Since nodejs >= 10 FunctionCallbackInfo::Callee has been deprecated (https://github.com/nodejs/nan/blob/master/CHANGELOG.md). I need to update a c++ code that uses v8, where the method name being called was used. How to get that now?
It is recommemded to use info.Data() instead. But I don't follow how to get the methods name from that. I guess it goes something like this:
void GetData(IN const Nan::FunctionCallbackInfo<v8::Value>& info)
{
v8::Local<v8::Function> data = v8::Local<v8::Function>::Cast(info.Data());
....
}
How do I get the methods name from data? From the documentation, looks like it cannot be done any longer (https://github.com/nodejs/nan/blob/master/doc/methods.md):
Note: FunctionCallbackInfo::Callee is removed in Node.js after 10.0.0 because it is was deprecated in V8. Consider using info.Data() to pass any information you need.
So, if no extra information is supplied, there is no way to get the name of the callee?
This did the trick:
v8::Local<v8::Function> out;
out = v8::Local<v8::Function>::Cast(info.Data());
v8::String::Utf8Value callee(out->GetName()->ToString());
Related
I'm working on a custom controller for a custom resource using kubebuilder (version 1.0.8). I have a scenario where I need to get a list of all the instances of my custom resource so I can sync up with an external database.
All the examples I've seen for kubernetes controllers use either client-go or just call the api server directly over http. However, kubebuilder has also given me this client.Client object to get and list resources. So I'm trying to use that.
After creating a client instance by using the passed in Manager instance (i.e. do mgr.GetClient()), I then tried to write some code to get the list of all the Environment resources I created.
func syncClusterWithDatabase(c client.Client, db *dynamodb.DynamoDB) {
// Sync environments
// Step 1 - read all the environments the cluster knows about
clusterEnvironments := &cdsv1alpha1.EnvironmentList{}
c.List(context.Background(), /* what do I put here? */, clusterEnvironments)
}
The example in the documentation for the List method shows:
c.List(context.Background, &result);
which doesn't even compile.
I saw a few method in the client package to limit the search to particular labels, or for a specific field with a specific value, but nothing to limit the result to a specific resource kind.
Is there a way to do this via the Client object? Should I do something else entirely?
So figured it out - the answer is to pass nil for the second parameter. The type of the output pointer determines which sort of resource it actually retrieves.
According to the latest documentation, the List method is defined as follows,
List(ctx context.Context, list ObjectList, opts ...ListOption) error
If the List method you are calling has the same definition as above, your code should compile. As it has variadic options to set the namespace and field match, the mandatory arguments are Context and objectList.
Ref: KubeBuilder Book
I am using a 3rd party library that invokes a Core Foundation function.
Since that lib has a bug, passing incorrect values to a CF function, I need to intercept that call to fix the passed values.
How do I hook into the CF function call so that I can look at the passed parameters, change them and then call the actual (original) function?
I have the impression I can get to the actual function with the CFBundleGetFunctionPointerForName, passing CFBundleGetMainBundle()as the first parameter and the name of the CF function as the second parameter.
In my particular case, that would be:
void *p = CFBundleGetFunctionPointerForName (CFBundleGetMainBundle(), "CFRunLoopTimerCreate");
But that returns NULL.
I also tried this:
void *p = CFBundleGetFunctionPointerForName (CFBundleGetBundleWithIdentifier("com.apple.Cocoa"), "CFRunLoopTimerCreate");
That returns a non-null value but it still does not appear to be a pointer I could change but rather the actual starting address of the function's code.
So, how do I get an address of a function pointer to an imported API function that I can save and then change to point to my intercepting function? Or how else could I hook into an imported function?
CFBundleGetFunctionPointerForName will just return the address of a function in a given bundle; this will never let you change the destination of calls to the function. If you really want to do something like that, please refer to Is it possible to hook API calls on Mac OS? Note that this is highly not recommended.
Good day!
I began writing my own basic JavaScript library for personal use and distribution a few days ago, but I am having trouble with one of the methods, specifically bind().
Within the method itself, this refers to the library, the object.
