Update docs and prepare QPDF::writeJSON for changes

Add additional parameters that will be needed to call QPDF::writeJSON
in partial mode.

TODO

@@ -69,24 +69,9 @@ Soon: Break ground on "Document-level work"
 JSON v2 fixes
 =============
 
-* Get rid of separate format for --json and --json-output. Instead,
-  --json-output can just require an outfile and change some defaults
-  like which keys are present and json-stream-data. This makes it
-  easier to support use cases like being able to use information in
-  other top-level keys ("pages", "attachments", etc.) to drive
-  modifications made to objects without having to run qpdf twice. I
-  think --json-output should make the default key be only "qpdf" and
-  the default json-stream-data mode be inline, but make it so you can
-  use --json-stream-data and --json-stream-prefix with --json and
-  --json-keys with --json-output. These would be exactly the same:
-
-  --json-output --json-keys=all -
-  --json --json-stream-data=inline
-
-  And these:
-
-  --json-output -
-  --json --json-stream-data=inline --json-key=qpdf
+* Unify code between QPDFJob::doJSONObjects and QPDF::writeJSON. Make
+  sure that the "qpdf" key is always present when json-output is
+  specified.
 
 * Change the name of the "qpdf-v2" key to "qpdf". Use that in place of
   "objects" and change its content to a two-element array whose first
@@ -114,9 +99,10 @@ JSON v2 fixes
 
   This implies a few things:
 
-  * QPDF::writeJSON will have to take an argument indicating whether
-    additional keys are being written which determines whether it
-    outputs the outer braces or not.
+  * Fix --json-help
+
+  * --json-key=objects is only valid for v1. --json-key=qpdf is only
+    valid for v2.
 
   * This changes the policy about additional extra keys. Have a
     guarantee that qpdf will never add a key whose name is or starts

include/qpdf/QPDF.hh

@@ -134,8 +134,17 @@ class QPDF
     void updateFromJSON(std::shared_ptr<InputSource>);
 
     // Write qpdf json format to the pipeline "p". The only supported
-    // version is 2. The finish() method is called on the pipeline at
-    // the end. The decode_level parameter controls which streams are
+    // version is 2.
+    //
+    // If the value of "complete" is true, a complete JSON object
+    // containing only the "qpdf" key is written to the pipeline, and
+    // finish() is called on the pipeline at the end. If the value of
+    // "complete" is false, the "qpdf" key and its value are written
+    // to the pipeline assuming that a dictionary is already open, and
+    // finish() is not called. The parameter first_key indicates
+    // whether this is the first key if in-progress dictionary.
+    //
+    // The decode_level parameter controls which streams are
     // uncompressed in the JSON. Use qpdf_dl_none to preserve all
     // stream data exactly as it appears in the input. The possible
     // values for json_stream_data can be found in qpdf/Constants.h
@@ -158,6 +167,8 @@ class QPDF
     void writeJSON(
         int version,
         Pipeline* p,
+        bool complete,
+        bool first_key,
         qpdf_stream_decode_level_e decode_level,
         qpdf_json_stream_data_e json_stream_data,
         std::string const& file_prefix,

