xref: /PHP-7.1/README.NEW-OUTPUT-API (revision 7f6387b5)
1$Id: README.NEW-OUTPUT-API 219039 2006-08-30 07:39:09Z mike $
2
3
4API adjustment to the old output control code:
5
6	Everything now resides beneath the php_output namespace,
7	and there's an API call for every output handler op.
8
9	Checking output control layers status:
10		// Using OG()
11		php_output_get_status();
12
13	Starting the default output handler:
14		// php_start_ob_buffer(NULL, 0, 1);
15		php_output_start_default();
16
17	Starting an user handler by zval:
18		// php_start_ob_buffer(zhandler, chunk_size, erase);
19		php_output_start_user(zhandler, chunk_size, flags);
20
21	Starting an internal handler whithout context:
22		// php_ob_set_internal_handler(my_php_output_handler_func_t, buffer_size, "output handler name", erase);
23		php_output_start_internal(handler_name, handler_name_len, my_php_output_handler_func_t, chunk_size, flags);
24
25	Starting an internal handler with context:
26		// not possible with old API
27		php_output_handler *h;
28		h = php_output_handler_create_internal(handler_name, handler_name_len, my_php_output_handler_context_func_t, chunk_size, flags);
29		php_output_handler_set_context(h, my_context, my_context_dtor);
30		php_output_handler_start(h);
31
32	Testing whether a certain output handler has already been started:
33		// php_ob_handler_used("output handler name");
34		php_output_handler_started(handler_name, handler_name_len);
35
36	Flushing one output buffer:
37		// php_end_ob_buffer(1, 1);
38		php_output_flush();
39
40	Flushing all output buffers:
41		// not possible with old API
42		php_output_flush_all();
43
44	Cleaning one output buffer:
45		// php_ob_end_buffer(0, 1);
46		php_output_clean();
47
48	Cleaning all output buffers:
49		// not possible with old API
50		php_output_clean_all();
51
52	Discarding one output buffer:
53		// php_ob_end_buffer(0, 0);
54		php_output_discard();
55
56	Discarding all output buffers:
57		// php_ob_end_buffers(0);
58		php_output_discard_all();
59
60	Stopping (and dropping) one output buffer:
61		// php_ob_end_buffer(1, 0)
62		php_output_end();
63
64	Stopping (and dropping) all output buffers:
65		// php_ob_end_buffers(1, 0);
66		php_output_end_all();
67
68	Retrieving output buffers contents:
69		// php_ob_get_buffer(zstring);
70		php_output_get_contents(zstring);
71
72	Retrieving output buffers length:
73		// php_ob_get_length(zlength);
74		php_output_get_length(zlength);
75
76	Retrieving output buffering level:
77		// OG(nesting_level);
78		php_output_get_level();
79
80	Issue a warning because of an output handler conflict:
81		// php_ob_init_conflict("to be started handler name", "to be tested if already started handler name");
82		php_output_handler_conflict(new_handler_name, new_handler_name_len, set_handler_name, set_handler_name_len);
83
84	Registering a conflict checking function, which will be checked prior starting the handler:
85		// not possible with old API, unless hardcoding into output.c
86		php_output_handler_conflict_register(handler_name, handler_name_len, my_php_output_handler_conflict_check_t);
87
88	Registering a reverse conflict checking function, which will be checked prior starting the specified foreign handler:
89		// not possible with old API
90		php_output_handler_reverse_conflict_register(foreign_handler_name, foreign_handler_name_len, my_php_output_handler_conflict_check_t);
91
92	Facilitating a context from within an output handler callable with ob_start():
93		// not possible with old API
94		php_output_handler_hook(PHP_OUTPUT_HANDLER_HOOK_GET_OPAQ, (void *) &custom_ctx_ptr_ptr);
95
96	Disabling of the output handler by itself:
97		//not possible with old API
98		php_output_handler_hook(PHP_OUTPUT_HANDLER_HOOK_DISABLE, NULL);
99
100	Marking an output handler immutable by itself because of irreversibility of its operation:
101		// not possible with old API
102		php_output_handler_hook(PHP_OUTPUT_HANDLER_HOOK_IMMUTABLE, NULL);
103
104	Restarting the output handler because of a CLEAN operation:
105		// not possible with old API
106		if (flags & PHP_OUTPUT_HANDLER_CLEAN) { ... }
107
108	Recognizing by the output handler itself if it gets discarded:
109		// not possible with old API
110		if ((flags & PHP_OUTPUT_HANDLER_CLEAN) && (flags & PHP_OUTPUT_HANDLER_FINAL)) { ... }
111
112
113Output handler hooks
114
115	The output handler can change its abilities at runtime. Eg. the gz handler can
116	remove the CLEANABLE and REMOVABLE bits when the first output has passed through it;
117	or handlers implemented in C to be used with ob_start() can contain a non-global
118	context:
119		PHP_OUTPUT_HANDLER_HOOK_GET_OPAQ
120			pass a void*** pointer as second arg to receive the address of a pointer
121			pointer to the opaque field of the output handler context
122		PHP_OUTPUT_HANDLER_HOOK_GET_FLAGS
123			pass a int* pointer as second arg to receive the flags set for the output handler
124		PHP_OUTPUT_HANDLER_HOOK_GET_LEVEL
125			pass a int* pointer as second arg to receive the level of this output handler
126			(starts with 0)
127		PHP_OUTPUT_HANDLER_HOOK_IMMUTABLE
128			the second arg is ignored; marks the output handler to be neither cleanable
129			nor removable
130		PHP_OUTPUT_HANDLER_HOOK_DISABLE
131			the second arg is ignored; marks the output handler as disabled
132
133
134Open questions
135
136	Should the userland API be adjusted and unified?
137
138	Many bits of the manual (and very first implementation) do not comply
139	with the behaviour of the current (to be obsoleted) code, thus should
140	the manual or the behaviour be adjusted?
141
142END
143