Work with library items

A library is a special Dreamweaver file containing a collection of individual assets or copies of assets that you can place in your web pages. The assets in a library are called library items. Items that you can store in a library include images, tables, sounds, and files created with Adobe Flash. You can automatically update all the pages that use a library item whenever you edit the item.

For example, suppose you’re building a large site for a company that wants a slogan to appear on every page. You can create a library item to contain the slogan and use that library item on every page. If the slogan changes, you can change the library item and automatically update every page that uses it.

Dreamweaver stores library items in a Library folder within the local root folder for each site. Each site has its own library.

You can create a library item from any element in the body section of a document, including text, tables, forms, Java applets, plug‑ins, ActiveX elements, navigation bars, and images.

For linked items such as images, the library stores only a reference to the item. The original file must remain at the specified location for the library item to work correctly.

It can still be useful to store an image in a library item, though. For example, you could store a complete img tag in a library item, which would allow you to easily change the image’s alt text, or even its src attribute, throughout the site. (Don’t use this technique to change an image’s width and height attributes, though, unless you also use an image editor to change the actual size of the image.)

When you use a library item, Dreamweaver inserts a link to it, rather than the item itself, in the web page. That is, Dreamweaver inserts a copy of the HTML source code for that item into the document and adds an HTML comment containing a reference to the original, external item. It is this external reference that makes automatic updating possible.

When you create a library item that includes an element with a Dreamweaver behavior attached to it, Dreamweaver copies the element and its event handler (the attribute that specifies which event triggers the action, such as onClick, onLoad, or onMouseOver, and which action to call when the event occurs) to the library item file. Dreamweaver does not copy the associated JavaScript functions into the library item. Instead, when you insert the library item into a document, Dreamweaver automatically inserts the appropriate JavaScript functions into the head section of that document (if they aren’t already there).

There are special requirements for editing the behaviors in library items. Library items cannot contain style sheets, because the code for those elements is part of the head section.

When you add a library item to a page, the actual content is inserted in the document along with a reference to the library item.

When you edit a library item, you can update all documents that use that item. If you choose not to update, the documents remain associated with the library item; you can update them later.

You can rename items to break their connection with documents or templates, delete items from the site’s library, and recreate a missing library item.

When you delete a library item, Dreamweaver removes it from the library but doesn’t change the contents of any documents that use the item.

You can customize the highlight color of library items and show or hide highlighting by setting Highlighting preferences.

You can use the Property inspector to open a library item for editing, detach a selected library item from its source file, or overwrite an item with the currently selected library item.

If you’ve added a library item to your document and you want to edit the item specifically for that page, you must break the link between the item in the document and the library. Once you’ve made an instance of a library item editable, that instance isn’t updated when the library item changes.

To edit a behavior in a library item, you must first insert the item in a document, then make the item editable in that document. After you’ve made the changes, you can re-create the library item, replacing the item in the library with the edited item from your document.