FAQ Topic - How do I access a frame's content? (2009-10-25)

In comp.lang.javascript message <e317ec92-048b-4d6d-be38-ce3e14a5933a@j4
g2000yqe.googlegroups.com>, Wed, 28 Oct 2009 17:30:34, VK
<schools_ring (AT) yahoo (DOT) com> posted:

Dr J R Stockton wrote:
In effect, I want to read the file, HTML or TXT, as it exists on disc.

VK wrote:
You cannot do it for the reason explained at
http://groups.google.com/group/comp.lang.javascript/msg/d9f3f6724bada573

Dr J R Stockton wrote:
Unconvincing, because I *am* doing it,

You don't, it is your delusion.

to the extent that is essential
for the task. *If you consider under what circumstances what can work,
you should be able to deduce how and why I am doing it.

I don't know how and why are you doing it, but it was stated that "I
want to read the file, HTML or TXT, as it exists on disc." As long as
you are not using AJAX calls - and you don't - you are not able and
you are not reading any files "HTML or TXT, as it exists on disc" -
however wide the definition "as it exists on disc" would be taken.

Give or take irrelevant questions of character coding and newline
representation, I have been getting, by using innerHTML and by using
innerText, a string which agrees visually with the content of a TXT file
on disc, as would be shown by Notepad.

I still WANT to read a HTML file correspondingly, seeing the source
lines as per Notepad; but I don't really NEED to, since what I can get
suffices for that part of the desired work that is NECESSARY.

As much as I can understand you request, you want to get the textual
data from the loaded document in full and without omission which is
doable but it is a completely different task.

Yes, that is what I still WANT. But it is more than, in the case of an
HTML page, I really NEED. Therefore progress is being made.



Associated query : I have read a TXT file from disc, getting a matching
string. It consists of many lines containing words separated by
punctuation. They all start with the same sequence of words and
punctuation (improbably, zero length), but after that there is always
non-zero length. No two lines completely agree. What is the nicest way
of determining the common part AND obtaining in sequence strings for the
varying parts? Think of it as like a representation of a directory
tree.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 MIME.
Web <URL:http://www.merlyn.demon.co.uk/> - FAQish topics, acronyms, & links.
Proper <= 4-line sig. separator as above, a line exactly "-- " (SonOfRFC1036)
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Dr J R Stockton wrote:

In comp.lang.javascript message <hca8q9$4j1$1 (AT) news (DOT) eternal-
september.org>, Wed, 28 Oct 2009 12:16:06, Garrett Smith
dhtmlkitchen (AT) gmail (DOT) com> posted:
As I explained, the innerText/textContent is not related to the frame;
it is related to elements. An entry on getting frame's
innerText/textContent implies that a frame has a property
innerText/textContent. That would be false.

In a FAQ, answers should be classified according to the nature of the
question, not according to the nature of the answer.

A common reasoning for questioning is that the answer is not where the
questioner thought to look.

In ordinary English, a frame, or at least an iframe, does commonly have
an innerText or textProperty property; but it is kept by one of its
descendants.

The IFRAME element and the frame (as in frames[0] or
anIframe.contentWindow), are different.

It is important to be clear on the distinction. These are technical
terms, not ordinary English terms.

Ask the average elderly person whether they have grandchildren.
Commonly the answer will be "Yes"; it will not be "No; but I have
children who have children".

So what?

Anyway, the FAQ said "9.2 How do I access a frame's content?", rightly
omitting any reference to the structure within the frame.

The "content" would be in the document.

--
Garrett
comp.lang.javascript FAQ: http://jibbering.com/faq/

Garrett Smith wrote:

Dr J R Stockton wrote:
In comp.lang.javascript message <hca8q9$4j1$1 (AT) news (DOT) eternal-
september.org>, Wed, 28 Oct 2009 12:16:06, Garrett Smith
dhtmlkitchen (AT) gmail (DOT) com> posted:
As I explained, the innerText/textContent is not related to the frame;
it is related to elements. An entry on getting frame's
innerText/textContent implies that a frame has a property
innerText/textContent. That would be false.

In a FAQ, answers should be classified according to the nature of the
question, not according to the nature of the answer.

A common reasoning for questioning is that the answer is not where the
questioner thought to look.

In ordinary English, a frame, or at least an iframe, does commonly have
an innerText or textProperty property; but it is kept by one of its
descendants.

The IFRAME element and the frame (as in frames[0] or
anIframe.contentWindow), are different.

