCall = new SimpleJdbcCall(getJdbcTemplate())
.withFunctionName("ScenarioRegistration")
.withoutProcedureColumnMetaDataAccess();
simpleJdbcCall.addDeclaredParameter(new SqlParameter("environment"
,Types.VARCHAR));
simpleJdbcCall.addDeclaredParameter(new SqlParameter("username"
,Types.VARCHAR));
simpleJdbcCall.addDeclaredParameter(new SqlParameter("scenario_name"
,Types.VARCHAR));
SqlParameterSource parameters = new MapSqlParameterSource()
.addValue("environment", environment)
.addValue("username", username)
.addValue("scenario_name", scenario);
simpleJdbcCall.setReturnValueRequired(true);
Integer scenario_id = simpleJdbcCall.executeFunction(
Integer.class, parameters);
All I want the routine to do is give me back the id of the newly inserted scenario.
What I get is:
SQL [{? = call scenarioregistration(?, ?)}]; Can't set IN parameter for return value of stored function call.
I find it interesting that it's taken my THREE input values and changed them to an output and TWO input values.
Anyone enlighten me as to the problem and how to fix it?
Thanks,
Steven.
I would refer to the latest docs here for your answer. It appears Spring is trying to infer the output because you didn't explicity specify one.
Per the docs above there are two valid approaches on calling the desired function with the SimpleJdbcCall:
Inferred Parameters
Because you've specified withoutProcedureColumnMetaDataAccess, Spring isn't going to look and see what the ins/outs are to your function. If you want it easy, just don't specify that and you should be able to do:
SqlParameterSource parameters = new MapSqlParameterSource()
.addValue("environment", environment)
.addValue("username", username)
.addValue("scenario_name", scenario);
Integer scenarioId = new SimpleJdbcCall(getJdbcTemplate())
.withFunctionName("ScenarioRegistration")
.executeFunction(Integer.class, parameters);
Explicit Parameters
If you want to keep withoutProcedureColumnMetaDataAccess turned off for whatever reason, you can do:
Integer scenarioId = new SimpleJdbcCall(getJdbcTemplate)
.withFunctionName("ScenarioRegistration")
.withoutProcedureColumnMetaDataAccess()
.useInParameterNames("environment", "username", "scenario_name")
.declareParameters(
new SqlOutParameter("scenario_id", Types.NUMERIC),
new SqlParameter("environment", Types.VARCHAR),
new SqlParameter("username", Types.VARCHAR),
new SqlParameter("scenario_name", Types.VARCHAR)
).executeFunction(Integer.class, parameters);
Note: It appears that order is critical in this example. The output parameter should be declared first, and the subsequent named IN parameters come last. That is, the order of the parameters ? are ordinal in [{? = call scenarioregistration(?, ?, ?)}])
Alternative NamedParameterJdbcTemplate Solution
Another way to invoke your function is via an actual JDBC call. This could hypothetically save you the grief of using the fine tuning of the SimpleJdbcCall.
Integer scenarioId = namedParameterJdbcTemplate.queryForObject(
"SELECT ScenarioRegistration(:environment, :username, :scenario_name)",
parameters,
Integer.class);
I write this code, but its not working, it gives this error
Call to a member function commit() on a non-object
Hear is my code
$datasource = $this->Arrear->getDataSource();
$datasource->begin();
if($this->Customar->saveField("total_bake",$amount) && $this->Arrear->save()){
$dataSource->commit();
return $this->redirect(array('action'=>'index'));
}else{
$dataSource->rollback();
$this->Session->setFlash('Data insert Failed','failure');
}
Variables in php(and hence in cakephp as well) are case-sensitive
http://php.net/manual/en/language.variables.basics.php
you have in your first line
$datasource = $this->Arrear->getDataSource();
but you are committing like
$dataSource->commit();
you have the data source assigned to $datasource, but not to $dataSource. The last variable even is not defined, that is why it is showing that error. So, you have to be sure you are using exactly the same variable (with same capitalization) in all places.
As a beginner in Lua, I am sorry if the answer on this is easy.
I was trying to call a function within a code, yet after 2 hours of searching I couldn't find the wanted results. (Maybe I use the wrong search query's?)
Example code
function Test123 ()
SayTest = True
if SayTest = True then
-- This Is where I want to call the function name Test123,
-- yet I can't seem to succeed in this since it is just
-- starting a new function
SystemNotice ( role, function)
end
end
This should be the result:
function Test123 ()
SayTest = True
if SayTest = True then
SystemNotice ( role, 'Test123')
end
end
If anyone can help me out, I would be thankful. If I am still being unclear, just tell me and I will try to describe it better. My excuses for my limited English.
In Lua functions are actually values. That means they do not really have a name, you can only assign them to a variable or table field, but since the value itself has no concept of its name, you can't retrieve it.
That said, with the debug library, you can do this:
function getfname()
return debug.traceback("", 2):match("in function '(.-)'");
end
function bar()
print(getfname())
end
bar(); -- prints bar
foo = bar;
foo() -- prints foo
knerf = {rab = bar};
knerf.rab() -- prints rab
Note that this only works with the default Lua error handler or one that returns the same or very similar output, however you can obviously modify the pattern to suit what you need.
Read this: I would not advise this solution for performance-intensive tasks. Both string matching and the traceback are not really suited for this. Also, obviously the debug library must be enabled so you can actually use the traceback function.
Your function declaration lacks anend.
function Test123 ()
end
Read the functions chapter from the Lua manual. Just for the record, your if will also need an end.
This is a construct that just goes against the Lua philosophy that functions are first class citizens:
a function is just another value, and as such it has no name.
A variable can be assigned a value, thus binding a function to a name.
But that name can change. or a function can have multiple names. Which one to pick?
A better solution would be creating an anonymous function with an upvalue (a closure) instead:
function genTest(name)
return function()
SayTest = true
if SayTest == true then
print ( 'role', name)
end
end
end
Test123 = genTest('Test123')
Test123()
foobar = Test123
foobar()
This creates a function with a bound local variable name (see PiL 6.1 ).
I would like to override a function to inspect its parameter values but the call it and pass the original parameters as normal. Is this possible? I am using Corona SDK by www.coronalabs.com
My code at present, which does not work, is:
-- getting a refrence to the original function so i can replace it with my overriding function
local newcircle = display.newCircle
-- my override
display.newCircle = function(...)
-- attempt to pass the parameters to this function on to the real function
local t = {...}
newcircle(unpack(t))
end
-- calling the overridden function as if it were normal
display.newCircle( display.newGroup(), "image.png" )
In your new display.newCircle implementation, you are using the undefined t table, and the deprecated arg automatic table.
Try this :
-- my override
display.newCircle = function(...)
local t = {...} -- you need to collect arguments to a table
-- dumb use of override
print(t[1])
-- attempt to pass the parameters to this function on to the real function
newcircle(unpack(t))
end