Microsoft Developer Network

Allows authors to disable the bidirectional algorithm for selected fragments of text.

Members Table

The following table lists the members exposed by the bdo object.

Attributes/Properties

Show: Attributes/Properties Behaviors Collections Events Filters Methods Objects Styles

Attribute Property Description ACCESSKEY accessKey Sets or retrieves the accelerator key for the object. ariaBusy   Sets or retrieves the busy state of this element. ariaChecked   Sets or retrieves the checked state of this element. ariaDisabled   Sets or retrieves the disabled state of this element. ariaExpanded   Sets or retrieves the expanded state of this element. ariaHaspopup   Sets or retrieves a value indicating whether this element may display a pop-up window. ariaHidden   Sets or retrieves the hidden state of this element. ariaInvalid   Sets or retrieves the invalid state of this element. ariaLevel   Sets or retrieves the level of this element. ariaMultiselect   Sets or retrieves the multiple-selection state of this element. ariaPosinset   Sets or retrieves the current position of an item within a set. ariaPressed   Sets or retrieves the pressed state of a button that can be toggled. ariaReadonly   Sets or retrieves the read-only state of this element. ariaRequired   Sets or retrieves the form-completion requirement of this element. ariaSecret   Sets or retrieves the secret state of this element. ariaSelected   Sets or retrieves the selection state of this element. ariaSetsize   Sets or retrieves the set size of this element. ATOMICSELECTION Specifies whether the element and its contents must be selected as a whole, indivisible unit. attributes   Retrieves a collection of attributes of the object. canHaveChildren Gets a value indicating whether the object can contain child objects. canHaveHTML Sets or retrieves the value indicating whether the object can contain rich HTML markup. CLASS className Sets or retrieves the class of the object. clientHeight Retrieves the height of the object including padding, but not including margin, border, or scroll bar. clientLeft Retrieves the distance between the offsetLeft property and the true left side of the client area. clientTop Retrieves the distance between the offsetTop property and the true top of the client area. clientWidth Retrieves the width of the object including padding, but not including margin, border, or scroll bar. CONTENTEDITABLE contentEditable Sets or retrieves the string that indicates whether the user can edit the content of the object. DIR dir Sets or retrieves the reading order of the object. firstChild Retrieves a reference to the first child in the childNodes collection of the object. HIDEFOCUS hideFocus Sets or gets the value that indicates whether the object visibly shows that it has focus. ID id Retrieves the string identifying the object. innerHTML Sets or retrieves the HTML between the start and end tags of the object. innerText Sets or retrieves the text between the start and end tags of the object. isContentEditable Gets the value that indicates whether the user can edit the contents of the object. isDisabled Gets the value that indicates whether the user can interact with the object. isMultiLine Retrieves the value indicating whether the content of the object contains one or more lines. isTextEdit Retrieves whether a TextRange object can be created using the object. LANG lang Sets or retrieves the language to use. LANGUAGE language Sets or retrieves the language in which the current script is written. lastChild Retrieves a reference to the last child in the childNodes collection of an object. nextSibling Retrieves a reference to the next child of the parent for the object. nodeName Retrieves the name of a particular type of node. nodeType Retrieves the type of the requested node. nodeValue Sets or retrieves the value of a node. offsetHeight Retrieves the height of the object relative to the layout or coordinate parent, as specified by the offsetParent property. offsetLeft Retrieves the calculated left position of the object relative to the layout or coordinate parent, as specified by the offsetParent property. offsetParent Retrieves a reference to the container object that defines the offsetTop and offsetLeft properties of the object. offsetTop Retrieves the calculated top position of the object relative to the layout or coordinate parent, as specified by the offsetParent property. offsetWidth Retrieves the width of the object relative to the layout or coordinate parent, as specified by the offsetParent property. outerHTML Sets or retrieves the object and its content in HTML. outerText Sets or retrieves the text of the object. ownerDocument Retrieves the document object associated with the node. parentElement Retrieves the parent object in the object hierarchy. parentNode Retrieves the parent object in the document hierarchy. parentTextEdit Retrieves the container object in the document hierarchy that can be used to create a TextRange containing the original object. previousSibling Retrieves a reference to the previous child of the parent for the object. readyState Retrieves the current state of the object. role   Sets or retrieves the role for this element. scopeName Gets the namespace defined for the element. scrollHeight Retrieves the scrolling height of the object. scrollLeft Sets or retrieves the distance between the left edge of the object and the leftmost portion of the content currently visible in the window. scrollTop Sets or retrieves the distance between the top of the object and the topmost portion of the content currently visible in the window. scrollWidth Retrieves the scrolling width of the object. sourceIndex Retrieves the ordinal position of the object, in source order, as the object appears in the document's all collection. TABINDEX tabIndex Sets or retrieves the index that defines the tab order for the object. tagName Retrieves the tag name of the object. tagUrn Sets or gets the Uniform Resource Name (URN) specified in the namespace declaration. TITLE title Sets or retrieves advisory information (a ToolTip) for the object. UNSELECTABLE Specifies that an element cannot be selected. Behavior Description clientCaps Provides information about features supported by Internet Explorer, as well as a way for installing browser components on