job.sums

@@ -8,10 +8,10 @@ include/qpdf/auto_job_c_pages.hh b3cc0f21029f6d89efa043dcdbfa183cb59325b6506001c
 include/qpdf/auto_job_c_uo.hh ae21b69a1efa9333050f4833d465f6daff87e5b38e5106e49bbef5d4132e4ed1
 job.yml 3b2b3c6f92b48f6c76109711cbfdd74669fa31a80cd17379548b09f8e76be05d
 libqpdf/qpdf/auto_job_decl.hh 74df4d7fdbdf51ecd0d58ce1e9844bb5525b9adac5a45f7c9a787ecdda2868df
-libqpdf/qpdf/auto_job_help.hh 3aaae4cde004e5314d3ac6d554da575e40209c0f0611f6a308957986f9c7967b
+libqpdf/qpdf/auto_job_help.hh db2e4350c700e064b204e3e20d4fee4eddfe312b28092afcf608b4b6863d30e5
 libqpdf/qpdf/auto_job_init.hh 7ea8e0641dc26fdfba6e283e14dbbff0c016654e174cdace8054f8bef53750fd
 libqpdf/qpdf/auto_job_json_decl.hh 06caa46eaf71db8a50c046f91866baa8087745a9474319fb7c86d92634cc8297
 libqpdf/qpdf/auto_job_json_init.hh 5f6b53e3c81d4b54ce5c4cf9c3f52d0c02f987c53bf8841c0280367bad23e335
 libqpdf/qpdf/auto_job_schema.hh 9d543cd4a43eafffc2c4b8a6fee29e399c271c52cb6f7d417ae5497b3c1127dc
 manual/_ext/qpdf.py 6add6321666031d55ed4aedf7c00e5662bba856dfcd66ccb526563bffefbb580
-manual/cli.rst ad8b234c24569e41c7929f729bb2188f86cd94b8fea5905b71802673cec92eed
+manual/cli.rst 8e1f443c6fa000e023e516c318df4d04d58233d4d8648907c4a71f0ea5722bca

libqpdf/QPDFJob.cc

@@ -3381,6 +3381,8 @@ QPDFJob::writeJSON(QPDF& pdf)
     pdf.writeJSON(
         this->m->json_output,
         fp.get(),
+        true,
+        true,
         this->m->decode_level,
         this->m->json_stream_data,
         file_prefix,

libqpdf/QPDFJob_config.cc

@@ -312,6 +312,9 @@ QPDFJob::Config::jsonOutput(std::string const& parameter)
     if (!o.m->decode_level_set) {
         o.m->decode_level = qpdf_dl_none;
     }
+    if (o.m->json_keys.empty()) {
+        o.m->json_keys.insert("qpdf");
+    }
     return this;
 }
 

libqpdf/QPDF_json.cc

@@ -764,6 +764,8 @@ void
 QPDF::writeJSON(
     int version,
     Pipeline* p,
+    bool complete,
+    bool first_key,
     qpdf_stream_decode_level_e decode_level,
     qpdf_json_stream_data_e json_stream_data,
     std::string const& file_prefix,
@@ -818,7 +820,9 @@ QPDF::writeJSON(
     }
     JSON::writeDictionaryClose(p, first_object, 2);
     JSON::writeDictionaryClose(p, first_qpdf, 1);
-    JSON::writeDictionaryClose(p, first, 0);
-    *p << "\n";
-    p->finish();
+    if (complete) {
+        JSON::writeDictionaryClose(p, first, 0);
+        *p << "\n";
+        p->finish();
+    }
 }

libqpdf/qpdf/auto_job_help.hh

@@ -821,16 +821,18 @@ objects will be shown.
 )");
 ap.addOptionHelp("--json-stream-data", "json", "how to handle streams in json output", R"(--json-stream-data={none|inline|file}
 
-When used with --json-output, this option controls whether
-streams in json output should be omitted, written inline
-(base64-encoded) or written to a file. If "file" is chosen, the
-file will be the name of the output file appended with -nnn where
-nnn is the object number. The prefix can be overridden with
---json-stream-prefix.
+When used with --json, this option controls whether streams in
+json output should be omitted, written inline (base64-encoded)
+or written to a file. If "file" is chosen, the file will be the
+name of the output file appended with -nnn where nnn is the
+object number. The prefix can be overridden with
+--json-stream-prefix. The default is "none", except
+when --json-output is specified, in which case the default is
+"inline".
 )");
 ap.addOptionHelp("--json-stream-prefix", "json", "prefix for json stream data files", R"(--json-stream-prefix=file-prefix
 
-When used with --json-output, --json-stream-data=file-prefix
+When used with --json-stream-data=file, --json-stream-data=file-prefix
 sets the prefix for stream data files, overriding the default,
 which is to use the output file name. Whatever is given here
 will be appended with -nnn to create the name of the file that

manual/cli.rst

@@ -3220,7 +3220,9 @@ Related Options
    This option is repeatable. If given, only the specified top-level
    keys will be included in the JSON output. Otherwise, all keys will
    be included. ``version`` and ``parameters`` will always appear in
-   the output.
+   the output. If not given, all keys will be included, unless
+   :qpdf:ref:`--json-output` was specified, in which case, only the
+   ``"qpdf"`` key will be included by default.
 
