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LIBXO(3) Library Functions Manual LIBXO(3) NAME xo_open_list, xo_open_list_h, xo_open_list_hd, xo_open_list_d xo_open_instance, xo_open_instance_h, xo_open_instance_hd, xo_open_instance_d xo_close_instance, xo_close_instance_h, xo_close_instance_hd, xo_close_instance_d xo_close_list, xo_close_list_h, xo_close_list_hd, xo_close_list_d -- open and close lists and instances LIBRARY library "libxo" SYNOPSIS #include <libxo/xo.h> int xo_open_list_h(xo_handle_t *xop, const char *name); int xo_open_list(const char *name); int xo_open_list_hd(xo_handle_t *xop, const char *name); int xo_open_list_d(const char *name); int xo_open_instance_h(xo_handle_t *xop, const char *name); int xo_open_instance(const char *name); int xo_open_instance_hd(xo_handle_t *xop, const char *name); int xo_open_instance_d(const char *name); int xo_close_instance_h(xo_handle_t *xop, const char *name); int xo_close_instance(const char *name); int xo_close_instance_hd(xo_handle_t *xop); int xo_close_instance_d(void); int xo_close_list_h(xo_handle_t *xop, const char *name); int xo_close_list(const char *name); int xo_close_list_hd(xo_handle_t *xop); int xo_close_list_d(void); DESCRIPTION Lists are sequences of instances of homogeneous data objects. Two dis- tinct levels of calls are needed to represent them in our output styles. Calls must be made to open and close a list, and for each in- stance of data in that list, calls must be make to open and close that instance. The name given to all calls must be identical, and it is strongly sug- gested that the name be singular, not plural, as a matter of style and usage expectations. A list is a set of one or more instances that appear under the same parent. The instances contain details about a specific object. One can think of instances as objects or records. A call is needed to open and close the list, while a distinct call is needed to open and close each instance of the list: xo_open_list("item"); for (ip = list; ip->i_title; ip++) { xo_open_instance("item"); xo_emit("{L:Item} '{:name/%s}':0, ip->i_title); xo_close_instance("item"); } xo_close_list("item"); Getting the list and instance calls correct is critical to the proper generation of XML and JSON data. EXAMPLE: xo_open_list("user"); for (i = 0; i < num_users; i++) { xo_open_instance("user"); xo_emit("{k:name}:{:uid/%u}:{:gid/%u}:{:home}0, pw[i].pw_name, pw[i].pw_uid, pw[i].pw_gid, pw[i].pw_dir); xo_close_instance("user"); } xo_close_list("user"); TEXT: phil:1001:1001:/home/phil pallavi:1002:1002:/home/pallavi XML: <user> <name>phil</name> <uid>1001</uid> <gid>1001</gid> <home>/home/phil</home> </user> <user> <name>pallavi</name> <uid>1002</uid> <gid>1002</gid> <home>/home/pallavi</home> </user> JSON: user: [ { "name": "phil", "uid": 1001, "gid": 1001, "home": "/home/phil", }, { "name": "pallavi", "uid": 1002, "gid": 1002, "home": "/home/pallavi", } ] LEAF LISTS In contrast to a list of instances, a "leaf list" is list of simple values. To emit a leaf list, call the xo_emit() function using the ""l"" modifier: for (ip = list; ip->i_title; ip++) { xo_emit("{Lwc:Item}{l:item}0, ip->i_title); } The name of the field must match the name of the leaf list. In JSON, leaf lists are rendered as arrays of values. In XML, they are rendered as multiple leaf elements. JSON: "item": "hammer", "nail" XML: <item>hammer</item> <item>nail</item> SEE ALSO xo_emit(3), libxo(3) ADDITIONAL DOCUMENTATION FreeBSD uses libxo version 0.6.1. Complete documentation can be found on github: http://juniper.github.io/libxo/0.6.1/libxo-manual.html libxo lives on github as: https://github.com/Juniper/libxo The latest release of libxo is available at: https://github.com/Juniper/libxo/releases HISTORY The libxo library was added in FreeBSD 11.0. AUTHOR Phil Shafer FreeBSD ports 15.0 December 4, 2014 LIBXO(3)
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | LEAF LISTS | SEE ALSO | ADDITIONAL DOCUMENTATION | HISTORY | AUTHOR
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