1 / 18

Hypertext and E-Commerce

Hypertext and E-Commerce. Informatics 211 November 6, 2007. The Basics of Hypertext. The concept: interrelated information Content (the information) Structure (the links between the information) View (what part of the content and structure one sees at a given moment). Content.

avilasandra
Download Presentation

Hypertext and E-Commerce

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hypertext and E-Commerce Informatics 211 November 6, 2007

  2. The Basics of Hypertext • The concept: interrelated information • Content (the information) • Structure (the links between the information) • View (what part of the content and structure one sees at a given moment)

  3. Content • Homogeneous or heterogeneous? • Homogeneity gives lots of scope for storage mechanisms, optimizations, complex queries, … • Heterogeneity is what makes hypertext useful, and different from databases • The subtle notion of “objects”

  4. Structure • Links • Implicit, computed, explicit • Anchors • On what? The “object”? Part of the object? What about dynamic objects? Only certain types of objects? • Links on links. Or rather, links between anchors on links?

  5. View and Interactivity : where the user is at runtime, interacting with the information • Distinguishing content and structure • Distinguishing views of objects from the objects. • Anchors on the views, rather than the objects • Traversal, context, the hypertext state machine • What does a link mean? • The assumption of "take me there and show me" • How many users are there? • Who is the user? Hypertext and automated analyses

  6. Architecture • Where's the data? Who controls it? Who can change it? Who can see it? • Where are the links? • Who controls the viewing? • Who controls the state transitions?

  7. Classic systems • KMS, Notecards, Hypercard • Chapter 5 from Jakob Nielsen's book Multimedia and Hypertext: The Internet and Beyond, Morgan Kaufmann Publishers, 1995. • http://www.useit.com/papers/hypertext_theory/

  8. Open Hypertext: bringing hypertext to other applications • Open: • link to external applications (and data that they control) • link from external applications? • First-class links and the link base • n-ary links

  9. Chimera example

  10. Chimera Architecture

  11. Dynamic links & content • Links whose existence are determined at run time • Database driven queries • Content cobbled together

  12. Architecture • data not under a single authority regime • viewing not under a single regime • what about the link base?

  13. The World Wide Web • Naming the information • Heterogeneous sources, and hence a communication protocol • Architecture • client-server • Roy’s dissertation defense slides

  14. Hybrid Approaches • Chimera 2.0

  15. Bridge to Andre’s Talk • WebDAV: an extension to the HTTP/1.1 protocol to support • Distributed • Authoring And • Versioning • But have to wait until we’ve covered the background (at least)

  16. REST Principles • 1. The key abstraction of information is a resource, named by an URL. • 2. The representation of a resource is a sequence of bytes, plus representation metadata to describe those bytes. • 3. All interactions are context-free. • 4. Only a few primitive operations are available. • 5. Idempotent operations and representation metadata are encouraged in support of caching. • 6. The presence of intermediaries is promoted.

  17. Insights on the Web • Separation of representation from resource (cf. node/object in hypertext) • Tolerance of inconsistency • Broken links • Unintelligible representations • Best effort processing • Decentralization and network effects • URIs as plain text

  18. E-Commerce • The demands of financial security • The demands of the user experience • Session IDs: maintaining pointers to an individual across time • Shopping carts • The demands of an extensive set of offerings • Dynamic page construction • The example of Amazon.com

More Related