www.webdeveloper.com
Results 1 to 4 of 4

Thread: Been involved in it too long....

  1. #1
    Join Date
    Dec 2005
    Posts
    2,984

    Been involved in it too long....

    I've been developing with jQuery for far too long. I have a simple, temporary one page site so, instead of loading jQuery, I am doing un-libraried Javascript. I just wanted to do some simple manipulations to a HTML5 video element.

    I started out with Javascripts basic DOM manipulation functions, but about a year ago I got involved in jQuery and I loved it...so today when I tried to do some basic DOM stuff, I was bewildered that I could barely do anything.

    I looped through the properties of elements returned by getElementById() or getElementsByTagName (in Chrome) and I saw only a couple of properties/methods, one was new to me - item() - can't recall seeing this before.

    Then I found out that, in Chrome, I need to use item() to return the actual DOM Object in order to manipulate it.

    Code:
    var poster = document.getElementById('video').getElementsByTagName('img');
    
    //this wouldn't work - yet it would a year or two ago...
    poster.style.display = 'none';
    
    //this would
    poster.item().style.display = 'none';
    I can't recall ever coming across this thing called item() before....what is it? Is it the standard nowadays?

    Thanks.
    I've switched careers...
    I'm NO LONGER a scientist,
    but now a web developer...
    awesome.

  2. #2
    Join Date
    Dec 2003
    Location
    Bucharest, ROMANIA
    Posts
    15,428
    Code:
    var poster = document.getElementById('video').getElementsByTagName('img')
    Simple. getElementsByTagName() returns always a DOM collection. not a single element. If you are dealing with more images, you should circle within a loop. same as in an array. That is what is actually written in the JQuery core code: a loop. Actually I am surprised that you don't know that.

    If you have a single element, well, of course it will be the first (and the only )

    Code:
    var poster = document.getElementById('video').getElementsByTagName('img')[0]
    Last edited by Kor; 03-11-2011 at 01:49 PM.

  3. #3
    Join Date
    Dec 2005
    Posts
    2,984
    Haha, thanks for that Kor...actually I did know that it was returned as an array....I just never used the item() method...I always did this way back when:

    Code:
    var img = document.getElementById('mydiv').getElementsByTagName('img');
    var items = img.length;
    for(i=0;i<items;i++) {
     //do stuff with img[0];
    }
    So basically it's always been a method...I just never used it before (and back then, never knew enough to use the following code snippet to find out its properties and methods)

    Code:
    for(i in collection) {
      console.log(i + ' ' + collection[i]);
    }
    Thank you, Kor, for (even very mildly) over estimating my intelligence.
    I've switched careers...
    I'm NO LONGER a scientist,
    but now a web developer...
    awesome.

  4. #4
    Join Date
    Dec 2003
    Location
    Bucharest, ROMANIA
    Posts
    15,428
    Quote Originally Posted by aj_nsc View Post
    var img = document.getElementById('mydiv').getElementsByTagName('img');
    var items = img.length;
    for(i=0;i<items;i++) {
    //do stuff with img[0];
    }
    Rather:
    Code:
    var images = document.getElementById('mydiv').getElementsByTagName('img'), img, i=0 ;
    while(img=images[i++]){
    // do something with img reference
    }
    Now you don't care whether the collection has 1, 2, 3 or n elements. Or none.

    I bet JQuery core has something like that inside. There is no other way. A language has its firm syntax. JQuery is nothing but JavaScript condensed and structured in a library. The base language should be the same
    Last edited by Kor; 03-11-2011 at 02:41 PM.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
HTML5 Development Center

"

"

