How to remove all extra spaces, blank lines, and CrLfs in JavaScript code?

[dreammanor]

I want to use RegExp to remove all extra spaces, blank lines, and carriage returns and line breaks in JavaScript code to achieve the purpose of compressing JavaScript code. Is there some simple way to achieve this? Thanks!

Edit:
Solutions that do not use RegExp are also acceptable, which means that any method is acceptable and worth discussing.

[techgnome]

Commonly used mechanism is a utility called minify ... I think it will also do some semblance of obfuscation in the process as a byproduct... but it really compacts things down pretty tightly. I've painfully deconstructed scripts that have been through it... It's pretty widely used.


-tg

[techgnome]

the reason the obfuscation is a side effect is because as part of the minification, variables are renamed from `yourVeryLongVariableName` to `a` to help shrink things down.

-tg

[dreammanor]

Commonly used mechanism is a utility called minify ... I think it will also do some semblance of obfuscation in the process as a byproduct... but it really compacts things down pretty tightly. I've painfully deconstructed scripts that have been through it... It's pretty widely used.

Yes. I've tested UglifyJS and it works fine under Windows 10, but it does not work under XP. I've spent a lot of time and effort on compressing JavaScript code, and in the end, I had to take the worst approach: write a JavaScript code compression program from scratch.

the reason the obfuscation is a side effect is because as part of the minification, variables are renamed from `yourVeryLongVariableName` to `a` to help shrink things down.

This is exactly what I need, because I want the published web pages to be as small as possible and as fast as possible.

[techgnome]

works fine under Windows 10, but it does not work under XP

That makes no sense.. unless you're changing browsers...but you minify the code once.... and publish the minified code to the website.... so it shouldn't matter what OS you're using... Unless you mean the results didn't work... but then you may need to look at what your'e doing and what is/isn't supported by the browser... but that's browser-based not OS-based.



-tg

[Zvoni]

That makes no sense.. unless you're changing browsers...but you minify the code once.... and publish the minified code to the website.... so it shouldn't matter what OS you're using... Unless you mean the results didn't work... but then you may need to look at what your'e doing and what is/isn't supported by the browser... but that's browser-based not OS-based.



-tg

Ah, tg, but it makes sense, if you presume that XP is his developing-machine.....
And yes, that is another can of worms......

[Shaggy Hiker]

This doesn't seem to have anything to do with VB6 anymore, so you are likely to get better responses here. Minification is what you are trying to achieve. The tools are out there, and are likely to do better than anything you would write yourself, so the question is just about finding one that works on your development machine, which isn't a VB6 question.

[ChrisE]

Shaggy was quicker moving this thread

here a start with removing blank/empty lines
I tested it with loading a Textfile to a Richtextbox

here the code

Option Explicit

Public Function ReadFile(ByRef Path As String) As String
   Dim FileNr As Long
   On Error Resume Next
   If FileLen(Path) = 0 Then Exit Function
   On Error GoTo 0
   FileNr = FreeFile
   Open Path For Binary As #FileNr
   ReadFile = Space$(LOF(FileNr))
   Get #FileNr, , ReadFile
   Close #FileNr
End Function

Private Sub Command1_Click()
RichTextBox1.text = ReadFile("D:\Textd.txt")
End Sub

Private Sub Command2_Click()
RichTextBox2.text = fChangeText(RichTextBox1.text)
End Sub

Public Function fChangeText(sText As String) As String
    Dim regex As Object
    Set regex = CreateObject("Vbscript.Regexp")
    With regex
        .Pattern = "^\s*$[\r\n]*" 'remove empty lines
        .MultiLine = True
        .Global = True
        fChangeText = .Replace(sText, "")
    End With
    Set regex = Nothing
End Function

don't know if you want to do this further

hth

[dreammanor]

This doesn't seem to have anything to do with VB6 anymore, so you are likely to get better responses here. Minification is what you are trying to achieve. The tools are out there, and are likely to do better than anything you would write yourself, so the question is just about finding one that works on your development machine, which isn't a VB6 question.

Hi @Shaggy Hiker, this thread is about VB6. I hope I can achieve my goal in the following ways:
(1) Pure VB6
(2) VB6 + VBScript.RegExp
(3) VB6 + RC5
(4) VB6 + third-party components
(5) VB6 + any other methods

(6) Of course, pure JavaScript methods are also acceptable.