demand. download Downloads a file and notifies a specified callback function when the download is complete. homePage Contains information about a user's homepage. Collection Description all Returns a reference to the collection of elements contained by the object. attributes Retrieves a collection of attributes of the object. childNodes Retrieves a collection of HTML Elements and TextNode objects that are direct descendants of the specified object. children Retrieves a collection of DHTML Objects that are direct descendants of the object. filters Retrieves the collection of filters that have been applied to the object. Event Description onactivate Fires when the object is set as the active element. onafterupdate Fires on a databound object after successfully updating the associated data in the data source object. onbeforeactivate Fires immediately before the object is set as the active element. onbeforecopy Fires on the source object before the selection is copied to the system clipboard. onbeforecut Fires on the source object before the selection is deleted from the document. onbeforedeactivate Fires immediately before the activeElement is changed from the current object to another object in the parent document. onbeforeeditfocus Fires before an object contained in an editable element enters a UI-activated state or when an editable container object is control selected. onbeforepaste Fires on the target object before the selection is pasted from the system clipboard to the document. onbeforeupdate Fires on a databound object before updating the associated data in the data source object. onblur Fires when the object loses the input focus. oncellchange Fires when data changes in the data provider. onclick Fires when the user clicks the left mouse button on the object. oncontextmenu Fires when the user clicks the right mouse button in the client area, opening the context menu. oncontrolselect Fires when the user is about to make a control selection of the object. oncopy Fires on the source element when the user copies the object or selection, adding it to the system clipboard. oncut Fires on the source element when the object or selection is removed from the document and added to the system clipboard. ondblclick Fires when the user double-clicks the object. ondeactivate Fires when the activeElement is changed from the current object to another object in the parent document. ondrag Fires on the source object continuously during a drag operation. ondragend Fires on the source object when the user releases the mouse at the close of a drag operation. ondragenter Fires on the target element when the user drags the object to a valid drop target. ondragleave Fires on the target object when the user moves the mouse out of a valid drop target during a drag operation. ondragover Fires on the target element continuously while the user drags the object over a valid drop target. ondragstart Fires on the source object when the user starts to drag a text selection or selected object. ondrop Fires on the target object when the mouse button is released during a drag-and-drop operation. onerrorupdate Fires on a databound object when an error occurs while updating the associated data in the data source object. onfilterchange Fires when a visual filter changes state or completes a transition. onfocus Fires when the object receives focus. onfocusin Fires for an element just prior to setting focus on that element. onfocusout Fires for the current element with focus immediately after moving focus to another element. onhelp Fires when the user presses the F1 key while the browser is the active window. onkeydown Fires when the user presses a key. onkeypress Fires when the user presses an alphanumeric key. onkeyup Fires when the user releases a key. onlosecapture Fires when the object loses the mouse capture. onmousedown Fires when the user clicks the object with either mouse button. onmouseenter Fires when the user moves the mouse pointer into the object. onmouseleave Fires when the user moves the mouse pointer outside the boundaries of the object. onmousemove Fires when the user moves the mouse over the object. onmouseout Fires when the user moves the mouse pointer outside the boundaries of the object. onmouseover Fires when the user moves the mouse pointer into the object. onmouseup Fires when the user releases a mouse button while the mouse is over the object. onmousewheel Fires when the wheel button is rotated. onmove Fires when the object moves. onmoveend Fires when the object stops moving. onmovestart Fires when the object starts to move. onpaste Fires on the target object when the user pastes data, transferring the data from the system clipboard to the document. onpropertychange Fires when a property changes on the object. onreadystatechange Fires when the state of the object has changed. onresizeend Fires when the user finishes changing the dimensions of the object in a control selection. onresizestart Fires when the user begins to change the dimensions of the object in a control selection. onscroll Fires when the user repositions the scroll box in the scroll bar on the object. onselectstart Fires when the object is being selected. Filter property Description Alpha Adjusts the opacity of the content of the object. AlphaImageLoader Displays an image within the boundaries of the object and between the object background and content, with options to clip or resize the image. When loading a Portable Network Graphics (PNG) image, tranparency—from zero to 100 percent—is supported. Barn Reveals new content of the object with a motion that resembles doors opening or closing. BasicImage Adjusts the color processing, image rotation, or opacity of the content of the object. BlendTrans Reveals new content of the object by fading the original content. Blinds Reveals new content of the object with a motion that appears to open or close blinds. Blur Blurs the content of the object so that it appears out of focus. CheckerBoard Reveals new content of the object by uncovering squares placed like a checkerboard over the original content. Chroma Displays a specific color of the content of the object as transparent. Compositor Displays new content of the object as a logical color combination of the new and original content. The color and alpha values of each version of the content