Does IntelliJ IDEA for Java have a refactor function that can automatically move a variable definition from within a block to outside a block and refactor the definition inside the block to be a reference.
In short, turn this:
try {
IndexResponse indexResponse = elkService.post(pipelineModel);
}
Into this:
IndexResponse indexResponse = null;
try {
indexResponse = elkService.post(pipelineModel);
}
I find myself doing this quite frequently. The "surround by" refactors are smart about this in that if do NOT yet have the surrounding element (try/catch, if/then, etc.) and the code you want to surround defines variables that are used outside the surround-bound code, it will define the variable outside the block.
What I'm trying to do is refactor code where I INTRODUCE a reference outside an already-existing block.
Not the end of the world, to do this manually, but I was wondering if such a thing exists and/or if others wished for it.
Since IntelliJ IDEA 2021.3 (EAP builds are already available) it's possible just to complete the variable outside of try block to bring it into the scope:
try {
IndexResponse indexResponse = elkService.post(pipelineModel);
}
catch(Exception exception) {}
inde|
Just start typing the variable name, then invoke the completion explicitly (with Ctrl+Space), and it will be brought into the scope automatically:
IndexResponse indexResponse = null;
try {
indexResponse = elkService.post(pipelineModel);
} catch (Exception exception) {
}
indexResponse
Disclosure: I'm IntelliJ IDEA developer responsible for implementation of this feature.
What I do is I just reference the variable outside of the block. This will of course be highlighted as an error. I can then type Alt+Enter on the error and invoke the Bring 'X x' into scope quick-fix, which will move the variable definition, but leave the assignment.
Related
I don't know if vue recognize the syntax below:
if(var error = errors.description){
location.href = "/redirect?topic="+error;
}
The code above returns a compilation error:
ERROR in ./resources/js/forms/Signup.vue?vue&type=script&lang=js& (./node_modules/babel-loader/lib??ref--4-0!./node_modules/vue-loader/lib??vue-loader-options!./resources/js/forms/Signup.vue?vue&type=script&lang=js&)
Someone knows how to assign a variable inside the if else condition?
This is rather a JavaScript syntax issue than Vue. While I highly recommend not assigning within a conditional, you can do so only by either declaring the variable earlier or not explicitly declaring it at all, i.e. by removing the var above.
Here's an example with your above code:
if(error = errors.description){
location.href = "/redirect?topic="+error;
}
To be clear, it is highly recommended not to do the above, or at the very least declare var error earlier so that you don't accidentally modify a global variable, like so:
let error;
if(error = errors.description){
location.href = "/redirect?topic="+error;
}
Of course the most explicit and safe solution to avoid confusion about the assignment is to simply do it earlier:
let error = errors.description;
if (error) {
location.href = "/redirect?topic="+error;
}
There has been some discussion about whether assignment within conditionals is good practice. However, on a completely separate note it is widely agreed that assigning variables that haven't been declared with var, let, or const is dangerous as you could accidentally modify variables of higher scope.
I'm new to Kotlin and I'm trying to do a simple task - create and write to a file. For some reason, using use() with a block function on printWriter() doesn't actually write.
File("test2.txt").printWriter().use { out ->
{
println("hmmm")
out.println("what's up")
log.info { "finished writing" }
}
}
In fact, the block function doesn't seem to be called at all - both "hmmm" and "finished writing" never show up, although the file itself is created (but is totally empty).
The much simpler writeText() works just fine - the file is created and the given text is written to the file.
File("test3.txt").writeText("testing")
What am I doing wrong in my use() version?
Edit: it seems to be a syntax issue with my block function. Looks like I have an extra pair of brackets? Would love a brief explanation as to why it makes it not work.
Edit 2: I think I understand now. The way I wrote it, I was essentially returning the block function itself rather than running through it.
So the problem was that the way I was writing the block function caused it to just return the inner block function, and not actually call it.
Here are two ways that work:
File("test2.txt").printWriter().use {
println("hmmm")
it.println("what's up")
log.info { "finished writing!" }
}
File("test2.txt").printWriter().use(fun(out) {
println("hmmm")
out.println("what's up")
log.info { "finished writing!" }
})
Although, for my purposes writeText() actually works just fine and is much shorter haha.
I want to create a Developer Variable to the workspace in Blockly, but I cannot find the necessary function/method.
I do not want to create the variable over a button. The variable should be included even if there is no block in the workspace.
With these two functions I can get the already created variables:
var variables = workspace.getAllVariables();
var dev_var = Blockly.Variables.allDeveloperVariables(workspace);
But what is the setting function?
Developer variables are variables that will never be visible to the user, but will exist in the generated code. If that's what you're looking for: there's no API for it, but here are some things you can do.
If you want to reserve the name so that users can't accidentally override your variable, call yourGenerator.addReservedWords('var1,var2,...'). You can initialize the variable in your wrapper code.
If you really want Blockly to both reserve and declare the variable for you, you could override the init function on your generator.
On the other hand, if what you want is a user-visible variable that always shows up in the toolbox, without the user creating it, you should call yourWorkspace.createVariable('variable_name').
