2.3.5 WML data value properties
In addition to NMTOKEN type data, the other three WML data must be defined in text form, i.e., quotation marks. The question we are concerned about is, what data values can these types of data represent? Or, what is the nature of the data values they represent?
In fact, WML data can only be length (Length), macro variable (Vdata), stream (Flow), inline (Inline), layout (Layout), text (Text), hyperchain (Href), Boolean, data (Number), or enhanced mode (Emphasis).
2.3.6 Cards and Card Sets
When we analyzed the structure of WML programs, we will talk about the information of WML documents being organized in the form of card sets and card sets. A Deck is a collection of one or more cards. After the client terminal issues a request, WML sends the Deck from the network to the client's browser, and the Deck is the smallest unit of information sent by the server. After the user's browser receives the Deck, he can browse all the cards included. Card is used to represent or describe one or more user interaction units.
2.3.7 Card Set Template
The same card set usually contains many cards, and the definitions, attributes, or formats of these cards are usually similar. If we define each card one by one, it will obviously be very troublesome. To this end, WML provides the function of a card set template. A series of standards and parameters are defined in the template, which can be applied to all cards of the same card set, thereby greatly improving our programming efficiency. We will introduce the content about card set templates later.
2.3.8 WML and URL and program block anchor points
We know that Global Network WWW is a network of various information and devices. In order to ensure global interaction, people have formulated three specifications: First, the unified resource locator URL provides standard naming and positioning methods for all network resources; second, standard protocols, such as HTTP protocol, provide transmission methods for WWW resources; third. Standard content types, such as HTML and WML, provide content forms and standards for WWW resources. WML follows these specifications and expands the scope of URL usage. In WML, not only the hyperconnection, file path and file name can be processed as URLs, but card names, macro variable names and various internal resource names can also be processed as URLs.
To this end, WML has improved the way HTML naming resource locations and uses program anchors (Fragment Anchor) to handle the status of a certain program in a WML program. The anchor points of the program block are defined according to the WML rules of the document and are written in a way that the tic toe is added (#) before the program block symbol. Using block anchors, WML programs can locate different cards in the same card set. If the program segment is not specified in the program, the URL name referenced in the program refers to the entire card group, and the name of the card group is also the name of the first card in the card group. 2.3.9 Browser operation history
In order to manage the execution of WML programs on the browser side, WML uses the function of "browser front and back relationship" to save the execution status of WML programs and various parameters, variables, etc., so that it can be used to record the user's operation status. At the same time, WML also provides a simple navigation history model, which records various actions when users browse in the form of URL addresses, and puts these URL addresses into the history push stack. By pushing the stack, users can realize the resurgence of historical browsing and other operations.
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