To cite the use of this formal theory, please use Achim D. Brucker and Michael Herzberg. A Formal Model of the Document Object Model with Shadow Roots. In Archive of Formal Proofs, 2020. http://www.isa-afp.org/entries/Shadow_DOM.html, Formal proof development A BibTeX entry for LaTeX users is @Article{ brucker.ea:afp-shadow-dom:2020, author = {Achim D. Brucker and Michael Herzberg}, title = {Shadow DOM: A Formal Model of the Document Object Model with Shadow Roots}, journal = {Archive of Formal Proofs}, month = sep, year = 2020, date = {2020-09-28}, note = {\url{http://www.isa-afp.org/entries/Shadow_DOM.html}, Formal proof development}, issn = {2150-914x}, abstract = { In this AFP entry, we extend our formalization of the core DOM with \emph{Shadow Roots}. Shadow roots are a recent proposal of the web community to support a component-based development approach for client-side web applications. Shadow roots are a significant extension to the DOM standard and, as web standards are condemned to be backward compatible, such extensions often result in complex specification that may contain unwanted subtleties that can be detected by a formalization. Our Isabelle/HOL formalization is, in the sense of object-orientation, an extension of our formalization of the core DOM and enjoys the same basic properties, i.e., it is extensible, i.e., can be extended without the need of re-proving already proven properties and executable, i.e., we can generate executable code from our specification. We exploit the executability to show that our formalization complies to the official standard of the W3C, respectively, the WHATWG. }, public = {yes}, classification= {formal}, categories = {websecurity}, pdf = {http://www.brucker.ch/bibliography/download/2020/brucker.ea-afp-shadow-dom-2020.pdf}, filelabel = {Outline}, file = {http://www.brucker.ch/bibliography/download/2020/brucker.ea-afp-shadow-dom-outline-2020.pdf}, areas = {formal methods, security, software engineering}, url = {http://www.brucker.ch/bibliography/abstract/brucker.ea-afp-shadow-dom-2020} } An overview of the formalization is given in: Achim D. Brucker and Michael Herzberg. A Formally Verified Model of Web Components. In Formal Aspects of Component Software (FACS). Lecture Notes in Computer Science (12018), Springer-Verlag, 2020. http://www.brucker.ch/bibliography/abstract/brucker.ea-web-components-2019 A BibTeX entry for LaTeX users is @InCollection{ brucker.ea:web-components:2019, abstract = {The trend towards ever more complex client-side web applications is unstoppable. Compared to traditional software development, client-side web development lacks a well-established component model, i.e., a method for easily and safely reusing already developed functionality. To address this issue, the web community started to adopt shadow trees as part of the Document Object Model (DOM): shadow trees allow developers to "partition" a DOM instance into parts that should be safely separated, e.g., code modifying one part should not, unintentionally, affect other parts of the DOM. While shadow trees provide the technical basis for defining web components, the DOM standard neither defines the concept of web components nor specifies the safety properties that web components should guarantee. Consequently, the standard also does not discuss how or even if the methods for modifying the DOM respect component boundaries. In this paper, we present a formally verified model of web components and define safety properties which ensure that different web components can only interact with each other using well-defined interfaces. Moreover, our verification of the application programming interface (API) of the DOM revealed numerous invariants that implementations of the DOM API need to preserve to ensure the integrity of components.}, keywords = {Web Component, Shadow Tree, DOM, Isabelle/HOL}, location = {Amsterdam, The Netherlands}, author = {Achim D. Brucker and Michael Herzberg}, booktitle = {Formal Aspects of Component Software (FACS)}, language = {USenglish}, publisher = pub-springer, address = pub-springer:adr, series = s-lncs, number = 12018, isbn = {3-540-25109-X}, doi = {10.1007/978-3-030-40914-2_3}, editor = {Sung-Shik Jongmans and Farhad Arbab}, pdf = {http://www.brucker.ch/bibliography/download/2019/brucker.ea-web-components-2019.pdf}, title = {A Formally Verified Model of Web Components}, classification= {conference}, areas = {formal methods, software}, year = 2020, public = {yes}, url = {http://www.brucker.ch/bibliography/abstract/brucker.ea-web-components-2019} }