are evaluated to determine the final color on the output image. DropShadow Creates a solid silhouette of the content of the object, offset in the specified direction. This creates the illusion that the content is floating and casting a shadow. Emboss Displays the content of the object as an embossed texture using grayscale values. Engrave Displays the content of the object as an engraved texture using grayscale values. Fade Reveals new content of the object by fading out the original content. FlipH Displays the content of the object flipped across the horizontal axis. FlipV Displays the content of the object flipped across the vertical axis. Glow Adds radiance around the outside edges of the content of the object so that it appears to glow. Gradient Displays a colored surface between the object's background and content. GradientWipe Reveals new content of the object by passing a gradient band over the original content. Gray Displays the content of the object in grayscale. ICMFilter Converts the color content of the object based on an Image Color Management (ICM) profile. This enables improved display of specific content, or simulated display for hardware devices, such as printers or monitors. Inset Reveals new content of the object diagonally. Invert Reverses the hue, saturation, and brightness values of the content of the object. Iris Reveals new content of the object with an iris effect, similar to the opening of a camera aperture. Light Creates the effect of a light shining on the content of the object. MaskFilter Displays transparent pixels of the object content as a color mask, and makes the nontransparent pixels transparent. Matrix Resizes, rotates, or reverses the content of the object using matrix transformation. MotionBlur Causes the content of the object to appear to be in motion. Pixelate Displays the content of the object as colored squares that take the average color value of the pixels they replace. This filtered display can be used as a transition. RadialWipe Reveals new content of the object with a radial wipe, like a windshield-wiper blade. RandomBars Reveals new content of the object by exposing random lines of pixels. RandomDissolve Reveals new content of the object by exposing random pixels. Redirect Not currently supported. RevealTrans Reveals new content of the object using one of 24 predefined Transition effects. Shadow Creates a solid silhouette of the content of the object, offset in the specified direction. This creates the illusion of a shadow. Slide Reveals new content of the object by sliding sections of the image into place. Spiral Reveals new content of the object with a spiral motion. Stretch Reveals new content of the object with a stretching motion to cover the original content. One option resembles a cube rotating from one face to another. Strips Reveals new content of the object by moving successive strips into place, like a diagonal saw blade passing across the original content. Wave Performs a sine wave distortion of the content of the object along the vertical axis. Wheel Reveals new content of the object with a rotating motion, like spokes of a wheel covering the original content. Xray Changes the color depth of the content of the object and displays it in black and white. Zigzag Reveals new content of the object with a forward and back motion that moves down the object. Method Description appendChild Appends an element as a child to the object. applyElement Makes the element either a child or parent of another element. blur Causes the element to lose focus and fires the onblur event. clearAttributes Removes all attributes and values from the object. cloneNode Copies a reference to the object from the document hierarchy. componentFromPoint Returns the component located at the specified coordinates via certain events. fireEvent Fires a specified event on the object. focus Causes the element to receive the focus and executes the code specified by the onfocus event. getAdjacentText Returns the adjacent text string. getAttribute   Retrieves the value of the specified attribute. getAttributeNode Gets an attribute object referenced by the attribute.name property. getElementsByTagName Retrieves a collection of objects based on the specified element name. getExpression Retrieves the expression for the given property. hasAttribute   Determines whether an attribute with the specified name exists. hasChildNodes Returns a value that indicates whether the object has children. insertAdjacentElement Inserts an element at the specified location. insertBefore Inserts an element into the document hierarchy as a child node of a parent object. mergeAttributes Copies all read/write attributes to the specified element. normalize Merges adjacent TextNode objects to produce a normalized document object model. removeAttribute   Removes the given attribute from the object. removeAttributeNode Removes an attribute object from the object. removeChild Removes a child node from the object. removeExpression Removes the expression from the specified property. removeNode Removes the object from the document hierarchy. replaceAdjacentText Replaces the text adjacent to the element. replaceChild Replaces an existing child element with a new child element. replaceNode Replaces the object with another element. setActive Sets the object as active without setting focus to the object. setAttribute   Sets the value of the specified attribute. setAttributeNode Sets an attribute object node as part of the object. setExpression Sets an expression for the specified object. swapNode Exchanges the location of two objects in the document hierarchy. Object Description currentStyle Represents the cascaded format and style of the object as specified by global style sheets, inline styles, and HTML attributes. Style attribute Style property Description ACCELERATOR accelerator Sets or retrieves a string that indicates whether the object contains an accelerator key. border border Sets or retrieves the properties to draw around the object. border-bottom borderBottom Sets or retrieves the properties of the bottom border of the object. border-bottom-color borderBottomColor Sets or retrieves the color of the bottom border of the object. border-bottom-style borderBottomStyle Sets or retrieves the style of the bottom border of the object. border-bottom-width