Generating high volume accessible documents
An architecture for generating accessible documents uses a Data/Layout Description Language (D/LDL) and data sources. The D/LDL and the data source are fed to a pre-processing module which generates an intermediate document containing all the data and positioning hints and structural information required to create the accessible file. The intermediate file is converted into an object model using a Model Builder and is passed to a Model Formatter to calculate the exact positioning of elements. The object model is then passed to a Standard formatter to ensure compliance with required standards and is then passed to a model writer which translates the object to an accessible file in the required format. The design allows for skipping the preprocessing module if the full file is available and allows to plug different model writers for different formats.
1. A method for generating a presentation file comprising:
(a) accessing a layout file, the layout file using a Data/Layout Description Language (D/LDL) comprising positioning information and accessibility information with placeholders for variable data, from one or more different data sources, including at least one of a database, different file formats and user provided variable data;
(b) populating the layout file with data obtained from the one or more different data sources;
(c) automatically converting the populated layout file to an object model-that-serves as an abstraction layer between the D/LDL and an accessibility standard-compliant document format;
(d) calculating the positions of elements within the object model that flow within tables or across pages;
(e) adding accessibility related information to the object model; and
(f) converting the object model to the accessibility standard-compliant document format.
2. The method of claim 1 wherein converting (f) comprises converting the object model to a selected one of plurality of different accessibility standard-compliant document formats.
3. The method of claim 2 wherein one of the plurality of different accessibility standard-compliant document formats comprises a portable document format (PDF).
4. The method of claim 2 wherein one of the plurality of different accessibility standard-compliant document formats comprises hypertext markup language (HTML).
5. The method of claim 2 wherein one of the plurality of different accessibility standard-compliant document formats comprises markup language.
6. The method of claim 1 wherein the adding comprises creating dynamic entities including tables of content, indices and running headers or footers based on headings including calculating the positions of elements in and corresponding links for the tables of content and the indices.
7. An apparatus for generating a presentation file comprising:
at least one processor configured to execute instructions stored in non-transitory memory, the processor executing instructions to perform operations comprising:
(a) accessing a layout file, the layout file using a Data/Layout Description Language (D/LDL) comprising positioning information and accessibility information with placeholders for variable data from different data sources including at least one of a database, file formats and user-provided variable data,
(b) populating the layout file with data obtained from the one or more different data sources;
(c) automatically converting the populated layout file to an object model having a format that is independent of a format of the populated layout file, the object model serving as an abstraction layer between the D/LDL and an accessibility standard-compliant document format;
(d) calculating the positions of elements within the object model that flow within tables or across pages;
(e) adding accessibility related information to the object model; and
(f) converting the object model to an accessibility standard-compliant document format.
8. The apparatus of claim 1 converting comprises converting the object model to a selected one of a plurality of different accessibility standard-compliant document formats.
9. The apparatus of claim 2 wherein one of the plural different accessibility standard-compliant document formats comprises portable document format (PDF).
10. The apparatus of claim 2 wherein one of the plural different accessibility standard-compliant document formats comprises hypertext markup language (HTML).
11. The apparatus of claim 2 wherein one of the plural different accessibility standard-compliant document formats comprises markup language.
12. The apparatus of claim 1 wherein the adding comprises (i) creating dynamic entities including tables of content and indices and (ii) calculating the positions of elements in and corresponding links for the tables of content and the indices.
13. The apparatus of claim 7 wherein at least one processor is configured to allow changes in a format used to specify the D/LDL file without changing position formatting and accessibility formatting.
14. The apparatus of claim 7 wherein the at least one processor is further configured to calculate the position of every element taking into account page size, number of columns, column width, table cell width and other attributes specified in the D/LDL.
15. The apparatus of claim 7 wherein the at least one processor is further configured to calculate accessibility attributes comprising header IDs assigned to every table cell.
16. The method of claim 1 further including allowing changes in a format used to specify the D/LDL file without changing position formatting and accessibility formatting.
17. The method of claim 1 further including calculating position of every element taking into account page size, number of columns, column width, table cell width and other attributes specified in the D/LDL.
18. The method of claim 1 further including calculating accessibility attributes comprising header IDs assigned to every table cell.