X vBulletin 4.2.2 Debug Information

  • Page Generation 0.16267 seconds
  • Memory Usage 2,874KB
  • Queries Executed 15 (?)
More Information
Template Usage (34):
  • (1)SHOWTHREAD
  • (1)ad_footer_end
  • (1)ad_footer_start
  • (1)ad_global_above_footer
  • (1)ad_global_below_navbar
  • (1)ad_global_header1
  • (1)ad_global_header2
  • (1)ad_navbar_below
  • (1)ad_showthread_firstpost_sig
  • (1)ad_showthread_firstpost_start
  • (1)ad_thread_first_post_content
  • (1)ad_thread_last_post_content
  • (6)bbcode_code
  • (1)bbcode_quote
  • (1)footer
  • (1)forumjump
  • (1)forumrules
  • (1)gobutton
  • (1)header
  • (1)headinclude
  • (1)headinclude_bottom
  • (4)memberaction_dropdown
  • (1)navbar
  • (4)navbar_link
  • (1)navbar_moderation
  • (1)navbar_noticebit
  • (1)navbar_tabs
  • (2)option
  • (4)postbit
  • (4)postbit_onlinestatus
  • (4)postbit_wrapper
  • (1)spacer_close
  • (1)spacer_open
  • (1)tagbit_wrapper 

Phrase Groups Available (6):
  • global
  • inlinemod
  • postbit
  • posting
  • reputationlevel
  • showthread
Included Files (26):
  • ./showthread.php
  • ./global.php
  • ./includes/class_bootstrap.php
  • ./includes/init.php
  • ./includes/class_core.php
  • ./includes/config.php
  • ./includes/functions.php
  • ./includes/functions_navigation.php
  • ./includes/class_friendly_url.php
  • ./includes/class_hook.php
  • ./includes/class_bootstrap_framework.php
  • ./vb/vb.php
  • ./vb/phrase.php
  • ./includes/functions_facebook.php
  • ./includes/functions_calendar.php
  • ./includes/functions_bigthree.php
  • ./includes/class_postbit.php
  • ./includes/class_bbcode.php
  • ./includes/functions_reputation.php
  • ./includes/functions_notice.php
  • ./packages/vbattach/attach.php
  • ./vb/types.php
  • ./vb/cache.php
  • ./vb/cache/db.php
  • ./vb/cache/observer/db.php
  • ./vb/cache/observer.php 

Hooks Called (70):
  • init_startup
  • friendlyurl_resolve_class
  • init_startup_session_setup_start
  • database_pre_fetch_array
  • database_post_fetch_array
  • init_startup_session_setup_complete
  • global_bootstrap_init_start
  • global_bootstrap_init_complete
  • cache_permissions
  • fetch_threadinfo_query
  • fetch_threadinfo
  • fetch_foruminfo
  • load_show_variables
  • load_forum_show_variables
  • global_state_check
  • global_bootstrap_complete
  • global_start
  • style_fetch
  • global_setup_complete
  • showthread_start
  • showthread_getinfo
  • strip_bbcode
  • friendlyurl_clean_fragment
  • friendlyurl_geturl
  • forumjump
  • cache_templates
  • cache_templates_process
  • template_register_var
  • template_render_output
  • fetch_template_start
  • fetch_template_complete
  • parse_templates
  • fetch_musername
  • notices_check_start
  • notices_noticebit
  • process_templates_complete
  • friendlyurl_redirect_canonical
  • showthread_post_start
  • showthread_query_postids
  • showthread_query
  • bbcode_fetch_tags
  • bbcode_create
  • showthread_postbit_create
  • postbit_factory
  • postbit_display_start
  • bbcode_parse_start
  • postbit_imicons
  • bbcode_parse_complete_precache
  • bbcode_parse_complete
  • postbit_display_complete
  • memberaction_dropdown
  • tag_fetchbit_complete
  • forumrules
  • navbits
  • navbits_complete
  • build_navigation_data
  • build_navigation_array
  • check_navigation_permission
  • process_navigation_links_start
  • process_navigation_links_complete
  • set_navigation_menu_element
  • build_navigation_menudata
  • build_navigation_listdata
  • build_navigation_list
  • set_navigation_tab_main
  • set_navigation_tab_fallback
  • navigation_tab_complete
  • fb_like_button
  • showthread_complete
  • page_templates