borderBottomWidth Sets or retrieves the width of the bottom border of the object. border-color borderColor Sets or retrieves the border color of the object. border-left borderLeft Sets or retrieves the properties of the left border of the object. border-left-color borderLeftColor Sets or retrieves the color of the left border of the object. border-left-style borderLeftStyle Sets or retrieves the style of the left border of the object. border-left-width borderLeftWidth Sets or retrieves the width of the left border of the object. border-right borderRight Sets or retrieves the properties of the right border of the object. border-right-color borderRightColor Sets or retrieves the color of the right border of the object. border-right-style borderRightStyle Sets or retrieves the style of the right border of the object. border-right-width borderRightWidth Sets or retrieves the width of the right border of the object. border-style borderStyle Sets or retrieves the style of the left, right, top, and bottom borders of the object. border-top borderTop Sets or retrieves the properties of the top border of the object. border-top-color borderTopColor Sets or retrieves the color of the top border of the object. border-top-style borderTopStyle Sets or retrieves the style of the top border of the object. border-top-width borderTopWidth Sets or retrieves the width of the top border of the object. border-width borderWidth Sets or retrieves the width of the left, right, top, and bottom borders of the object. clip clip Sets or retrieves which part of a positioned object is visible. direction direction Sets or retrieves the reading order of the object. display display Sets or retrieves whether the object is rendered. filter filter Sets or retrieves the filter or collection of filters applied to the object. hasLayout Gets a value that indicates whether the object has layout. height height Sets or retrieves the height of the object. layout-grid layoutGrid Sets or retrieves the composite document grid properties that specify the layout of text characters. layout-grid-mode layoutGridMode Sets or retrieves whether the text layout grid uses two dimensions. margin margin Sets or retrieves the width of the top, right, bottom, and left margins of the object. margin-bottom marginBottom Sets or retrieves the height of the bottom margin of the object. margin-left marginLeft Sets or retrieves the width of the left margin of the object. margin-right marginRight Sets or retrieves the width of the right margin of the object. margin-top marginTop Sets or retrieves the height of the top margin of the object. max-height maxHeight Sets or retrieves the maximum height for an element. max-width maxWidth Sets or retrieves the maximum width for an element. min-height minHeight Sets or retrieves the minimum height for an element. min-width minWidth Sets or retrieves the minimum width for an element. outline   outline Sets or retrieves the color, style, and width of the outline frame. outline-color   outlineColor Sets or retrieves the color of the outline frame. outline-style   outlineStyle Sets or retrieves the style of the outline frame. outline-width   outlineWidth Sets or retrieves the width of the outline frame. overflow overflow Sets or retrieves a value indicating how to manage the content of the object when the content exceeds the height or width of the object. overflow-x overflowX Sets or retrieves how to manage the content of the object when the content exceeds the width of the object. overflow-y overflowY Sets or retrieves how to manage the content of the object when the content exceeds the height of the object. padding padding Sets or retrieves the amount of space to insert between the object and its margin or, if there is a border, between the object and its border. padding-bottom paddingBottom Sets or retrieves the amount of space to insert between the bottom border of the object and the content. padding-left paddingLeft Sets or retrieves the amount of space to insert between the left border of the object and the content. padding-right paddingRight Sets or retrieves the amount of space to insert between the right border of the object and the content. padding-top paddingTop Sets or retrieves the amount of space to insert between the top border of the object and the content. position position Sets or retrieves the type of positioning used for the object. scrollbar-3dlight-color scrollbar3dLightColor Sets or retrieves the color of the top and left edges of the scroll box and scroll arrows of a scroll bar. scrollbar-arrow-color scrollbarArrowColor Sets or retrieves the color of the arrow elements of a scroll arrow. scrollbar-base-color scrollbarBaseColor Sets or retrieves the color of the main elements of a scroll bar, which include the scroll box, track, and scroll arrows. scrollbar-darkshadow-color scrollbarDarkShadowColor Sets or retrieves the color of the gutter of a scroll bar. scrollbar-face-color scrollbarFaceColor Sets or retrieves the color of the scroll box and scroll arrows of a scroll bar. scrollbar-highlight-color scrollbarHighlightColor Sets or retrieves the color of the top and left edges of the scroll box and scroll arrows of a scroll bar. scrollbar-shadow-color scrollbarShadowColor Sets or retrieves the color of the bottom and right edges of the scroll box and scroll arrows of a scroll bar. scrollbar-track-color scrollbarTrackColor Sets or retrieves the color of the track element of a scroll bar. text-autospace textAutospace Sets or retrieves the autospacing and narrow space width adjustment of text. text-overflow textOverflow Sets or retrieves a value that indicates whether to render ellipses(...) to indicate text overflow. text-underline-position textUnderlinePosition Sets or retrieves the position of the underline decoration that is set through the textDecoration property of the object. unicode-bidi unicodeBidi Sets or retrieves the level of embedding with respect to the bidirectional algorithm. white-space whiteSpace Sets or retrieves a value that indicates whether lines are automatically broken inside the object. width width Sets or retrieves the width of the object. word-wrap wordWrap Sets or retrieves whether to break words when the content exceeds the boundaries of its container. zoom zoom Sets or retrieves the magnification scale of the object.

