Tell UglifyJS to skip a particular area of code - minify

Is there a way to tell UglifyJS to skip a particular section of code, perhaps using comments like this:
// uglifyjs:skipStart
filter = function(item){ /* some crazy filter logic that will repeat 500,000 times */ }
// uglifyjs:skipEnd
My use case has to do with avoiding the minification of a function that will be inlined and parsed in a custom way for performance gain. Minification breaks the simplified parser.

Unfortunately, there is not a way to do this.

The Global Definitions of Uglify Compressor is a feature you can use in order to conditionally drop code.
global_defs: {
DEBUG: false
}
the compressor will assume that's a constant defintion and will discard code like this as being unreachable:
if (DEBUG) {
...
}
http://lisperator.net/uglifyjs/compress

Related

How to know which rules were applied during autoformatting using PhpStorm?

I am trying to figure what rules PhpStorm is using in my current file during autoformatting via "Reformat Code" so I can tweak it better. Is there way to view the rules that were applied?
A more concrete example:
I have a file with this code:
public function rules(): array {
return array_merge(parent::rules(), [
['foo', 'bar'],
];
}
that is converted into:
public function rules(): array {
return array_merge(parent::rules(),
[
['foo', 'bar'],
]
]
}
but I don't know which rule I have to tweak in order to not apply that change. I also want to be able to tell in other cases which ruleset caused which change during autoformat.
Is that possible and if so how?
In general, you can check that by selecting a code block and then Help | Find Action | Adjust code style settings.
But, please be aware that it is not all that precise, it can and does miss things. In your particular case, try playing around with Function/constructor call arguments and Array initializer in Wrapping and Braces.

Display value + text using jQuery

I am a total beginner. I have a form in HTML and am trying to calculate a specific value using jQuery. I want this value to be displayed in paragraph <p id="final"></p> under the submit button, but am actually not sure, why my code isn't working.
jQuery(document).on("ready", function() {
jQuery("final").hide();
jQuery("#form").submit(function(e){
e.preventDefault();
const data = jQuery(this).serializeArray();
/*
some calculations
*/
$('#final').html($('#final').html().replace('','result + " text"'));
jQuery("#final").show();
}
}
Do you have any idea, what could I be doing wrong??
You've got a several issues here.
Firstly, don't mix jQuery and $. If you're using the former, it's normally to avoid jQuery's alias, $, from conflicting with other code that might use $.
Secondly, you don't actually do any calculation (from what I can see in your code), so I'm not sure what you're wanting to output. I'll assume you're going to fill that in later.
Thirdly, jQuery('final').hide() is missing the # denoting you're targeting by element ID.
Fourthly, the line
$('#final').html($('#final').html().replace('','result + " text"'));
...doesn't quite do what you think it does. For one thing, it makes no reference to your data variable. And running replace() on an empty string doesn't make much sense.
All in all I'm guessing you want something like (note also how I cache the #final element - that's better for perforamnce):
jQuery(function() { //<-- another way to write a document-ready handler
let el = jQuery('#final');
el.hide();
jQuery("#form").submit(function(e){
e.preventDefault();
const data = jQuery(this).serializeArray();
let calc = 5+2; //<-- do what you need to here
el.html(calc).show();
}
}
Guessing result is your variable and your above code is your current status, you should fix the html replacement to something like (depending on your acutal usecase):
$('#final').html(result + " text"));

Returning functional HTML code through Angular JS filter

I'm trying to filter any text through angular to return a font-awesome icon. Instead It's just returning plain text. Anyone know a fix? Thanks!
.filter('textToIcon', function($sce) {
return function(text) {
if(text!==''){
return '<i class="fa fa-child"></i>';
}
}
This is "Strict Conceptual Escaping" (SCE) in action.
For more information on what it is and how it works, take a look at this answer.
In a few words, Angular tries to protect your users from untrusted content that could do bad things to them. If you know that the values are safe to be interpreted as HTML, there are two approaches you can take:
Import ngSanitize (it is available as a separate module) and add it as a dependency in your module (e.g. angular.module('myApp', ['ngSanitize'])). You are set (as long as you pass safe values to ngBindHtml) !
Use $sce to specify that certain stuff is explicitly trusted (by you) to be used as HTML:
.filter('textToIcon', function ($sce) {
return function (text) {
if (text) {
return $sce.trustAsHtml('');
}
};
})
The former approach is strongly recommended !

