AddTag method

Adds HTML tag to be parsed. Only the tags added to the parser will be recognized. The other parts of the page is packed in plain/text nodes and treated as regular text. Thus the document model returned by the ParseString method contains only the parts of interest - explicitly specified through AddTag method.

Syntax:

parserobject.AddTag TagName, HasClosing, SelfNestingAllowed, _
              CopyContent, CannotContainOtherTags, _
              RequiredAttr, RequiredAttrValue

Parameters:

TagName - string, case insensetive. The tag name - for example "TITLE" or "BODY"

HasClosing - Boolean. If True the tag has a closing tag for example </TITLE>. If False the tag is assumed self-closing

SelfNestingAllowed - Boolean. Allow the tag to contain the same tags. E.g. <DIV> may contain other <DIV> tags (true). False means the content of the tag will not be searched for the contained tags of the same class - appropriate for the TITLE for example.

CopyContent - Boolean. If true the content of the tag will be placed in the "__content" item of the resulting node ( node("__content") will contain the text between <TAG> and </TAG>). This could be convenient if searching for data. Changing the "__content" item in the resulting node will NOT change the document regenerated by the GenerateDoc method! In most cases False should be used to lower the memory consumption.

CannotContainOtherTags - Boolean. Instructs the parser to not search the tag content for the other tags specified through other calls to the AddTag method.

RequiredAttr and RequiredAttrValue - Strings. If they are empty they are ignored. If the RequiredAttr is set to nonempty string than the tag is recognized only if it contains a HTML attribute with this name. If also RequiredAttrValue is not empty than also this attribute must be set to the value specified in order to recognize the tag. For example this technique is used by SCRIPT RUNAT=SERVER tags in the ASP pages. It could be useful for your own needs too - for example it is often useful to extract information from meta tags. All the META tags that have NAME attribute are typically related to the page content (contain keywords for example). Thus using these parameters you are able to request only META tags that have this attribute and ignore the others.

Samples:

parser.AddTag "META", False, False, False, True, "NAME", "Keywords"

Instructs the parser to strip the META tags that contain keywords

parser.AddTag "DIV", True, False, False, False, "DIVTYPE", "Advert"

Instructs the parser to strip the DIVisions with HTML attribute "DIVTYPE" set to "Advert". Suppose you will insert in them some rotating advertisements.

Remarks:

Using the TextEmbedParser makes possible to think for the HTML in way similar to the way script sees the page in the browser. But this is done on the server side. The object model is stripped to the tags you request - thus it is simplified.

The parser will not perform encoding or decoding of the content of the tags - e.g. &nbsp; (non breaking space) will appear "as is". When using a HTML as template decoding and encoding of the template are not very useful because the unchaged parts of the template are just copied or moved throughout the document tree. But when placing text/replacing template nodes the script may need to use the ASP's Server.HTMLEncode method. Decoding and encoding are also ambiguous because the parser strips only part of the HTML model and it cannot be sure what part of the unparsed test is a HTML code and what is text. In the rare cases when decoding of part of the template is required only the script may perform such operations based on some prior knowledge for the template structure. However such techniques are rarely needed when working with templates.