It is important to be clear on the distinction. These are technical
terms, not ordinary English terms.

Don't be ridiculous. The standards-compliant `textContent' property of the
object referred to by the standards-compliant `contentDocument' property of
an `iframe' element object (which is the same as the object referred to by
the `document' property of the object referred to by the proprietary
`contentWindow' property of an `iframe' element object) undoubtedly provides
access to the `iframe''s content.

Ask the average elderly person whether they have grandchildren.
Commonly the answer will be "Yes"; it will not be "No; but I have
children who have children".

So what?

So you are being deliberately obtuse.

Anyway, the FAQ said "9.2 How do I access a frame's content?", rightly
omitting any reference to the structure within the frame.

The "content" would be in the document.

And if the document would be a plain text document, the `textContent'
property of wrapping document element object would yield exactly its
content.


PointedEars
--
Anyone who slaps a 'this page is best viewed with Browser X' label on
a Web page appears to be yearning for the bad old days, before the Web,
when you had very little chance of reading a document written on another
computer, another word processor, or another network. -- Tim Berners-Lee

Thomas 'PointedEars' Lahn wrote:

Garrett Smith wrote:

Dr J R Stockton wrote:
In comp.lang.javascript message <hca8q9$4j1$1 (AT) news (DOT) eternal-
september.org>, Wed, 28 Oct 2009 12:16:06, Garrett Smith
dhtmlkitchen (AT) gmail (DOT) com> posted:
As I explained, the innerText/textContent is not related to the frame;
it is related to elements. An entry on getting frame's
innerText/textContent implies that a frame has a property
innerText/textContent. That would be false.
In a FAQ, answers should be classified according to the nature of the
question, not according to the nature of the answer.

A common reasoning for questioning is that the answer is not where the
questioner thought to look.

In ordinary English, a frame, or at least an iframe, does commonly have
an innerText or textProperty property; but it is kept by one of its
descendants.
The IFRAME element and the frame (as in frames[0] or
anIframe.contentWindow), are different.

It is important to be clear on the distinction. These are technical
terms, not ordinary English terms.

Don't be ridiculous. The standards-compliant `textContent' property of the
object referred to by the standards-compliant `contentDocument' property of
an `iframe' element object (which is the same as the object referred to by
the `document' property of the object referred to by the proprietary
`contentWindow' property of an `iframe' element object) undoubtedly provides
access to the `iframe''s content.

The iframe contents could be an image, an HTML document with a
Flash movie, javascript, a canvas.

The IFRAME content, in those cases, is what?
frame.contentWindow.document.textContent? Wow. You're so smart.

In contrast, there is a node that has a textContent or innerText
property. That node may have a document, which may have a parentWindow,
and the |parent| of that parentWindow may be including that resource via
an IFRAME or FRAME element.

Ask the average elderly person whether they have grandchildren.
Commonly the answer will be "Yes"; it will not be "No; but I have
children who have children".
So what?

So you are being deliberately obtuse.
No, I am correct.

As long as I have something to say about it, the entry will correctly
explain how to access the window object of the IFRAME.

A frame's content window can be found from the frames collection.

And from there, the window has a document, which has a |getElementById|,
a |forms| property, etc. All standard fare, basic stuff.

Anyway, the FAQ said "9.2 How do I access a frame's content?", rightly
omitting any reference to the structure within the frame.

The "content" would be in the document.

And if the document would be a plain text document, the `textContent'
property of wrapping document element object would yield exactly its
content.

DOM properties on elements in a plain text document?

Browsers do create HTML documents for text/plain documents and give a
quirks mode dom.

It isn't standard, though, is it?
--
Garrett
comp.lang.javascript FAQ: http://jibbering.com/faq/

In comp.lang.javascript message <1486365.uhbGJ8BuQJ (AT) PointedEars (DOT) de>,
Thu, 29 Oct 2009 19:50:30, Thomas 'PointedEars' Lahn
<PointedEars (AT) web (DOT) de> posted:

Dr J R Stockton wrote:

Thomas 'PointedEars' Lahn posted:
Dr J R Stockton wrote:
Thomas 'PointedEars' Lahn posted:
Dr J R Stockton wrote:
I want to read as on disc, certainly; but my needs are substantially
satisfied for TXT files by what innerText and innerHTML show, and for
HTML files by what is actually revealed.

It's annoying that Firefox seems to lack innerText of iframe content,

It implements the `textContent' property instead, like any other
browser
standards-compliant in that regard. (Discussed here ad nauseam).

