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Re: Clean up HTML content

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W dniu 2013-03-06 23:45, Thomas 'PointedEars' Lahn pisze:
> Cezary Tomczyk wrote:
>
>> W dniu 2013-03-06 00:03, Thomas 'PointedEars' Lahn pisze:
[...]

> I said: The code that you posted (IMHO) *is* self-explanatory, and _not_
> badly formatted.  IOW, (IMHO) it is *OK* for posting even *without*
> additional comments.

Ok.

>> [...]
>>>> Here's the code:
>>>>
>>>> var is_block_style = function (el) {
>>>>        var el_style;
>>>>        if (window.getComputedStyle) {
>>>
>>> You should feature-test this method in a way that does not primarily use
>>> implicit type conversion.  There is one DOM implementation, MSHTML, that
>>> is notorious for throwing strange exceptions on properties of type
>>> "unknown" otherwise.  See also, e.g., jsx.object.isHostMethod().
>     ^^^^^^^^^                             ^^^^^^^^^^^^^^^^^^^^^^^^^
>> Yes, I know that IE return sometimes "object", sometimes "function".
>
> More importantly, sometimes the result of the “typeof” operation is
> “"unknown"” there (I hope the additional quotes make it clear now).  And
> then a type-converting test throws an exception.  So a type-converting test
> cannot be considered appropriate for feature-testing host object's methods.
> It is insufficient for testing native object's methods already.

That's surprising me, I mean about "unknown". I never saw it before.

>> However, I had never any problems with implicit type conversion like
>> above.
>
> Lucky you.

Probably.

[...]

>> jsx.object.isMethodType = function (s) {
>    ^^^^^^^^^^^^^^^^^^^^^^^
>>     return /^\s*(function|object|unknown)\s*$/i.test(s);
>> };
>
> … and no; evidently the name of the method I mentioned is different.  The
> actual method *actually* is too long to be posted here.  It can be found in
>
> <http://pointedears.de/websvn/filedetails.php?repname=JSX&path=%2Ftrunk%2Fobject.js>
>
> which in turn can be easily found with a Web search.

isHostMethod is the same as isMethod, as I see:

jsx.object.isHostMethod = jsx.object.areHostMethods = jsx.object.isMethod;

>>>>            el_style = window.getComputedStyle(el,
>>>> null).getPropertyValue('display');
>>>>        } else {
>>>>            el_style = el.currentStyle.display;
>>>>        }
>>>>        return el_style;
>>>> };
>>>
>>> You should generalize this code, see also jsx.dom.getComputedStyle().  In
>>
>> I do not see here
>>
> http://pointedears.de/websvn/filedetails.php?repname=JSX&path=%2Ftrunk%2Fdom.js
>> method getComputedStyle.
>
> Because it requires *CSS* (D)OM capabilities.  For historical reasons it is
> not available as jsx.dom.css.getComputedStyle(), though.
>
> <http://pointedears.de/websvn/filedetails.php?repname=JSX&path=%2Ftrunk%2Fdom%2Fcss.js>
>
> That, too, can be easily found with a Web search.

Would be nice to have same input search field to search through SVN files.

I found jsx.dom.getComputedStyle and seems it's code looks not so big.

> Try to be more careful in all respects, please.

I'll try.

>>> this case, because the base object always is the same, you can even
>>> safely perform the branching for the window.getComputedStyle() DOM method
>>> – which should be document.defaultView.getComputedStyle() to be
>>> compatible – only once.  You cannot assume, however, that if the
>>> getComputedStyle() method is absent, the “currentStyle“ property must be
>>> present; that is an inductive fallacy (hasty generalization).
>>
>> Hm, both sources:
>>
>> * https://developer.mozilla.org/en-US/docs/DOM/window.getComputedStyle
>
> Keep in mind that this is a wiki.  Anyone logged in can write any nonsense
> there.  And anyone logged in can correct it.  If they learn about it.

"Anyone can write nonsense, anyone can correct it." - how to trust in 
that sources then? Hm...

>> * http://msdn.microsoft.com/en-us/library/ie/ff975168%28v=vs.85%29.aspx
>>
>> says about window.getComputedStyle. That's why I used this method.
>>
>> However, when I look at David Mark method getKomputedStyle seems it's
>> quite complicated :-(
>
> So there *actually* *is* *more* than Firefox and Internet Explorer? ;-)

Ou, yes :-)

> Seriously though, I remember to have observed several versions of Safari 4
> not having window.getComputedStyle() but
> document.defaultView.getComputedStyle().  The Gecko DOM, and the MSHTML 9
> DOM in Standards Mode, have both.
>
> So far, document.defaultView.getComputedStyle() is the more standards-
> compliant approach because:
>
> 1. “document” implements the “DocumentView” interface of W3C DOM Level 2
>     Views [DOM2Views].
>
> 2. “document.defaultView” implements the “ViewCSS” interface of
>     W3C DOM Level 2 Style CSS [DOM2CSS], which inherits from the
>     “AbstractView” interface of [DOM2Views].
>
> 3. “getComputedStyle” is a method provided by “ViewCSS” interface. (ibid.)
>
> (The reference to [HTML5] in [DOM2Views] appears to be a dead end here; the
> “Window” interface of [HTML5] does not provide a “getComputedStyle” method.)
>
> ______________
> [DOM2Views] <http://www.w3.org/TR/DOM-Level-2-Views/> p.
> [DOM2CSS]   <http://www.w3.org/TR/DOM-Level-2-Style/css.html#CSS-ViewCSS>
> [HTML5]     <http://www.w3.org/TR/html5/dom.html#the-document-object> pp.

Thank you for nice explanation. Also, method jsx.dom.getComputedStyle 
looks good.