The unit test blocks all assume that the variable unittestResults exists and can be written to. To indicate this, the block definition includes the function getDeveloperVars, which returns an array of strings. Each string is a variable name.Follow this issue in gtihub
Blockly.Blocks['unittest_fail'] = {
// Always assert an error.
init: function() {
this.setColour(65);
this.setPreviousStatement(true);
this.setNextStatement(true);
this.appendDummyInput()
.appendField(new Blockly.FieldTextInput('test name'), 'MESSAGE')
.appendField('fail');
this.setTooltip('Records an error.');
},
getDeveloperVars: function() {
return ['unittestResults'];
}
};
LINK : https://github.com/google/blockly/issues/1535
Q (tldr;): How do I use the JavaScanner in android-lint to check if a particular function call with a specific string as a parameter has been surrounded by a try/catch block.
Details: I have completed the android-lint tutorials on the official site and have gone through the source of the existing lint-checks. However, I can't seem to grasp the workflow for this AST-based parsing of JavaScanner. What I'm trying to achieve is to catch a function that sets a specific property and surround it with a try/catch block. For example:
MyPropertySettings.set("SOME_PROPERTY", "SOME_VAL");
should not trigger the lint rule but:
MyPropertySettings.set("SOME_SENSITIVE_PROPERTY", "SOME_VAL");
should because it's not surrounded by a try/catch block with SetPropertyException. I don't want to introduce the try/catch to the function itself because it only throws the exception in extremely rare cases (and the internals of the function are based on some reflection mojo).
For this question, even a workflow/hint would be fine. If I can get the first few steps, I might be able to grasp it better.
Update:
After some more study, I have found that I need to set the set function above in getApplicableMethodNames() and then, somehow read the property of that function to decide if the check applies. That part should be easy.
Surrounding try/catch would be more difficult and I gather I would need to do some "flow analysis". How is the question now.
Well, along with the getApplicableMethodNames() method, you need to override the visitMethod() function. You will get the MethodInvocationNode. Just fetch the arguments passed in the invocation using the node.astArguments() function. This returns a list of arguments that you can iterate through using a StrictListAccessor. Check the arguments passed and if it matches your criterion, run a loop and keep calculating the parent node of the invocation node till a try node is found. If it is a try node, then you can get a list of catches using node.astCatches(). Scan the list and find the appropriate exception. If not found, then report.
You can code like this:
check if it is surrounded by try/catch:
#Override
public void visitMethod(JavaContext context, AstVisitor visitor, MethodInvocation node) {
// check the specified class that invoke the method
JavaParser.ResolvedMethod method = (JavaParser.ResolvedMethod) context.resolve(node);
JavaParser.ResolvedClass clzz = method.getContainingClass();
boolean isSubClass = false;
// sSupportSuperType = {"class name"};
for (int i = 0; i < sSupportSuperType.length; i++) {
if (clzz.isSubclassOf(sSupportSuperType[i], false)) {
isSubClass = true;
break;
}
}
if (!isSubClass) return;
// check if surrounded by try/catch
Node parent = node;
while (true) {
Try tryCatch = context.getParentOfType(parent, Try.class);
if (tryCatch == null) {
break;
} else {
for (Catch aCatch : tryCatch.astCatches()) {
TypeReference catchType = aCatch.astExceptionDeclaration().astTypeReference();
}
parent = tryCatch;
}
}
// get the arguments string
String str = node.astArguments().first().toString();
if (!str.startsWith("\"SOME_PROPERTY\"")) {
context.report(ISSUE, node, context.getLocation(node), "message");
}
}
before this you have to define the specific method by override:
#Override
public List<String> getApplicableMethodNames() {
return Collections.singletonList("set");
}
I'm doing an experiment with wxWebConnect test application, incorporating the xpcom tutorial at "http://nerdlife.net/building-a-c-xpcom-component-in-windows/"
I adapt MyComponent class as necessary to compile together with testapp.exe (not as separate dll), and on MyApp::OnInit I have the following lines:
ns_smartptr<nsIComponentRegistrar> comp_reg;
res = NS_GetComponentRegistrar(&comp_reg.p);
if (NS_FAILED(res))
return false;
ns_smartptr<nsIFactory> prompt_factory;
CreateMyComponentFactory(&prompt_factory.p);
nsCID prompt_cid = MYCOMPONENT_CID;
res = comp_reg->RegisterFactory(prompt_cid,
"MyComponent",
"#mozilla.org/mycomp;1",
prompt_factory);
Those lines are copied from GeckoEngine::Init(), using the same mechanism to register PromptService, etc. The code compiles well and testapp.exe is running as expected.
I put javascript test as below :
try {
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
const cid = "#mozilla.org/mycomp;1";
obj = Components.classes[cid].createInstance();
alert(typeof obj);
// bind the instance we just created to our interface
alert(Components.interfaces.nsIMyComponent);
obj = obj.QueryInterface(Components.interfaces.nsIMyComponent);
} catch (err) {
alert(err);
return;
}
and get the following exception:
Could not convert JavaScript argument arg 0 [nsISupport.QueryInterface]
The first alert says "object", so the line
Components.classes[cid].createInstance()
is returning the created instance.
The second alert says "undefined", so the interface nsIMyComponent is not recognized by XULRunner.
How to dynamically registering nsIMyComponent interface in wxWebConnect environment ?
Thx
I'm not sure what is happening here. The first thing I would check is that your component is scriptable (I assume it is, since the demo you copy from is). The next thing I would check is whether you can instantiate other, standard XULRunner components and get their interface (try something like "alert('Components.interfaces.nsIFile');" - at least in my version of wxWebConnect this shows an alert box with string "nsIFile".
Also, I think it would be worth checking the Error Console to make sure there are no errors or warnings reported. A magic string to do that (in Javascript) is:
window.open('chrome://global/content/console.xul', '', 'chrome,dialog=no,toolbar,resizable');