Accessing IMG Source Filename in IFRAME

mousebear

I need to find the filenames of a set of image files referenced in an HTML file, which is loaded in an IFRAME. I need to access it from the main page within which the IFRAME sits. The IMG tags reside within Anchor tags in the HTML file.

These filenames are going to be used to match the primary keys of some data in my MySQL DB.

Since the user gets to swap out the HTML files and a new set of images appear, I presume I need Javascript (client-side) to access these filenames.

I've gotten the following to work:

alert(document.frames('galleryFrame').document.images('thumb2').src);

There's the oddest thing though, This doesn't work unless I put the following line above it:

alert("hello");

Does anyone have an idea of what is going on here?

Thanks,

Ichiro

Is it a script generated iFrame and does it do what you report in all browsers or only IE?

Do you have some sample code or page one could look at?

mousebear

Thanks for responding. I only have IE to test it on. I am using IE7. It is not a script-generated IFRAME, just an IFRAME written into the HTML. I posted this about a week ago, so I've taken a different approach and gotten things working, but haven't been doing exactly what caused this behavior.

Here's one of the basic pages, without any of the javascript or PHP I am adding. It is the images inside INDEX.HTM inside the last IFRAME that I am trying to access.

http://clubs.ca4h.org/sanmateo/pacifica/projects/photography/photographyLauraWebber.html

Ichiro

Quick question, are you making sure the frame document is fully loaded before trying to access its contents?

If not, the quick answer is to use an onload event handler referenced in either the iFrame declaration itself, not so safe or better, the onload of the document being loaded which would then call the parent's image manipulation function?

By the way, and slightly off topic, if you have members of your 4H club whose projects are related to web design and html or even if you don't, you might want to consider validating your pages using the W3C validation service. Those pages are not very good examples of professional webmastering. ;-)

Another thing that is more on topic, you currently set the iFrame height to 100% but that won't make the iFrame height actually expand to fit its contents, you'll need a script in the parent called a script in the framed document called by the framed document's onload event handler. The framed document's script would measure the height of the document and then feed that to the parent's function which would then adjust the height of the iFrame to fit.

leatherback

mousebear wrote:
I only have IE to test it on. I am using IE7.

-- a bit off topic, but .. I just had to respond --

Please do yourself and everybody visiting your site a favor, and get at least firefox to test with as well. ie is not exactly a very good browser when it comes to interpreting layout and stuff. If you add firefox to your array, you will probably come across most of the oddities in the browsers

mousebear

I have solved all my problems, slowly but surely, related to accessing the .SRC file info. One thing I had to learn about was .contentWindow property. Turns out for one of my IFRAMES, I wasn't changing the .SRC attribute, so I couldn't access the HREF changes. However, I could access it using ....contentWindow.document.location.href (I can't remember if the .document part was in there or not, my code is at home). My current bit of troubleshooting is focused on calling a function from a function. For some reason the loop in the calling function stops when the called function does certain things. It also executes those things apparently in a weird order. I have bracketed a piece of code that changes the visibility of an object (ob.style.visibility = "hidden") by 2 alert statements. Both alerts show, then the objects go invisible! Then the calling function stops.

As for your off-topic issues: No offense taken. I wish our club had someone who knew something about websites, but they got me. I just thought I would help out, and soon found myself working way into the nights and weekends learning all this stuff through trial-by-error, google, and forums. I've only been at it a year now.

Yup, I'm sure my code is ugly. It seems like my code is only going to get improved, practically, through experience. You're seeing some of my first attempts. The problem is that I probably devote manyfold the time into our 4H club than any other volunteer because of the demands of this website. There are so many things we want to do with it. So much time seems to go into verifying that code will work on multiple browsers. I sort of resent that we live in a world where so much time is being wasted by so many people because these companies can't agree, but maybe this is the natural course of things. I do have someone looking into some of the compatibility issues for us, but they haven't gotten back to us yet. The W3C validation service sounds interesting. I had never heard of it before. Thanks for the 100% height tip. I have been avoiding getting Firefox, because of what that means in terms of committment, but I guess the sooner, the better. I'm glad you let me know that focusing on that browser will have the most bang for the buck. I did a lot of CAD customization in the old days, and that software all disappeared. It felt like time stolen from my life.

Ichiro

mousebear wrote:
I have solved all my problems

Cool!!

mousebear wrote:
My current bit of troubleshooting is focused on calling a function from a function. For some reason the loop in the calling function stops when the called function does certain things. It also executes those things apparently in a weird order. I have bracketed a piece of code that changes the visibility of an object (ob.style.visibility = "hidden") by 2 alert statements. Both alerts show, then the objects go invisible! Then the calling function stops.

