Description
Fired before any page navigation action (an action that would result in a different page being displayed) takes place. The container may veto the action completely or specify a different URL to be navigated to, a different target FRAME, different text for an HTTP POST operation or additional HTTP headers.
Arguments
|
Name |
Type |
I/O |
Description |
|
URL |
String |
Both |
The URL of the page to be navigated to. |
|
NavFlags |
Long Integer |
In |
The OR of NavMasks constants specifying navigation options. |
|
Nhandle |
Long Integer |
In |
The ObjectHandle of the page providing the context for this navigation action. |
|
TargetName |
String |
Both |
The TARGET specification for this navigation. |
|
TextToPost |
String |
Both |
Text to include when using the HTTP POST method. |
|
ExtraHeaders |
String |
Out |
Additional HTTP headers to be issued with this navigation action. |
|
Cancel |
Boolean (by Reference) |
Out |
Leave False to allow this load to proceed, or set to True to veto loading of URL. |
The NavFlags argument is the OR of these NavMasks:
|
NavGet |
&H00000000 |
Uses the HTTP GET method. |
|
NavPost |
&H00000001 |
Uses the HTTP POST method. |
|
NavHead |
&H00000002 |
Uses the HTTP HEAD method. |
|
NavHiddenLoad |
&H00000004 |
This page will be loaded hidden. |
|
NavNoReadFromCache |
&H00000008 |
A fresh copy of this page will be loaded. |
|
NavPresentInCache |
&H00000010 |
This page is present in cache. |
|
NavInFrameContext |
&H00000020 |
This hyperlink originated in a FRAME page. |
|
NavFormSubmit |
&H00000040 |
This action originated in a user FORM submission. |
|
NavContainerAction |
&H00000080 |
This action was initiated by the container. |
|
NavPageBack |
&H00000100 |
This was a PageBack button action. |
|
NavPageForth |
&H00000200 |
This was a PageForth button action. |
|
NavDontMakeCurrent |
&H00000400 |
Page will be loaded to cache but not made current. |
|
NavMetaRefresh |
&H00000800 |
Action initiated by a META REFRESH. |
|
NavUserHyperlink |
&H00001000 |
Action initiated by a user hyperlink click. |
Remarks
Any navigation action triggers this event, whether user-initiated, requested by the container, or the expiration of a META REFRESH timeout period. User navigation actions include hyperlink clicks, form submissions, direct URL entry, file open requests and toolbar button presses which load new pages such as PageBack or Home.
If the page specified by URL is already cached then the NavPresentInCache bit will be set in NavFlags. The NavNoReadFromCache bit in NavFlags indicates that a fresh copy of the page will be loaded even if the page is present in cache.
The container can ignore this event and allow the navigation action to proceed, or veto the navigation action by setting Cancel to True. It can also allow the operation to proceed to a different URL by setting the URL argument to a new destination, change the value of TargetName to request a different target FRAME, modify the text to be posted (if this is a POST action) by changing TextToPost, or request issuance of extra HTTP headers via ExtraHeaders.