Remarks

The BDO element can be used to control the reading order of a block of text.

The Unicode bidirectional algorithm automatically reverses embedded character sequences according to their inherent direction. For example, the base direction of an English document is left-to-right (ltr). If portions of a paragraph within this document contain a language with the right-to-left (rtl) reading order, you can reverse the direction of that language by applying the bidirectional algorithm.

The bidirectional algorithm and the DIR attribute generally suffice for embedded direction changes. However, incorrect presentations can occur when you expose formatted text to the bidirectional algorithm. For example, a paragraph containing English and Hebrew that is formatted for e-mail could be incorrectly inverted by the bidirectional algorithm. Because the reading order of the Hebrew text was inverted once for the e-mail, exposing it to the bidirectional algorithm would invert the words a second time.

The BDO element turns off the algorithm and controls the reading order. The DIR attribute is required when you use the BDO element.

This element is available in HTML and script as of Microsoft Internet Explorer 5.

This element is an inline element.

This element requires a closing tag.

Example

This example uses the BDO element to correct the reading order of a block of text.

The following string includes text written in the left-to-right order of the English language and the right-to-left order of Hebrew: This fragment is in English, WERBEH NI SI TNEMGARF SIHT.

Assume that the right-to-left text (WERBEH NI SI TNEMGARF SIHT.) already has been inverted, so that it displays in the correct direction. If you subsequently apply the Unicode bidirectional to the text, the text inverts a second time and incorrectly displays as left-to-right instead of right-to-left.

The solution is to override the bidirectional algorithm and put the block of text in the correct reading order inside a BDO element whose DIR attribute is set to ltr.

<BDO DIR="ltr">This fragment is in English, 
    WERBEH NI SI TNEMGARF SIHT.</BDO>

Standards Information

This object is defined in HTML 4.0 .

See Also

direction