Let me guess, Internet Explorer, right. We have got to get you hooked up with Firefox at some point. Instead of having to use alerts for trouble shooting, how would you like to be able to single step through the code while it is actually running?!?!?

That's not to say that getting things working in Firefox guarentees their working in IE but it sure helps speed things up so you can more quickly identify when it is truly a cross browser issue and not just borked code.

There are so many cool toys out there that are actually useful, for a change. When you get some time, let me know and I can give you what I consider the best resources available on the 'net. I also know a forum that has all the top names in web design that you definitely could benefit from joining. That does NOT mean that all the people there are the top names, my being there being proof of that.

mousebear wrote:
As for your off-topic issues: No offense taken. I wish our club had someone who knew something about websites, but they got me.

Ah, so you missed a meeting and attended the next one only to find out "you" had volunteered at the meeting you didn't attend?

That'll learn ya!

mousebear wrote:
,,,, and soon found myself working way into the nights and weekends learning all this stuff through trial-by-error, google, and forums. I've only been at it a year now.

I think most of us learn by trial and error although one reference you definitely need, if you haven't come accross it yet is "quirksmode"!!! Just add that text to any search you do and you will find THE best source for info on Javascript, among other things, available on the net. I use W3Schools to find out what the specifications are but I go to quirksmode to find out how they work in the real world!

mousebear wrote:
Yup, I'm sure my code is ugly. It seems like my code is only going to get improved, practically, through experience.

True, of course, although if you validate your code using some online validation service, such as the W3C provides or offline, using the Firefox plugin HTMLTidy, you will find you learn much faster because they show you exactly what is wrong and either tell you how to fix it or give you enough info so that you can go ask Professor Google and be reasonably sure of getting a good answer.

That doesn't mean that a perfectly valid page will not suck, as my sites are proof of but, I often find the cause of problems simply by validating the page and cleaning up any errors. It is such a simple tool to use and can sometimes save a lot of time that it definitely would be worth your while to look into using it.

And, while validation doesn't deal with Javascript at all, some javascript "errors" can have as their source, a problem in the construction of the page itself.

I'm no "Standardista" who is interested in validation for validation's sake or try to prove my l337||355 by putting validation logos on my pages but still, the validation tool is such a powerful tool that it is so easy to use that it is hard to pass it up.

One thing though, the sooner you start using it in a project the easier it is because fixing one or two errors at a time here or there is much easier than completing a project and trying to fix hundreds of errors.

mousebear wrote:
You're seeing some of my first attempts.

Not too terribly untolerable for just starting out! A bit advanced for someone just starting out, in my opinion though, so you seem to be on the right track. About the only thing I could say at this point, that I haven't already is that you seem to be falling into a bit of an 'iFrame-itis' trap at this point but the more important thing is to get a page working first, from which you can then evolve your techniques.

mousebear wrote:
The problem is that I probably devote manyfold the time into our 4H club than any other volunteer because of the demands of this website.

See, I told you you shouldn't have missed that meeting!

Considering that I probably spend 5 to 10 times the amount of time on private/personal projects as I do contracted projects, I must have a couple of million dollar sites out there by now.

But, what will likely get under your skin at some point, like cross browser compatiblity already has to a certain extent, are what I call "Weekend webbies". Kids with pirated copies of Photoshop and Dreamweaver that set themselves up as "Webmasters" and then throw a site together in a weekend or three and then calls it good enough. That's not to say that all younger people are guilty of this though as I have also seen a very dedicate and professional attitude in some that is far beyond their years.

Your attitude, displayed so far though strongly suggests you have what it takes to become a true professional. And, as you already seem to have a professional attitude towards things, you just need more experience, which so do we all.

mousebear wrote:
There are so many things we want to do with it. So much time seems to go into verifying that code will work on multiple browsers.

Welcome to the wonderful world of site construction. 😉 But, it gets easier over time. After a while you get so you know what works and what doesn't and it gets to the point where there end up only being minor, and sometimes comical errors as opposed to the big, rip it apart and start over errors that happen often when one first starts trying cross-browser support.

mousebear wrote:
I sort of resent that we live in a world where so much time is being wasted by so many people because these companies can't agree, but maybe this is the natural course of things.

You are right, it is the natural course of things but it can, as you already know, be VERY trying at times.

One thing to keep in mind though, some of the most powerful features in common use today originated from the source of what is arguably the worst browser in existence.

