Hi all,
sometimes we use a WebView to load a local (or non local) HTML file.
To decrease the page overhead and speed up the page loading is good practice to minimize the size,
so remove all informations really not needed for code interpretation, but useful on development
process about user interation, like unused white spaces, comments, end of lines, tabulators etc.
See https://en.wikipedia.org/wiki/Minification_(programming)
This can be different but similar to when we compile eg. Java to bytecode, C++ to a binary file etc....
On this direction I've searched on the forum if someone already wrote some code to just pass
the HTML string and return a minified working string decreased on size.
I've searched it but seem no one have already wrote this, or not posted to the forum, so I tried to write it myself.
I wrote this, it works and return the full HTML as just one full long line decreasing by 15-20% factor the size.
It is a bit spartan and probably only works in my use case but not with all HTML + CSS + JS strings.
My question is.... There are better ways to do this ?
Thanks
I use it that way:
sometimes we use a WebView to load a local (or non local) HTML file.
To decrease the page overhead and speed up the page loading is good practice to minimize the size,
so remove all informations really not needed for code interpretation, but useful on development
process about user interation, like unused white spaces, comments, end of lines, tabulators etc.
See https://en.wikipedia.org/wiki/Minification_(programming)
This can be different but similar to when we compile eg. Java to bytecode, C++ to a binary file etc....
On this direction I've searched on the forum if someone already wrote some code to just pass
the HTML string and return a minified working string decreased on size.
I've searched it but seem no one have already wrote this, or not posted to the forum, so I tried to write it myself.
I wrote this, it works and return the full HTML as just one full long line decreasing by 15-20% factor the size.
It is a bit spartan and probably only works in my use case but not with all HTML + CSS + JS strings.
My question is.... There are better ways to do this ?
Thanks
B4X:
Private Sub MinifyHTMLFile(Original As StringBuilder) As ResumableSub
Dim isStyle As Boolean = False
Dim isScript As Boolean = False
Dim isMultilineComment As Boolean = False
Dim Minified, FinalMinified, Styles, Scripts As StringBuilder
Minified.Initialize
FinalMinified.Initialize
Styles.Initialize
Scripts.Initialize
Dim lines() As String = Regex.Split(CRLF, Original.ToString)
Log("NUMBER OF LINES: " & lines.Length)
For i = 0 To lines.Length-1
Dim line As String = lines(i).Trim
If line.Length = 0 Then
Log("Found void string on line " & (i+1))
Else
If line.StartsWith("<style>") Then
isStyle = True
Minified.Append(line).Append(CRLF)
Log("LINE [ " & (i+1) & "]: " & line & " [START STYLE]")
Else If line.StartsWith("</style>") Then
isStyle = False
Minified.Append(Styles.ToString).Append(CRLF)
Minified.Append(line).Append(CRLF)
Log("LINE [ " & (i+1) & "]: " & line & " [END STYLE]")
Log("FULL STYLE: [" & Styles.ToString & "]")
Else If line.StartsWith("<script>") Then
isScript = True
Minified.Append(line).Append(CRLF)
Log("LINE [ " & (i+1) & "]: " & line & " [START SCRIPT]")
Else If line.StartsWith("</script>") Then
isScript = False
Minified.Append(Scripts.ToString).Append(CRLF)
Minified.Append(line).Append(CRLF)
Log("LINE [ " & (i+1) & "]: " & line & " [END SCRIPT]")
Log("FULL Script: [" & Scripts.ToString & "]")
Else If line.StartsWith("<") And line.EndsWith(">") Then
Minified.Append(line).Append(CRLF)
Log("LINE [ " & (i+1) & "]: " & line & " [HTML TAG]")
Else
If line.StartsWith("/*") Then isMultilineComment = True 'MULTILINE COMMENT
If isStyle Then
If line.StartsWith("//") = True Then
Log("Found Full Line [STYLE] comment on line " & (i+1) & " -> [" & line & "]")
Else
If line.Contains("//") = False Then
If isMultilineComment = False Then
Styles.Append(line)
Log("LINE [ " & (i+1) & "]: " & line & " [STYLE]")
Else
Log("LINE [ " & (i+1) & "]: " & line & " [STYLE MULTILINE COMMENT]")
End If
Else
Dim n As Int = line.IndexOf("//")
Dim comment As String = line.SubString(n).Trim
Dim tmp As String = line.SubString2(0, n).Trim
Styles.Append(tmp)
Log("Found Partial Line [STYLE] comment on line " & (i+1) & " -> [" & comment & "] LINE WITHOUT COMMENTS -> [" & tmp & "]")
End If
End If
Else If isScript Then
If line.StartsWith("//") = True Then
Log("Found Full Line [SCRIPT] comment on line " & (i+1) & " -> [" & line & "]")
Else
If line.Contains("//") = False Or line.Contains("\/") = True Then ' We add Escape
If isMultilineComment = False Then
Scripts.Append(line)
Log("LINE [ " & (i+1) & "]: " & line & " [SCRIPT]")
Else
Log("LINE [ " & (i+1) & "]: " & line & " [SCRIPT MULTILINE COMMENT]")
End If
Else
Dim n As Int = line.IndexOf("//")
Dim comment As String = line.SubString(n).Trim
Dim tmp As String = line.SubString2(0, n).Trim
Scripts.Append(tmp)
Log("Found Partial Line [SCRIPT] comment on line " & (i+1) & " -> [" & comment & "] LINE WITHOUT COMMENTS -> [" & tmp & "]")
End If
End If
End If
If line.EndsWith("*/") Then isMultilineComment = False
End If
' Sleep(0)
End If
Next
LogColor("MINIFIED MULTILINE:", xui.Color_Green)
'''''' Log it line by line
Dim lines() As String = Regex.Split(CRLF, Minified.ToString)
For Each line As String In lines
LogColor(line, xui.Color_Yellow)
Next
FinalMinified.append(Minified.ToString.Replace(CRLF, "")) ' Make it one line
LogColor("NO MINIFIED Size: " & Original.Length & " Bytes", xui.Color_Red)
LogColor("MINIFIED Size: " & FinalMinified.Length & " Bytes", xui.Color_Red)
LogColor("Size decreased by a factor of " & NumberFormat(100 - MapFloat(FinalMinified.Length, 0, Original.Length, 0, 100), 0, 2) & " percent", xui.Color_Green)
Return FinalMinified
End Sub
'Re-maps a Float number from one range to another.
Sub MapFloat(Value As Float, fromLow As Float, fromHigh As Float, toLow As Float, toHigh As Float) As Float
Return ( (Value - fromLow) * (toHigh - toLow) / (fromHigh - fromLow) + toLow )
End SubI use it that way:
B4X:
CreateHTMLString
Wait For (MinifyHTMLFile(mFullHTML)) Complete (Minified As StringBuilder)
SaveHTMLFile(Minified.ToString)
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