I went to Google and found function.call(), but it didn't work out the way I planned it--it just executed the function.
If you take a look at another method, each(), you'll see that it uses call() to pass values.
I also tried the following:
f.arguments[0]=this;
My console throws an error, saying it cannot read '0' of "undefined".
I would like to be able to pass this (referencing the library--NOT THE WINDOW) to use it in the event listener.
You can see it starting at line 195 of the JavaScript of this JSFiddle.
Here it is as well:
bind:function(e,f){
if(e.indexOf("on")==0){
e=e.replace("on","");
}
if(typeof f==='function'){
/*Right now, 'this' refers to the library
How can I pass the library to the upcoming eventListener?
*/
//f=f(this); doesn't work
//f.call(this); //doesn't work
//this.target refers to the HTMLElement Object itself, which we are adding the eventListener to
//the outcome I'm looking for is something like this:
/*$('h3').which(0).bind(function({
this.css("color:red");
});*/
//(which() defines which H3 element we're dealing with
//bind is to add an event listener
this.target.addEventListener(e,f,false)
}
return this;
},
Thank you so much for your help, contributors!
If, as per your comments, you don't want to use .bind(), rather than directly passing f to addEventListener() you could pass another function that in turn calls f with .call() or .apply():
if(typeof f==='function'){
var _this = this;
this.target.addEventListener(e,function(event){
f.call(_this, event);
},false)
}
Doing it this way also lets your library do any extra event admin, e.g., pre-processing on the event object to normalise properties that are different for different browsers.
So in this particular case you actually want to call JavaScript's built in bind method that all functions have.
f = f.bind(this);
f will be a new function with it's this argument set to whatever you passed into it.
Replace f=f(this); with f.apply(this);
Look at underscore code, here:
https://github.com/jashkenas/underscore/blob/master/underscore.js#L596
The question says it all I'd like to use CacheBuilder, but my values are pulled in asynchronously. This worked previously with MapMaker as the CacheLoader wasn't a requirement. Now I'd like to know if I can hack this up or if there are any non deprecated alternatives. Thank you.
I think the question you're trying to ask is "How can I use CacheBuilder without having to specify a CacheLoader?" If that's the case, then there will be support for this in Guava release 11.0. In the meantime a build() method on CacheLoader is already checked into trunk (as of this morning):
http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/cache/CacheBuilder.html
One method would be to make with generic parameters K and V as your desired outputs:
LoadingCache<K, ListenableFuture<V>> values = CacheBuilder.newBuilder()
.build(
new CacheLoader<K, ListenableFuture<V>>() {
public ListenableFuture<V> load(K key) {
/* Get your future */
}
});
Titanium SDK version: 1.6.
iPhone SDK version: 4.2
I am trying out the cache snippet found on the Appcelerator forum but I get an error: [ERROR] Script Error = Can't find variable: utils at cache.js (line 9).
I put this one (http://pastie.org/1541768) in a file called cache.js and implemented the code from this one (http://pastie.org/pastes/1541787) in the calling script, but I get the error.
What is wrong? I copied the code exactly.
Your problems is whilst the first pastie defines utils.httpcache. The variable utils is not defined outside of this function closure (because it is not defined anywhere in global namespace). As below shows.
(function() {
utils.httpcache = {
};
})();
To make it all work in this instance add the following code to the top of your cache.js file.
var utils = {};
This declares the utils variable in global namespace. Then when the function closure is executed below it will add utils.httpcache to the utils object.
The problem is actually not specific to Appcelerator and is just a simple JavaScript bug. Checkout Douglas Crockfords book, JavaScript the Good Parts. Reading it will literally make you a more awesome JavaScript developer.
You can't use utils.httpcache.getFromCache(url) until you add this to your code:
var utils = {};
That's because how the author created his function, it's called JavaScript module pattern and it's generally used to structure the code.
I seem to lose this value "value.httpCacheExpire = expireTime;" when the code does the "Titanium.App.Properties.setString(key,JSON.stringify(value));" so when I get it back using the getString method, there's no longer the "value.httpCacheExpire.
Anyone else have this issue? Am I missing something to get this working?