In fact, any questions I ask on this forum are related to VB6. I want to use VB6 to accomplish everything I need.

[dreammanor]

Shaggy was quicker moving this thread

here a start with removing blank/empty lines
I tested it with loading a Textfile to a Richtextbox

here the code

Option Explicit

Public Function ReadFile(ByRef Path As String) As String
   Dim FileNr As Long
   On Error Resume Next
   If FileLen(Path) = 0 Then Exit Function
   On Error GoTo 0
   FileNr = FreeFile
   Open Path For Binary As #FileNr
   ReadFile = Space$(LOF(FileNr))
   Get #FileNr, , ReadFile
   Close #FileNr
End Function

Private Sub Command1_Click()
RichTextBox1.text = ReadFile("D:\Textd.txt")
End Sub

Private Sub Command2_Click()
RichTextBox2.text = fChangeText(RichTextBox1.text)
End Sub

Public Function fChangeText(sText As String) As String
    Dim regex As Object
    Set regex = CreateObject("Vbscript.Regexp")
    With regex
        .Pattern = "^\s*$[\r\n]*" 'remove empty lines
        .MultiLine = True
        .Global = True
        fChangeText = .Replace(sText, "")
    End With
    Set regex = Nothing
End Function

don't know if you want to do this further

hth

Hi ChrisE, your code is a good start. But there are many other complicated situations to consider when removing extra spaces in JavaScript text, such as:
(1) Cannot remove spaces in "strings" (wrapped in single or double quotes)
(2) Cannot remove spaces or blank lines in "multi-line strings" (strings wrapped with "` ").

[dreammanor]

Hi @Shaggy Hiker,
Maybe this thread should be moved back to the VB6 sub-forum.

Hi @ChrisE,
I just uploaded a test program. If you are interested, please help check if it can be further optimized. Thanks.

http://www.vbforums.com/showthread.p...=1#post5446537

[kfcSmitty]

Hi @Shaggy Hiker,
Maybe this thread should be moved back to the VB6 sub-forum.

Hi @ChrisE,
I just uploaded a test program. If you are interested, please help check if it can be further optimized. Thanks.

http://www.vbforums.com/showthread.p...=1#post5446537

Randomish question about your other thread: why are you replacing let with var? Are you working with clients that do not support ECMAScript 2015?

If so, you're now looking at not only minifying a file, you're also getting into transpiling territory, which is a whole other can of worms. I would either recommend not transpiling at all (IE don't replace let, const, etc.), otherwise it could be confusing with people, changing how their script is meant to work.

[dreammanor]

Randomish question about your other thread: why are you replacing let with var? Are you working with clients that do not support ECMAScript 2015?

If so, you're now looking at not only minifying a file, you're also getting into transpiling territory, which is a whole other can of worms. I would either recommend not transpiling at all (IE don't replace let, const, etc.), otherwise it could be confusing with people, changing how their script is meant to work.

Yes, my XP development environment does not support ECMAScript 2015. All my programs are developed on XP, but run on Windows 10. This makes it impossible for me to debug JavaScript while developing.

I know that simply replacing let with var is not a good idea, and I don't plan to do it. I'm just using this example to test the speed of different regular expression engines.

[PlausiblyDamp]

Yes, my XP development environment does not support ECMAScript 2015. All my programs are developed on XP, but run on Windows 10. This makes it impossible for me to debug JavaScript while developing.

I know that simply replacing let with var is not a good idea, and I don't plan to do it. I'm just using this example to test the speed of different regular expression engines.

Have you considered incorporating something like https://babeljs.io into your pipeline? It can handle transpiling between versions for you and it can also cope with minification etc. as well.

[dreammanor]

Have you considered incorporating something like https://babeljs.io into your pipeline? It can handle transpiling between versions for you and it can also cope with minification etc. as well.

I haven't tested Babel on XP, but I checked the source code of Babel and it seems to use more ECMAScript 2015 syntax than UglifyJS. I guess the new version of Babel should not run on XP. Unless I look for and try those very old versions of Babel.

[Prahlad]

using this site that is remove all unnecessary code

http://www.odditysoftware.com/page-webtools16.htm