METHOD AND DEVICE FOR CASCADING STYLE SHEET (CSS) SELECTOR MATCHING

• US 20120173967A1
• Filed: 12/29/2011
• Published: 07/05/2012
• Est. Priority Date: 12/30/2010
• Status: Active Grant

• Current Assignee: Opera Software ASA
• Original Assignee: Opera Software ASA
• Inventors: LILLESVEEN, Rune
• Granted Patent: US 9,805,009 B2
• Time in Patent Office: Days
• US Class Current: 715/235
• CPC Class Codes: G06F 16/9577 Optimising the visualization of content, e.g. distillation of HTML documents
• CPC Class Codes: G06F 16/958 Organisation or management of web site content, e.g. publishing, maintaining pages or automatic linking
• CPC Class Codes: G06F 40/103 Formatting, i.e. changing of presentation of documents automatic justification G06F40/189; automatic line break hyphenation G06F40/191
• CPC Class Codes: G06F 40/117 Tagging; Marking up details of markup languages G06F40/143; Designating a block; Setting of attributes style sheets, e.g. eXtensible Stylesheet Language Transformation [XSLT], G06F40/154
• CPC Class Codes: G06F 40/143 Markup, e.g. Standard Generalized Markup Language [SGML] or Document Type Definition [DTD]
• CPC Class Codes: G06F 40/154 Tree transformation for tree-structured or markup documents, e.g. XSLT, XSL-FO or stylesheets
• CPC Class Codes: G06F 40/166 Editing, e.g. inserting or deleting

Abstract

The present invention relates to a computer-implemented method for Cascading Style Sheet (CSS) selector matching. The method comprises: generating machine code based on text which includes at least one CSS selector; and executing the machine code to perform the CSS selector matching.

The present invention also relates to a corresponding computer device and a computer readable storage medium.

Claims

1. A method for Cascading Style Sheet (CSS) selector matching, which method comprises:

generating machine code based on text which includes at least one CSS selector; and

executing the machine code to perform the CSS selector matching.

2. A method according to claim 1, wherein executing the machine code to perform the CSS selector matching comprises or is comprised in:

invoking the machine code for a given CSS selector and a given Document Object Model (DOM) node or element.

3. A method according to claim 1, wherein the machine code is generated directly from the text which includes at least one CSS selector.

4. A method according to claim 1, wherein generating machine code based on the text which includes at least one CSS selector comprises:

parsing the text which includes at least one CSS selector into a data structure representing the at least one CSS selector; and

compiling the data structure into the machine code.

5. A method according to claim 4, wherein the data structure is a byte-code or an Abstract Syntax Tree (AST).

6. A method according to claim 4, wherein the data structure is compiled into the machine code using Just In Time (JIT) compilation.

7. A method according to claim 4, wherein the text includes several CSS selectors, and wherein only some selectors are compiled based on use of the selectors.

8. A method according to claims 2,

wherein generating machine code based on the text which includes at least one CSS selector comprises:

parsing the text which includes at least one CSS selector into a data structure representing the at least one CSS selector; and

compiling the data structure into the machine code, and

wherein parsing the text which includes at least one CSS selector into a data structure representing the at least one CSS selector comprises;

translating each simple constituent of the text which includes at least one CSS selector into one or more byte-code instructions; and

translating combinators of the text which includes at least one CSS selector into control flow instructions and instructions for picking candidate nodes or elements from the DOM for matching.

9. A method according to claim 4, further comprising:

executing or interpreting the data structure to perform the CSS selector matching.

10. A computer device for CSS selector matching, which device comprises:

means for generating machine code based on text which includes at least one CSS selector; and

an execution engine adapted to execute the machine code to perform the CSS selector matching.

11. A computer device according to claim 10, wherein said means comprises a generator adapted to generate machine code directly based on text which includes at least one CSS selector

12. A computer device according to claim 10, wherein said means comprises:

a CSS parser adapted to parse the text which includes at least one CSS selector into a data structure representing the at least one CSS selector, such as a byte-code or an AST; and

a compiler adapted to compiling the data structure into machine code for the particular architecture of the computer device,

wherein the execution engine is adapted to invoke the machine code for a given CSS selector and a given DOM node or element.

13. A computer readable storage medium having code or instructions, which code or instructions when executed on a computer cause(s) a process that includes:

generating machine code based on text which includes at least one CSS selector; and

executing the machine code to perform CSS selector matching.

14. (canceled)