I see. Then why did you not suggest that <FAQENTRY> it should be
included in the frame-content section (9.2) of the FAQ?

Because I do not think it is a frequently asked question.

Then why did you not suggest that the section be removed?

Because I was not aware of its existence to date (obviously I never had a
problem that required searching the comp.lang.javascript FAQ for it),

There have been sections in the FAQ on frames for *at least* four years
(w.e.f. Thursday next); Google and Wayback will show many instances.

You very frequently advise people, in a peremptory manner, to search the
archives before posting.

You will have seen posted here, in FAQ sections and elsewhere,
injunctions to read the FAQ.

The FAQ begins with an index to its sections and subsections, naming
their Subjects.

Those subsections will have been posted to the newsgroup on a regular
basis by Bart.

Therefore, you should have KNOWN that the FAQ contained material on
frames; and, in any case, you should have suspected it.

Hypocrite.

It's still annoying that one major browser lacks what others have (even
if out of fashion), especially if the functionality is present.

Which browser would that be?

With a little more - with any - humility and/or common sense, you would
read what you quote both before and after composing a reply. The answer
to that question is plainly visible above, currently at the >>>> level.

I have asked before because that implication of yours would be incorrect.
Firefox/Gecko does not lack what others have; IE/MSHTML does lack it. While
probably not in number of installations, `textContent' is the standards-
compliant approach which is supported by more current layout engines than
`innerText' is or is going to be.

Firefox apparently lacks what the most-used browser (MSIE), and three
other major PC browsers, have - innerText of iframe content.

It is of course also a pity that IE lacks textContent - however, it is
unreasonable to expect (except in Nelson's context) Microsoft to heed
international standards.

SOP?
OAF.

Sorry, I am not familiar with that acronym, and it is not listed on
http://www.merlyn.demon.co.uk/acronyms.htm#Acro> or in the usual places.

Indeed not. You are incorrect in assuming it there to be an acronym.
It is a well-known long-established English word, derived from the Norse
: according to Google, the Norwegians and Icelanders still use it. You
have just proved it apt. (As an acronym, it can be found at
<http://www.acronymfinder.com/OAF.html>, with 14 meanings.)

It's a good idea to read the newsgroup c.l.j and its FAQ. See below.

--
(c) John Stockton, nr London UK. ?@merlyn.demon.co.uk IE7 FF3 Op9 Sf3
news:comp.lang.javascript FAQ <URL:http://www.jibbering.com/faq/index.html>.
<URL:http://www.merlyn.demon.co.uk/js-index.htm> jscr maths, dates, sources.
<URL:http://www.merlyn.demon.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.

In comp.lang.javascript message <hcdshu$ds2$1 (AT) news (DOT) eternal-
september.org>, Thu, 29 Oct 2009 22:11:19, Garrett Smith
<dhtmlkitchen (AT) gmail (DOT) com> posted:

As long as I have something to say about it, the entry will correctly
explain how to access the window object of the IFRAME.

You are supposed, as FAQ maintainer, to be sustaining something useful
to the ordinary questioners, especially those who are not full-time
professional JavaScript programmers.

However, you appear entirely unable to understand their positions and
points of view. FAQ maintaining is a task for the sympathetic
communicator; not for the nerd.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 MIME.
Web <URL:http://www.merlyn.demon.co.uk/> - FAQish topics, acronyms, & links.
Proper <= 4-line sig. separator as above, a line exactly "-- " (SonOfRFC1036)
Do not Mail News to me. Before a reply, quote with ">" or "> " (SonOfRFC1036)

Dr J R Stockton wrote:

In comp.lang.javascript message <1486365.uhbGJ8BuQJ (AT) PointedEars (DOT) de>,
Thu, 29 Oct 2009 19:50:30, Thomas 'PointedEars' Lahn
PointedEars (AT) web (DOT) de> posted:
Dr J R Stockton wrote:

Thomas 'PointedEars' Lahn posted:
Dr J R Stockton wrote:
Thomas 'PointedEars' Lahn posted:
Dr J R Stockton wrote:

[snip]

It's still annoying that one major browser lacks what others have (even
if out of fashion), especially if the functionality is present.
Which browser would that be?
With a little more - with any - humility and/or common sense, you would
read what you quote both before and after composing a reply. The answer
to that question is plainly visible above, currently at the >>>> level.
I have asked before because that implication of yours would be incorrect.
Firefox/Gecko does not lack what others have; IE/MSHTML does lack it. While
probably not in number of installations, `textContent' is the standards-
compliant approach which is supported by more current layout engines than
`innerText' is or is going to be.