Applying variable to element jquery

I'm wondering if you can do this in jquery. I'm using version 1.10:
var myImage = $('#myImage');
What i basically want to do is assign the image as a variable so that i can use it anywhere. I want to use it during event handling:
E.g.
myImage.click(function () {
alert('Image Clicked');
});
If the above code is incorrect, I would really like to know the appropriate code.
Yes you can do it. In fact, it is recommended that you assign it to a variable so that you selector is not evaluated each time you use it. It is good for performance reasons.
Finding element by Id (such as in your case $('#myImage');) is fast but imagine if you have a selector like
$('ul > li.myClass:has(p) a:eq(2)')
Using a variable will speed things up for you in such scenarios.
I usually use $ sign in variable name like. var $varName = $('.selector') It helps me better understand the code and to distinguish between regular variables and variables that contain DOM elements.

Stylistic Question: Use of White Space

I have a particularly stupid insecurity about the aesthetics of my code... my use of white space is, frankly, awkward. My code looks like a geek dancing; not quite frightening, but awkward enough that you feel bad staring, yet can't look away.
I'm just never sure when I should leave a blank line or use an end of line comment instead of an above line comment. I prefer to comment above my code, but sometimes it seems strange to break the flow for a three word comment. Sometimes throwing an empty line before and after a block of code is like putting a speed bump in an otherwise smooth section of code. For instance, in a nested loop separating a three or four line block of code in the center almost nullifies the visual effect of indentation (I've noticed K&R bracers are less prone to this problem than Allman/BSD/GNU styles).
My personal preference is dense code with very few "speed bumps" except between functions/methods/comment blocks. For tricky sections of code, I like to leave a large comment block telling you what I'm about to do and why, followed by a few 'marker' comments in that code section. Unfortunately, I've found that some other people generally enjoy generous vertical white space. On one hand I could have a higher information density that some others don't think flows very well, and on the other hand I could have a better flowing code base at the cost of a lower signal to noise ratio.
I know this is such a petty, stupid thing, but it's something I really want to work on as I improve the rest of my skill set.
Would anyone be willing to offer some hints? What do you consider to be well flowing code and where is it appropriate to use vertical white space? Any thoughts on end of line commenting for two or three words comments?
Thanks!
P.S.
Here's a method from a code base I've been working on. Not my best, but not my worst by far.
/**
* TODO Clean this up a bit. Nothing glaringly wrong, just a little messy.
* Packs all of the Options, correctly ordered, in a CommandThread for executing.
*/
public CommandThread[] generateCommands() throws Exception
{
OptionConstants[] notRegular = {OptionConstants.bucket, OptionConstants.fileLocation, OptionConstants.test, OptionConstants.executable, OptionConstants.mountLocation};
ArrayList<Option> nonRegularOptions = new ArrayList<Option>();
CommandLine cLine = new CommandLine(getValue(OptionConstants.executable));
for (OptionConstants constant : notRegular)
nonRegularOptions.add(getOption(constant));
// --test must be first
cLine.addOption(getOption(OptionConstants.test));
// and the regular options...
Option option;
for (OptionBox optionBox : optionBoxes.values())
{
option = optionBox.getOption();
if (!nonRegularOptions.contains(option))
cLine.addOption(option);
}
// bucket and fileLocation must be last
cLine.addOption(getOption(OptionConstants.bucket));
cLine.addOption(getOption(OptionConstants.fileLocation));
// Create, setup and deploy the CommandThread
GUIInteractiveCommand command = new GUIInteractiveCommand(cLine, console);
command.addComponentsToEnable(enableOnConnect);
command.addComponentsToDisable(disableOnConnect);
if (!getValue(OptionConstants.mountLocation).equals(""))
command.addComponentToEnable(mountButton);
// Piggy-back a Thread to start a StatReader if the call succeeds.
class PiggyBack extends Command
{
Configuration config = new Configuration("piggyBack");
OptionConstants fileLocation = OptionConstants.fileLocation;
OptionConstants statsFilename = OptionConstants.statsFilename;
OptionConstants mountLocation = OptionConstants.mountLocation;
PiggyBack()
{
config.put(OptionConstants.fileLocation, getOption(fileLocation));
config.put(OptionConstants.statsFilename, getOption(statsFilename));
}
#Override
public void doPostRunWork()
{
if (retVal == 0)
{
// TODO move this to the s3fronterSet or mounts or something. Take advantage of PiggyBack's scope.
connected = true;
statReader = new StatReader(eventHandler, config);
if (getValue(mountLocation).equals(""))
{
OptionBox optBox = getOptionBox(mountLocation);
optBox.getOption().setRequired(true);
