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○ Ensure proper limits are in place on the maximum amount of memory that the XML processing engine
can use, the amount of nested entities that the XML code can have, and the maximum length of entity
names, attribute names, and so on. This practice helps prevent the triggering of potential issues.
9.2.4 Writing Server-Side JavaScript Applications
SAP HANA Extended Application Services (SAP HANA XS) supports server-side application programming in
JavaScript. The server-side application you develop can use a collection of JavaScript APIs to expose authorized
data to client requests, for example, to be consumed by a client GUI such as a Web browser including SAPUI5
applications and mobile clients.
Since JavaScript programs are stored in the SAP HANA repository, the steps in this task description assume that
you have already created a workspace and a project (of type XS Project), and that you have shared the project
with other members of the development team. To write a server-side JavaScript application, you must perform
the following high-level steps.
1. Create a root package for your application, for example, helloxsjs.
2. Create an application descriptor for your application and place it in the root package you created in the
previous step.
The application descriptor is the core file that you use to describe an application's availability within SAP
HANA Extended Application Services. The application-descriptor file has no contents and no name; it only has
the file extension .xsapp.
Note: For backward compatibility, content is allowed in the .xsapp file but ignored.
3. Create an application-access file and place it in the package to which you want to grant access.
The application-access file does not have a name; it only has the file extension .xsaccess. The contents of
the .xsaccess file must be formatted according to JavaScript Object Notation (JSON) rules and associated
with the package the file belongs to. The rules defined in the .xsaccess file apply to the package it resides in
as well as any subpackages lower in the package hierarchy.
4. If you used the authorization keyword in the application-access file (.xsaccess) file for your application,
create an application-privileges file for the application and define the application privileges.
The application-privileges file does not have a name; it only has the file extension .xsprivileges. The
contents of the .xsprivileges file must be formatted according to JavaScript Object Notation (JSON)
rules. Multiple .xsprivileges files are allowed, but only at different levels in the package hierarchy; you
cannot place two .xsprivileges files in the same application package. The privileges defined in
a .xsprivileges file are bound to the package to which the file belongs and can only be applied to this
package and its subpackages.
Note: The .xsprivileges file lists the authorization levels available for granting to an application
package; the .xsaccess file defines which authorization level is assigned to which application
package.
5. Create the server-side JavaScript files that contain the application logic.
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You can use the available JavaScript APIs (for example, the database or request-processing API) to expose
authorized data to client requests.
P U B L I C
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SAP HANA Developer Guide
Writing Server-Side JavaScript Applications