Firefox apparently lacks what the most-used browser (MSIE), and three
other major PC browsers, have - innerText of iframe content.

The innerText property is a property of an Element. It is read/write
on most, but read only on a few elements.

<URL: http://msdn.microsoft.com/en-us/library/ms533899(VS.85).aspx >

Explains. You can disregard the garbage code by MSFT, which relies on
global scope pollution (element ID becomes globally accessible
property).

The DOM 3 Node textContent property:
http://www.w3.org/TR/DOM-Level-3-Core/core.html#Node3-textContent

Includes nodeValue when accessed from a CDATASection Node or Comment
Node (I haven't found need for that yet).

It is of course also a pity that IE lacks textContent - however, it is
unreasonable to expect (except in Nelson's context) Microsoft to heed
international standards.

MSFT decided not to implement textContent in IE8, for undisclosed

reasons.

https://connect.microsoft.com/IE/feedback/ViewFeedback.aspx?FeedbackID=334438
--
Garrett
comp.lang.javascript FAQ: http://jibbering.com/faq/

Dr J R Stockton wrote:

In comp.lang.javascript message <hccj1f$6u8$1 (AT) news (DOT) eternal-
september.org>, Thu, 29 Oct 2009 10:22:40, Garrett Smith
dhtmlkitchen (AT) gmail (DOT) com> posted:
Is this the issue I evaded?

As I stated, textContent is not related to the frame; stating
otherwise,
as the proposal for section (9.2) "9.2 How do I access a frame's
content?" would be misleading (counterproductive to FAQ goals).


If a user's browser shows an iframe element (called Fram), into which a
typical Web page has been loaded (e.g. by Fram.src=WebPage.htm), the
user sees something matching the meaning of the word "frame" on the OED;
and it contains visible material, some of which matches "text" in the
OED. The frame therefore contains text, and it is reasonable to ask
"How do I access a frame's content?", and therefore to have that as a
FAQ section Subject.

Text, in the OED sense, is commonly an important part of a frame's
content, and so the answer should include how to read it. The fact that
the frame element does not contain directly a method or property that
directly yields the text is irrelevant.

The "content" is part of the document. That "content" would be something
in that document. Once a reference to the document is obtained, the next
step is to get the content of that document. Possibly as:

fdoc,forms[0].elements["secret"].value;
fdoc.title;
fdoc.getElementById("pwd").value;
// one of:
fdoc.documentElement.textContent;
fdoc.documentElement.innerText;

fdoc.getElementsByTagName("script")[0].innerHTML;

For the question, the answer should address accessing the "JavaScript"
content AND the "HTML" content AND the "style" content.

Those things are more closely related to a Document. They would belong
under DOM and Forms. For example:

How can I read the text of an element?

Since all that is easy to do once one knows how, much of the answer can
readily be given as a series of examples with a little comment : for the
frame Fram -

COD = Fram.contentDocument
// Text :
BOD = COD.body
TXT = BOD.textContent || BOD.innerText // latter is needed for MSIE
// HTML :
HTM = BOD.innerHTML // ??
// Accoutrements :
ANK = COD.anchors ; LNK = COD.links ; // etc.
// JavaScript :
COW = Fram.contentWindow
VAR = COW.moo // Fram's JavaScript's var moo

Those are probably about right, but not directly tested; and a couple of
DOM methods could be shown.

Looks about right.

--
Garrett
comp.lang.javascript FAQ: http://jibbering.com/faq/

Dr J R Stockton wrote:

In effect, I want to read the file, HTML or TXT, as it exists on disc.

VK wrote:

You cannot do it for the reason explained at
http://groups.google.com/group/comp.lang.javascript/msg/d9f3f6724bada573

Dr J R Stockton wrote:

Unconvincing, because I *am* doing it,

VK wrote:

You don't, it is your delusion.
I don't know how and why are you doing it, but it was stated that "I
want to read the file, HTML or TXT, as it exists on disc." As long as
you are not using AJAX calls - and you don't - you are not able and
you are not reading any files "HTML or TXT, as it exists on disc" -
however wide the definition "as it exists on disc" would be taken.

Dr J R Stockton wrote:

Give or take irrelevant questions of character coding and newline
representation, I have been getting, by using innerHTML and by using
innerText, a string which agrees visually with the content of a TXT file
on disc, as would be shown by Notepad.