All in all, it's just something we all have to deal with and as my favorite saying goes, "If it was easy, everyone would be doing it!"

mousebear wrote:
I do have someone looking into some of the compatibility issues for us, but they haven't gotten back to us yet.

"Someone"?

Here is all you need to do it yourself,
1. A link to http://www.quirksmode.org/ and using the term "quirksmode" in all your web dev related searchs.
2. "VMWare" with a disk image of any flavor of Linux that strikes your fancy. There is a third OS that is good to test in as well but I have heard that it hasn't been licensed for use in virtual machines. 😉
3. A LOT of patience. 😃

mousebear wrote:
The W3C validation service sounds interesting. I had never heard of it before. Thanks for the 100% height tip. I have been avoiding getting Firefox, because of what that means in terms of committment, but I guess the sooner, the better. I'm glad you let me know that focusing on that browser will have the most bang for the buck. I did a lot of CAD customization in the old days, and that software all disappeared. It felt like time stolen from my life.

AutoCAD? Tell me about it! You would not believe the number of plugins and extensions I built for that only to have them all go to waste. Actually, any coding experience never truly goes to waste but I still like to complain.

http://validator.w3.org/ start validating pages as soon as possible because it is easier to fix a few here and there than have to wade in neck deep. It also helps immensely knowing you are starting out with clean html/css so that you can eliminate possible sources of problems.

But, "in terms of commitement"? You just don't want to accept that you are now a prisoner of teh Inter-tube, deal with it! 😃

One last thing, Laura Webber is one AMAZING photographer!! I haven't seen such a collection of such breathtaking photos from 5 different photographers let alone one! Here talent is simply amazing!

By the way, you can probably set this thread to "Resolved" at this point as it would seem that there is not much anyone can help you with specifically at this point. The oddness you still have in IE is likely something you will just have to figure out for yourself or, figure out if it is actually worth figuring out. 😉

Weedpacket

And at this moment, means, motive and opportunity have all coincided to allow me to attach this pic.

Ichiro

I hope you are happy with yourself Weekpacket!!! :mad:

I almost pissed myself laughing viewing that pie chart! 😃

So true! So very true!!

mousebear

Ah, what a flood of useful info. I wish I had received some of this a half year ago. Before that, I probably wouldn't have known what to do with it. We are way off topic, which is just fine for me, but probably not for anyone thinking they are viewing something about "Accessing IMG Source Filename in IFRAME ". Actually, I consider that RESOLVED, so I'll go with the flow here...

As for IFRAME's, I know it's considered a lesser way of doing things. I can't completely remember why I ended up doing that, but I'll see if I can figure out how to work with less of them in the future.

After riddling my code with ALERTS (thanks for letting me know there are debuggers that can make this job a lot easier), I found that my loop ... FOR (i=0; i<whatever.length; i++) was skipping 36 integers per pass. That's because the function I called from this function also had a loop using i as a counter. So now I have learned how javascript deals with local and global variables. My FOR loops now all have FOR (var i...), and I use VAR a lot more now so I don't get other unexpected behaviors.

I'll review all of your suggestions this weekend. It's a lot to digest and implement.

Are you really suggesting I load linux and other OS's on my machine? That scares me. But I'd like to know the possible benefits, vs. the time investment and risks.

I am not ever going to be a web professional. This is a volunteer effort, that has sort of gotten out of hand, but I do enjoy it, and it has been very valuable for our club. I am 2/3rds of the way through my real career that I am very happy with, that has nothing to do with computers, except in support of my work.

I don't feel the time I put into AutoCAD development as wasted, but where is all that McDonnel Douglas's GDS coding I did; to name just one of the many CAD software flavors we cycled through?

If you think our basic page is ugly, you are really going to hate the one I am attempting now, and the reason I joined this forum. This has been a very ambitious effort to link the photography galleries to professional and junior judging of these photos. The idea is that by judging your own, and others', photos (and by viewing critiques by others, including professional photographers of your work) you will develop a better feel for what makes a higher quality photograph. Which hopefully will translate into taking better photos.

Anyway, this means the scores and comments of each photo have to go into a MySQL database, and get retrieved. It's actually coming along OK so far, but I have not posted any data yet. Maybe I'll upload the page in the state it's in, just so people like yourself, who so graciously have taken an interest in my efforts, can put all these questions in context.

As I view topics in forums, I am put off by people that are blatantly asking for others to write their code for them. I am often surprised by the politeness of the replies. It has made me reluctant to ask questions until I have gone around in circles for a few hours. I figure I need to invest at least 2 hours of non-progress before imposing on the time of others.

God bless all those that give back to us that are just starting out...