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Focus first text field using jQuery

When it comes to focus the first text field on a page using jQuery , the usual solution would be:

PLAIN TEXT
JavaScript:
  1. $(“:text:visible:enabled:eq(0)”).focus();

This query means to find the first of input text field(s), which is/are visible and enabled. However, this would also extract text field(s) which is/are under a display:none parent(s). So a more complete way would be:

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JavaScript:
  1. $(“:text:visible:enabled”).filter(function(){
  2.      return $(this).parents(“:hidden”).size()==0;
  3.  }).slice(0,1).focus();

The filter here would try to determine if the text field is a descendant of a hidden ancestor. The usage of slice(0,1) instead of get(0) is to keep the chainability. A test page is put up here .

Finally, you may wrap it up with a plugin:

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JavaScript:
  1. (function($){
  2.     $.fn.focusFirstField = function(){
  3.         $this = this;
  4.         $this.find(“:text:visible:enabled”).filter(function(){
  5.             return $(this).parents(“:hidden”).size() == 0;
  6.         }).slice(0,1).focus();
  7.         return this;
  8.     }
  9. })(jQuery)

So that you can do this:

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JavaScript:
  1. $(“#form1,#form2”).focusFirstField(); //form1 or form2 may be ‘hidden’ dynamically

I just wonder if there is any ‘selector-only’ solution for this?

Update: It turns out that the child’s visiblity would override parent’s visibility. So the filter should only check display none:

PLAIN TEXT
JavaScript:
  1. $(":text:visible:enabled").filter(function(){
  2.      return $(this).parents.filter(function(){
  3.          return this.style.display == "none"; })
  4.     .size()==0;
  5.  }).slice(0,1).focus();

I’ve updated the demo page .


“Focus first text field using jQuery” - 7 個回應

  1. gr 小影 說:

    用 prototype 的話我會這樣：

    
 Event.observe(window, 'load', function() {
	try{
		($$('form')[0]).focusFirstElement();
	} catch (e) {}
 });

    ( 在page load 完後才 focus )

    發表於 14-Apr-08 9:23 am | 永久連結

  2. gr 小影 說:

    呃… 上面 [ 0 ] 變了 [0]

    發表於 14-Apr-08 9:24 am | 永久連結

  3. gr Jacky 說:

    Can this function handle when
    1) style=“display:none” on the input?
    2) the form itself is under a div with display:none?

    發表於 14-Apr-08 9:46 am | 永久連結

  4. gr anonymous 說:

    Why slice() instead of eq()?

    http://docs.jquery.com/Core/eq#position

    發表於 14-Apr-08 10:34 am | 永久連結

  5. gr 小影 說: 
    
  findFirstElement: function(form) {
    var elements = $(form).getElements().findAll(function(element) {
      return 'hidden' != element.type && !element.disabled;
    });
    var firstByIndex = elements.findAll(function(element) {
      return element.hasAttribute('tabIndex') && element.tabIndex >= 0;
    }).sortBy(function(element) { return element.tabIndex }).first();
    return firstByIndex ? firstByIndex : elements.find(function(element) {
      return ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
    });
  },
  focusFirstElement: function(form) {
    form = $(form);
    form.findFirstElement().activate();
    return form;
  }

    form 或 form 上層的 elements 是 hidden … 是不行的

    發表於 14-Apr-08 10:42 am | 永久連結

  6. gr Jacky 說:

    anonymous: yes, can use eq() also.

    小影: that’s my interest… multiple forms, which may be ‘hidden’

    發表於 14-Apr-08 11:39 am | 永久連結

  7. gr Jacky 說:

    BTW, eq() also uses slice()

    發表於 14-Apr-08 12:21 pm | 永久連結

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