optBox.requestFocusInWindow();
}
// UGLY HACK... Send a 'ps aux' to grab the parent PID.
setNextLink(new PSCommand(getValue(fileLocation), null));
fireNextLink();
}
}
}
PiggyBack piggyBack = new PiggyBack();
piggyBack.setConsole(console);
command.setNextLink(piggyBack);
return new CommandThread[]{command};
}
It doesn't matter.
1) Develop a style that is your own. Whatever it is that you find easiest and most comfortable, do it. Try to be as consistent as you can, but don't become a slave to consistency. Shoot for about 90%.
2) When you're modifying another developer's code, or working on a group project, use the stylistic conventions that exist in the codebase or that have been laid out in the style guide. Don't complain about it. If you are in a position to define the style, present your preferences but be willing to compromise.
If you follow both of those you'll be all set. Think of it as speaking the same language in two different ways. For example: speaking differently around your friends than you do with your grandfather.
It's not petty to make pretty code. When I write something I'm really proud of, I can usually take a step back, look at an entire method or class, and realize exactly what it does at a glance - even months later. Aesthetics play a part in that, though not as large of a part as good design. Also, realize you can't always write pretty code, (untyped ADO.NET anyone?) but when you can, please do.
Unfortunately, at this higher level at least, I'm not sure there are any hard rules you can adhere to to always produce aesthetically pleasing code. One piece of advice I can offer is to simply read code. Lots of it. In many different frameworks and languages.
I like to break up logical "phrases" of code with white space. This helps others easily visualize the logic in the the method - or remind me when I go back and look at old code. For example, I prefer
reader.MoveToContent();
if( reader.Name != "Limit" )
return false;
string type = reader.GetAttribute( "type" );
if( type == null )
throw new SecureLicenseException( "E_MissingXmlAttribute" );
if( String.Compare( type, GetLimitName(), false ) != 0 )
throw new SecureLicenseException( "E_LimitValueMismatch", type, "type" );
instead of
reader.MoveToContent();
if( reader.Name != "Limit" )
return false;
string type = reader.GetAttribute( "type" );
if( type == null )
throw new SecureLicenseException( "E_MissingXmlAttribute" );
if( String.Compare( type, GetLimitName(), false ) != 0 )
throw new SecureLicenseException( "E_LimitValueMismatch", type, "type" );
The same break can almost be accomplished with braces but I find that actually adds visual noise and reduces the amount of code that can be visually consumed simultaneously.
Commens on code line
As for comments at the end of the line - almost never. The're not really bad, just easy to miss when scanning through code. And they clutter up the line taking away from the code making it harder to read. Our brains are already wired to grok line by line. When the comment is at the end of the line we have to split the line into two concrete concepts - code and comment. I say if it's important enough to comment on, put it on the line proceeding the code.
That being said, I do find one or two line hint comments about the meaning of a specific value are sometimes OK.
I find code with very little whitespace hard to read and navigate in, since I need to actually read the code to find logical structure in it. Clever use of whitespace to separate logical parts in functions can increase the ease of understanding the code, not only for the author but also for others.
Keep in mind that if you are working in an environment where your code is likely to be maintained by others, they will have spent the majority of their time looking at code that was not written by you. If your style distinctly differs from what they are used to seeing, your smooth code may be a speed bump for them.
I minimize white space. I put the main comment block above the code block and Additional end of line comments on the Stuff that may not be obvious to another dveloper. I think you are doing that already
My preferred style is probably anathema to most developers, but I will add occasional blank lines to separate what seem like appropriate 'paragraphs' of code. It works for me, nobody has complained during code reviews (yet!), but I can imagine that it might seem arbitrary to others. If other people don't like it I'll probably stop.
The most important thing to remember is that when you join an existing code base (as you almost always will in your professional career) you need to adhere to the code style guide dictated by the project.
Many developers, when starting a project afresh, choose to use a style based on the Linux kernel coding-style document. The latest version of that doc can be viewed at http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/CodingStyle;h=8bb37237ebd25b19759cc47874c63155406ea28f;hb=HEAD.