>>>> var imgClassName = 'testimg';
>>>>
>>>> var tidyHTML = function (node) {
>>>>        var elms = node.childNodes,
>>>>            i = elms.length,
>>>>            text = '',
>>>>            elm;
>>>>
>>>>        if (!node.hasChildNodes()
>>>
>>> I have never used that method before.  Unless you are sure about its
>>> backwards-compatibility, you should replace the call with
>>
>> I use https://developer.mozilla.org/en-US/docs/DOM/Node.hasChildNodes
>> from long time. Sesms it's implemented long time ago. See:
>> http://www.quirksmode.org/dom/w3c_core.html
>
> It was *specified* a long time ago.  I rather do my own tests instead of
> relying on MDN or Quirks Mode.

Yes, many things can be specified, but not implemented. However, 
theoretically, we should check if there are exists all methods before 
using them. More over, they can work with a very different way that that 
is expected. Is not it already fall into an paranoid? I do not know.

>>>>        && (node.nodeName.toLowerCase() === 'img'
>>>> && !(new RegExp('(^|\\s)' + imgClassName +
>>>          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>>> '(\\s|$)')).test(node.className))) {
>>>     ^^^^^^^^^^^
>>> You should move or even generalize this code in order to leverage
>>> caching.
>>
>> Move new RegExp outside of method to do not creating new objects RegExp
>> everytime?
>
> Yes.

Sure. Will do this.

> My next idea is that you can globally cache references to RegExp instances
> that do not have the “global” flag set.  But it is perhaps not applicable
> here.
>
>>> You can do that because the RegExp does not have the “global” flag set
>     ^^^^^^^^^^^^^^^
> Meaning: “You can create the RegExp instance only once because …”

Yes. I thought about only once instance to save memory and more 
efficient running code.

>>> (i.e.,  its boolean ”global” property has the value “false”).
>>
>> Right. I should set "global" as "true".
>
> No, I did _not_ suggest that you should make that mistake:

>    var rx = /foo/g;
>    var s = "foo";
>
>    /* true */
>    rx.test(s)
>
>    /* false */
>    rx.test(s)
>
>    /* true */
>    rx.test(s)

Correct me if I am wrong: in fact boolean "global" should be false 
because I need to find at least one "class name". No need to find all of 
them. Except when I want to remove them.

[...]

>> Because sometimes I removing node.
>
> How does that explain the opposite direction of the concatenation?

I suppose it doesn't have to be opposite direction.

>>> Equivalent code:
>>>
>>>     var a = ["foo", "bar", "baz"];
>>>     var i = a.length;
>>>     var a2 = [];
>>>     while (i--)
>>>     {
>>>       if (a[i] != "bar")
>>>       {
>>>         a2.push(a[i]);
>>>       }
>>>     }
>>>
>>>     /* ["baz", "foo"] */
>>>     console.log(a2);
>>>
>>> You are looking for something more like
>>>
>>>     for (var i = 0, len = elms.length; i < len; ++i)
>>>     {
>>>       text += tidyHTML(elms[i]);
>>>     }
>>
>> Not really. In short: I want to remove all html nodes, except img with
>> specified class name + I need to care about formatting, eg. if text is
>> in block element then I apply <br/> after plain text.
>
> I am aware of that, but ISTM that you will still have to append/concatenate
> in the direction of the iteration or you will have the original content
> reduced *and* backwards.

Possible. Will try other ways also.

>>>>        }
>>>>
>>>>        if (typeof text !== 'undefined') {
>>>
>>> Again an unnecessary strict comparison.
>>
>> JSLint case.
>
> Learn how to configure it, or use a better tool.

I know that JSLint have an options, but sometimes you can not just turn 
it off, eg. when you working with group that accepted some rules.

>>>>            if (is_block_style(node) === 'block') {
>>>>                node.parentNode.insertBefore(document.createElement('br'),
>>>> node.nextSibling);
>>>>            }
>>>
>>> Why?  Usually it is misuse of the “br” element to use it as replacement
>>> for a block delimiter.  Also, “display: block” does not necessarily mean
>>> that there is a paragraph.  Consider, for example, positioned or floating
>>> block elements.
>>
>> Yes, I now saw the method getKomputedStyle from MyLibrary.
>
> JFTR: You are not posting the URI of code you are referring to either.

I run into my own trap. I asked about the same before you :-)

>> Unfortunately, it's quite complicated :/ I do not know about JSX similar
>> method.
>
> I seriously hope there is none.  What a bloat:
>
> <https://github.com/cinsoft/My-Library/blob/master/mylib.asp#L2329>

Yes. I also found it :-)

-- 
Cezary Tomczyk
http://www.ctomczyk.pl/

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Thread

Clean up HTML content Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-05 08:48 +0100
  Re: Clean up HTML content Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-05 17:55 +0100
    Re: Clean up HTML content Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-05 20:25 +0100
      Re: Clean up HTML content Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-06 00:03 +0100
        Re: Clean up HTML content Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-06 00:08 +0100
          Re: Clean up HTML content Dr J R Stockton <reply1300@merlyn.demon.co.uk.invalid> - 2013-03-06 22:06 +0000
            Re: Clean up HTML content Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2013-03-10 01:14 +0100
        Re: Clean up HTML content Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-06 22:02 +0100
          Re: Clean up HTML content Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-06 23:45 +0100
            Re: Clean up HTML content Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-09 11:29 +0100
              Re: Clean up HTML content Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2013-03-09 16:11 +0100
  Re: Clean up HTML content Danny <dann90038@gmail.com> - 2013-03-07 14:28 -0800
    Re: Clean up HTML content Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2013-03-09 11:37 +0100
      Re: Clean up HTML content dann90038@gmail.com - 2013-03-09 11:44 -0800

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