How to ignore parent css style

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I'm wondering how to ignore a parent style and use the default style (none). I'll show my specific case as an example but I'm pretty sure this is a general question.

<style>
#elementId select {
    height:1em;
}
</style>

<div id="elementId">
    <select name="funTimes" style="" size="5">
        <option value="test1">fish</option>
        <option value="test2">eat</option>
        <option value="test3">cows</option>
    </select>
</div>

Ways I do not want to solve this problem:

  • I cannot edit the stylesheet where the "#elementId select" is set, my module won't have access that.
  • Preferably not override the height style using the style attribute.

For example using firebug i can turn off the parent style and all is well, this is the effect I am going for.

Once a style is set, can it be disabled or must it be overridden?

11 Answers

It must be overridden. You could use:

<!-- Add a class name to override -->
<select name="funTimes" class="funTimes" size="5">

#elementId select.funTimes {
   /* Override styles here */
}

Make sure you use !important flag in css style e.g. margin-top: 0px !important What does !important mean in CSS?

You could use an attribute selector, but since that isn't supported by legacy browsers (read IE6 etc), it's better to add a class name

This got bumped to the top because of an edit ... The answers have gotten a bit stale, and not as useful today as another solution has been added to the standard.

There is now an "all" shorthand property.

#elementId select.funTimes {
   all: initial;
}

This sets all css properties to their initial value ... note some of the initial values are inherit; Resulting in some formatting still taking place on the element.

Because of that pause required when reading the code or reviewing it in the future, don't use it unless you most as the review process is a point where errors/bugs can be made! when editing the page. But clearly if there are a large number of properties that need to be reset, then "all" is the way to go.

Standard is online here: https://drafts.csswg.org/css-cascade/#all-shorthand

you can create another definition lower in your CSS stylesheet that basically reverses the initial rule. you could also append "!important" to said rule to make sure it sticks.

The all property in CSS resets all of the selected element’s properties, except the direction and unicode-bidi properties that control text direction.

.module {
  all: unset;
}

The point of it is allowing for component-level resetting of styles. Sometimes it’s far easier to start from scratch with styling rather than fight against everything that is already there.

/* -------- For Your code -------- */
#elementId select.funTimes {
  all: unset;
}

It would make sense for CSS to have a way to simply add an additional style (in the head section of your page, for example, which would override the linked style sheet) such as this:

<head>
<style>
#elementId select {
    /* turn all styles off (no way to do this) */
}
</style>
</head>

and turn off all previously applied styles, but there is no way to do this. You will have to override the height attribute and set it to a new value in the head section of your pages.

<head>
<style>
#elementId select {
    height:1.5em;
}
</style>
</head>

There are a bunch of values that can be used to undo CSS rules: initial, unset & revert. More details from the CSS Working Group at W3C:

https://drafts.csswg.org/css-cascade/#defaulting-keywords

As this is 'draft' not all are fully supported, but unset and initial are in most major browsers, revert has less support.

Please see below typescript for re-applying css class again to an element to override parent container (usually a framework component) css styles and force your custom styles. Your app framework (be it angular/react, probably does this so the parent container css was re-applied and none of your expected effects in css-class-name is showing up for your child element. Call this.overrideParentCssRule(childElement, 'css-class-name'); to do what the framework just did (call this in document.ready or end of event handler):

      overrideParentCssRule(elem: HTMLElement, className: string) {
        let cssRules = this.getCSSStyle(className);
        for (let r: number = 0; r < cssRules.length; r++) {
          let rule: CSSStyleRule = cssRules[r];
          Object.keys(rule.style).forEach(s => {
            if (isNaN(Number(s)) && rule.style[s]) {
              elem.style[s] = rule.style[s];
            }
          });
        }
      }
  • Mike Zheng tradrejoe@gmail.com
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