It should be expected in many (but not all) situations.
Contrary to the popular believe, browsers are *not* able to open text
or graphics files. What they are able to - as part of their extended
functionality - is to recognize some file types other than HTML and to
wrap them on the fly into predefined HTML templates so to display them
in the browser window. In the particular for text/plain files they are
using template
<HTML>
<HEAD></HEAD>
<BODY>
<PRE> text file content goes here </PRE>
</BODY>
</HTML>
with the exact tags' case (upper or lower) being browser dependent.
This way the text you "see" is in effect the content of a single <pre>
element necessarily altered from the "as it is on disc" to be placed
into this tag. For instance all less-than and greater-than signs will
be converted to the corresponding named HTML entities. The fact that
you were getting so far "by using innerHTML ..., a string which agrees
visually with the content of a TXT file" suggests that so far you were
lucky but not having any problematic characters in your .txt files,
otherwise see my post about NE (named entities) and NCR (numeric
character references) in HTML:
http://groups.google.com/group/comp.lang.javascript/msg/7a7cb7a5ca4ad387

I still WANT to read a HTML file correspondingly, seeing the source
lines as per Notepad; but I don't really NEED to, since what I can get
suffices for that part of the desired work that is NECESSARY.

The answer remains the same: in order to do so reliably and "as it is
on disk" and not as preprogrammed by this or that browser team, you
have to use XHR (aka AJAX, aka Ajax) and its responseText property
content. Any (i)frames are useless for the task and I hope I made it
clear why. It also solves your reading access synchronization problem,
because with XHR you will be prompted when the content is available or
prompted for the file access error.

VK wrote:

As much as I can understand you request, you want to get the textual
data from the loaded document in full and without omission which is
doable but it is a completely different task.

Dr J R Stockton wrote:

Yes, that is what I still WANT. *But it is more than, in the case of an
HTML page, I really NEED. *Therefore progress is being made.

The realization of the actual need and a proper description of this
need is a prerequisite step toward the satisfaction of the need, so
yes, an important progress is being made
The satisfaction way is already given a bit above.

Associated query : I have read a TXT file from disc, getting a matching
string. *It consists of many lines containing words separated by
punctuation. *They all start with the same sequence of words and
punctuation (improbably, zero length), but after that there is always
non-zero length. *No two lines completely agree. *What is the nicest way
of determining the common part AND obtaining in sequence strings for the
varying parts? *Think of it as like a representation of a directory
tree.

This is OT to the discussed FAQ topic but an interesting problem per
se. I am thinking to move it into separate thread or you may do it
yourself. I have a rather close request for ggNoSpam, in order to give
users an ability to adjust the regexp spam filter even with zero
knowledge of regular expressions. The abstract task description would
be:
"Given an array of strings with the minimum 2 and the maximum 1o
elements, find the shortest common word in these strings. If no such
common character sequence found, then try to find the biggest subset
of strings having a common word".

"word" is understood in regexp terms. To avoid "rush answers" with
common words like "a" or "the" articles let's define that the shortest
common word must be no shorter than 4 characters.


P.S. booh!

In comp.lang.javascript message <hcg0mb$cip$1 (AT) news (DOT) eternal-
september.org>, Fri, 30 Oct 2009 16:34:17, Garrett Smith
<dhtmlkitchen (AT) gmail (DOT) com> posted:

Dr J R Stockton wrote:

Firefox apparently lacks what the most-used browser (MSIE), and
three
other major PC browsers, have - innerText of iframe content.


The innerText property is a property of an Element. It is read/write
on most, but read only on a few elements.
...

You miss the point, and write irrelevancies. In the context of my
linxchek.htm function ReadDirectoryFile :-

IE works with innerText, but not with textContent.
FF works with textContent, but not with innerText.
Opera, Safari, and Chrome work with either.

It is a pity, and unexpected, that Firefox differs from IE and three
other well-known browsers.

It is a pity, but not unexpected, that IE differs from four other well-
known browsers.

And that is entirely independent of the standards, the mechanism, and
the reasons if any.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 MIME.
Web <URL:http://www.merlyn.demon.co.uk/> - FAQish topics, acronyms, & links.
Proper <= 4-line sig. separator as above, a line exactly "-- " (SonOfRFC1036)
Do not Mail News to me. Before a reply, quote with ">" or "> " (SonOfRFC1036)