Likewise many maintainers insist that you use Checkpatch before submitting changes to version control. You can see the latest version that ships with the Linux kernel in same tree I linked to above at scripts/checkpatch.pl (I would link to it but I'm new and can only post one hyperlink per answer).
While Checkpatch is not specifically related to your question about whitespace usage, it will certainly help you eliminate trailing whitespace, spaces before tabs, etc.
Code Complete, by Steve McConnell (available in the usual locations) is my bible on this sort of thing. It has a whole chapter on layout and style that is just excellent. The whole book is just chock full of useful and practical advice.
I use exactly the same amount of whitespace as you :) Whitespace before methods, before comment blocks. In C, C++ the brackets also provide some "pseudo-whitespace" as there is only a single opening/closing brace on some lines, so this also serves to break up the code density.
Your code is fine, just do what you (and others you might work with) are comfortable with.
The only thing I see wrong with some (inexperienced) programmers about whitespace is that they can be afraid to use it, which is not true in this case.
I did however notice that you did not use more than one consecutive blank line in your sample code, which, in certain cases, you should use.
Here is how I would refactor that method. Things can surely still be improved and I did not yet refactor the PiggyBack class (I just moved it to an upper level).
By using the Composed Method pattern, the code becomes easier to read when it's divided into methods that each do one thing and work on a single level of abstraction. Also less comments are needed. Comments that answer to the question "what" are code smells (i.e. the code should be refactored to be more readable). Useful comments answer to the question "why", and even then it would be better to improve the code so that the reason will be obvious (sometimes that can be done by having a test that will fail without the inobvious code).
public CommandThread[] buildCommandsForExecution() {
CommandLine cLine = buildCommandLine();
CommandThread command = buildCommandThread(cLine);
initPiggyBack(command);
return new CommandThread[]{command};
}
private CommandLine buildCommandLine() {
CommandLine cLine = new CommandLine(getValue(OptionConstants.EXECUTABLE));
// "--test" must be first, and bucket and file location must be last,
// because [TODO: enter the reason]
cLine.addOption(getOption(OptionConstants.TEST));
for (Option regularOption : getRegularOptions()) {
cLine.addOption(regularOption);
}
cLine.addOption(getOption(OptionConstants.BUCKET));
cLine.addOption(getOption(OptionConstants.FILE_LOCATION));
return cLine;
}
private List<Option> getRegularOptions() {
List<Option> options = getAllOptions();
options.removeAll(getNonRegularOptions());
return options;
}
private List<Option> getAllOptions() {
List<Option> options = new ArrayList<Option>();
for (OptionBox optionBox : optionBoxes.values()) {
options.add(optionBox.getOption());
}
return options;
}
private List<Option> getNonRegularOptions() {
OptionConstants[] nonRegular = {
OptionConstants.BUCKET,
OptionConstants.FILE_LOCATION,
OptionConstants.TEST,
OptionConstants.EXECUTABLE,
OptionConstants.MOUNT_LOCATION
};
List<Option> options = new ArrayList<Option>();
for (OptionConstants c : nonRegular) {
options.add(getOption(c));
}
return options;
}
private CommandThread buildCommandThread(CommandLine cLine) {
GUIInteractiveCommand command = new GUIInteractiveCommand(cLine, console);
command.addComponentsToEnable(enableOnConnect);
command.addComponentsToDisable(disableOnConnect);
if (isMountLocationSet()) {
command.addComponentToEnable(mountButton);
}
return command;
}
private boolean isMountLocationSet() {
String mountLocation = getValue(OptionConstants.MOUNT_LOCATION);
return !mountLocation.equals("");
}
private void initPiggyBack(CommandThread command) {
PiggyBack piggyBack = new PiggyBack();
piggyBack.setConsole(console);
command.setNextLink(piggyBack);
}
For C#, I say "if" is just a word, while "if(" is code - a space after "if", "for", "try" etc. doesn't help readability at all, so I think it's better without the space.
Also: Visual Studio> Tools> Options> Text Editor> All Languages> Tabs> KEEP TABS!
If you're a software developer who insists upon using spaces where tabs belong, I'll insist that you're a slob - but whatever - in the end, it's all compiled. On the other hand, if you're a web developer with a bunch of consecutive spaces and other excess whitespace all over your HTML/CSS/JavaScript, then you're either clueless about client-side code, or you just don't give a crap. Client-side code is not compiled (and not compressed with IIS default settings) - pointless whitespace in client-side script is like adding pointless Thread.Sleep() calls in server-side code.
I like to maximize the amount of code that can be seen in a window, so I only use a single blank line between functions, and rarely within. Hopefully your functions are not too long. Looking at your example, I don't like a blank line for an open brace, but I'll have one for a close. Indentation and colorization should suffice to show the structure.