 .. qpdf:option:: --json-object={trailer|obj[,gen]}
 
@@ -3241,39 +3243,41 @@ Related Options
 
    .. help: how to handle streams in json output
 
-      When used with --json-output, this option controls whether
-      streams in json output should be omitted, written inline
-      (base64-encoded) or written to a file. If "file" is chosen, the
-      file will be the name of the output file appended with -nnn where
-      nnn is the object number. The prefix can be overridden with
-      --json-stream-prefix.
+      When used with --json, this option controls whether streams in
+      json output should be omitted, written inline (base64-encoded)
+      or written to a file. If "file" is chosen, the file will be the
+      name of the output file appended with -nnn where nnn is the
+      object number. The prefix can be overridden with
+      --json-stream-prefix. The default is "none", except
+      when --json-output is specified, in which case the default is
+      "inline".
 
-   When used with :qpdf:ref:`--json-output`, this option controls
+   When used with :qpdf:ref:`--json`, this option controls
    whether streams in JSON output should be omitted, written inline
    (base64-encoded) or written to a file. If ``file`` is chosen, the
    file will be the name of the output file appended with
    :samp:`-{nnn}` where :samp:`{nnn}` is the object number. The stream
    data file prefix can be overridden with
-   :qpdf:ref:`--json-stream-prefix`. This option only applies when
-   used with :qpdf:ref:`--json-output`.
+   :qpdf:ref:`--json-stream-prefix`. The default value is ``none``,
+   except when :qpdf:ref:`--json-output` is specified, in which case
+   the default is ``inline``.
 
 .. qpdf:option:: --json-stream-prefix=file-prefix
 
    .. help: prefix for json stream data files
 
-      When used with --json-output, --json-stream-data=file-prefix
+      When used with --json-stream-data=file, --json-stream-data=file-prefix
       sets the prefix for stream data files, overriding the default,
       which is to use the output file name. Whatever is given here
       will be appended with -nnn to create the name of the file that
       will contain the data for the stream stream in object nnn.
 
-   When used with :qpdf:ref:`--json-output`,
+   When used with ``--json-stream-data=file``,
    ``--json-stream-data=file-prefix`` sets the prefix for stream data
    files, overriding the default, which is to use the output file
    name. Whatever is given here will be appended with :samp:`-{nnn}`
    to create the name of the file that will contain the data for the
-   stream stream in object :samp:`{nnn}`. This option only applies
-   when used with :qpdf:ref:`--json-output`.
+   stream stream in object :samp:`{nnn}`.
 
 .. qpdf:option:: --json-output[=version]
 
@@ -3288,12 +3292,22 @@ Related Options
    in qpdf JSON format at the given version. ``version`` may be a
    specific version or ``latest`` (the default). The only supported
    version is 2. See also :qpdf:ref:`--json-stream-data` and
-   :qpdf:ref:`--json-stream-prefix`. When this option is specified,
-   the default decode level for stream data is ``none``, but you can
-   override it with :qpdf:ref:`--decode-level`. If you want to look at
-   the contents of streams easily as you would in QDF mode (see
-   :ref:`qdf`), you can use ``--decode-level=generalized`` and
-   ``--json-stream-data=file`` for a convenient way to do that.
+   :qpdf:ref:`--json-stream-prefix`. This option also changes the
+   following defaults:
+
+   - The default value for :qpdf:ref:`--json-stream-data` changes from
+     ``none`` to ``inline``.
+
+   - The default decode level for stream data becomes ``none``, but you can
+     override it with :qpdf:ref:`--decode-level`.
+
+   - Only the ``"qpdf"`` key is included in the JSON output, but you
+     can add additional keys with :qpdf:ref:`--json-key`.
+
+   If you want to look at the contents of streams easily as you would
+   in QDF mode (see :ref:`qdf`), you can use
+   ``--decode-level=generalized`` and ``--json-stream-data=file`` for
+   a convenient way to do that.
 
 .. qpdf:option:: --json-input