The 'ifexists' atom allows us to print a required format if the
preceeding atom has a value. If the preceeding atom has no value then
the format given is not printed. e.g. to print "[<refname>]" we can
now use the format "%(ifexists:[%s])%(refname)".

Add documentation and test for the same.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Matthieu Moy <matthieu....@grenoble-inp.fr>
Signed-off-by: Karthik Nayak <karthik....@gmail.com>
---
 Documentation/git-for-each-ref.txt |  8 ++++++++
 ref-filter.c                       | 37 ++++++++++++++++++++++++++++++++++---
 ref-filter.h                       |  5 +++--
 t/t6302-for-each-ref-filter.sh     | 21 +++++++++++++++++++++
 4 files changed, 66 insertions(+), 5 deletions(-)

diff --git a/Documentation/git-for-each-ref.txt 
b/Documentation/git-for-each-ref.txt
index 9dc02aa..4424020 100644
--- a/Documentation/git-for-each-ref.txt
+++ b/Documentation/git-for-each-ref.txt
@@ -138,6 +138,14 @@ colornext::
        `<:colorname>`.  Not compatible with `padright` and resets any
        previous `color`, if set.
 
+ifexists::
+       Print required string only if the next atom specified in the
+       '--format' option exists.
+       e.g. --format="%(ifexists:[%s])%(symref)" prints the symref
+       like "[<symref>]" only if the ref has a symref.  This was
+       incorporated to simulate the output of 'git branch -vv', where
+       we need to display the upstream branch in square brackets.
+
 In addition to the above, for commit and tag objects, the header
 field names (`tree`, `parent`, `object`, `type`, and `tag`) can
 be used to specify the value in the header field.
diff --git a/ref-filter.c b/ref-filter.c
index 3f40144..ff5a16b 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -58,6 +58,7 @@ static struct {
        { "color" },
        { "padright" },
        { "colornext" },
+       { "ifexists" },
 };
 
 /*
@@ -722,6 +723,13 @@ static void populate_value(struct ref_array_item *ref)
                        v->modifier_atom = 1;
                        v->color_next = 1;
                        continue;
+               } else if (starts_with(name, "ifexists:")) {
+                       skip_prefix(name, "ifexists:", &v->s);
+                       if (!*v->s)
+                               die(_("no string given with 'ifexists:'"));
+                       v->modifier_atom = 1;
+                       v->ifexists = 1;
+                       continue;
                } else
                        continue;
 
@@ -1315,11 +1323,32 @@ static void apply_formatting_state(struct 
ref_formatting_state *state,
 {
        if (state->color_next && state->pad_to_right)
                die(_("cannot use `colornext` and `padright` together"));
-       if (state->color_next) {
+       if (state->pad_to_right && state->ifexists)
+               die(_("cannot use 'align' and 'ifexists' together"));
+       if (state->color_next && !state->ifexists) {
                strbuf_addf(value, "%s%s%s", state->color_next, v->s, 
GIT_COLOR_RESET);
                return;
-       }
-       else if (state->pad_to_right) {
+       } else if (state->ifexists) {
+               const char *sp = state->ifexists;
+
+               while (*sp) {
+                       if (*sp != '%') {
+                               strbuf_addch(value, *sp++);
+                               continue;
+                       } else if (sp[1] == '%') {
+                               strbuf_addch(value, *sp++);
+                               continue;
+                       } else if (sp[1] == 's') {
+                               if (state->color_next)
+                                       strbuf_addf(value, "%s%s%s", 
state->color_next, v->s, GIT_COLOR_RESET);
+                               else
+                                       strbuf_addstr(value, v->s);
+                               sp += 2;
+                       }
+               }
+
+               return;
+       } else if (state->pad_to_right) {
                if (!is_utf8(v->s))
                        strbuf_addf(value, "%-*s", state->pad_to_right, v->s);
                else {
@@ -1413,6 +1442,8 @@ static void store_formatting_state(struct 
ref_formatting_state *state,
                state->color_next = atomv->s;
        if (atomv->pad_to_right)
                state->pad_to_right = atomv->ul;
+       if (atomv->ifexists)
+               state->ifexists = atomv->s;
 }
 
 static void reset_formatting_state(struct ref_formatting_state *state)
diff --git a/ref-filter.h b/ref-filter.h
index a021b04..7d1871d 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -28,13 +28,14 @@ struct atom_value {
        unsigned long ul; /* used for sorting when not FIELD_STR */
        unsigned int modifier_atom : 1, /*  atoms which act as modifiers for 
the next atom */
                pad_to_right : 1,
-               color_next : 1;
+               color_next : 1,
+               ifexists : 1;
 };
 
 struct ref_formatting_state {
        int quote_style;
        unsigned int pad_to_right;
-       const char *color_next;
+       const char *color_next, *ifexists;
 };
 
 struct ref_sorting {
diff --git a/t/t6302-for-each-ref-filter.sh b/t/t6302-for-each-ref-filter.sh
index 6aad069..29ed97b 100755
--- a/t/t6302-for-each-ref-filter.sh
+++ b/t/t6302-for-each-ref-filter.sh
@@ -149,4 +149,25 @@ test_expect_success 'check `colornext` format option' '
        test_cmp expect actual
 '
 
+test_expect_success 'check `ifexists` format option' '
+       cat >expect <<-\EOF &&
+       [foo1.10]
+       [foo1.3]
+       [foo1.6]
+       EOF
+       git for-each-ref --format="%(ifexists:[%s])%(refname:short)" | grep 
"foo" >actual &&
+       test_cmp expect actual
+'
+
+cat >expect <<EOF &&
+[$(get_color green)foo1.10$(get_color reset)]||foo1.10
+[$(get_color green)foo1.3$(get_color reset)]||foo1.3
+[$(get_color green)foo1.6$(get_color reset)]||foo1.6
+EOF
+
+test_expect_success 'check `ifexists` with `colornext` format option' '
+       git for-each-ref 
--format="%(ifexists:[%s])%(colornext:green)%(refname:short)||%(refname:short)" 
| grep "foo" >actual &&
+       test_cmp expect actual
+'
+
 test_done
-- 
2.4.6

--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to