dojo.hasAttr

since:V1.2

Contents

• dojo.hasAttr
  • Introduction
  • Usage
  • Examples
  • See also

Checks a node for the presence of an attribute.

Introduction

dojo.hasAttr() is a companion function for dojo.attr. It checks if an attribute is present on a DOM node, and returns the truthy value if it is there, and falsy value otherwise.

Since 1.4 it will return true for standard properties that can’t have a corresponding attribute, e.g., innerHTML or class.

Since Dojo 1.7, dojo.hasAttr is exposed via the has method of the dojo/dom-attr module. An alias is kept in dojo/_base/html for backward-compatibility.

Usage

// Dojo 1.7+ (AMD)
require(["dojo/dom-attr"], function(domAttr){
  result = domAttr.has(node, attr);
});

// Dojo < 1.7
result = dojo.hasAttr(node, attr);

// Dojo 1.7+ (AMD) require(["dojo/dom-attr"], function(domAttr){ result = domAttr.has(node, attr); }); // Dojo < 1.7 result = dojo.hasAttr(node, attr);

node

id or reference of the DOM node to get/set style for

attr

the attribute property name.

result

truthy, if the attribute is present, falsy otherwise

Examples

Dojo 1.7+ (AMD)

When using AMD format in a fully baseless application, has is accessed from the dojo/dom-attr module.

require(["dojo/dom-attr"], function(domAttr){
  domAttr.has("nodeId", "foo");
});

require(["dojo/dom-attr"], function(domAttr){ domAttr.has("nodeId", "foo"); });

Alternatively, you can load dojo base in AMD style and continue using dojo.hasAttr in the define or require callback:

require(["dojo"], function(dojo){
  dojo.hasAttr("nodeId", "foo");
});

require(["dojo"], function(dojo){ dojo.hasAttr("nodeId", "foo"); });

Dojo < 1.7

dojo.hasAttr("nodeId", "foo");

dojo.hasAttr("nodeId", "foo");

Testing for attributes

The following example will check for several attributes.

function checkAttributes(){
  showAttribute("id");
  showAttribute("type");
  showAttribute("name");
  showAttribute("innerHTML");
  showAttribute("foo");
  showAttribute("baz");
}
function showAttribute(name){
  var result = dojo.hasAttr("model", name);
  // I don't use dojo.create() here because it was not available in 1.2
  var wrapper = dojo.doc.createElement("div");
  dojo.place(wrapper, "out");
  wrapper.innerHTML = "<input type='checkbox' disabled='disabled' " +
    (result ? "checked='checked'" : "") + "> has " + name;
}

function checkAttributes(){ showAttribute("id"); showAttribute("type"); showAttribute("name"); showAttribute("innerHTML"); showAttribute("foo"); showAttribute("baz"); } function showAttribute(name){ var result = dojo.hasAttr("model", name); // I don't use dojo.create() here because it was not available in 1.2 var wrapper = dojo.doc.createElement("div"); dojo.place(wrapper, "out"); wrapper.innerHTML = "<input type='checkbox' disabled='disabled' " + (result ? "checked='checked'" : "") + "> has " + name; }

<p><input id="model" name="model" baz="foo"> &mdash; our model node</p>
<p><button onclick="checkAttributes();">Check attributes</button></p>
<p id="out"></p>

<p><input id="model" name="model" baz="foo"> &mdash; our model node</p> <p><button onclick="checkAttributes();">Check attributes</button></p> <p id="out"></p>

See also

DOM operations:

• dojo.attr
• dojo.getNodeProp
• dojo.getAttr
• dojo.setAttr
• dojo.removeAttr
• dojo.style

NodeList:

• dojo.NodeList
• dojo.NodeList.attr
• dojo.NodeList.removeAttr

External links:

• DOM Attributes and The Dojo Toolkit 1.2

Table of Contents

• dojo.hasAttr
  • Introduction
  • Usage
  • Examples
    • Dojo 1.7+ (AMD)
    • Dojo < 1.7
    • Testing for attributes
  • See also