[fix] make /stats more CSP compliant - bar graph

Replace bar graph's *styles* (see below) by CSP compliant implementation in
``searx/static/themes/__common__/less/stats.less`` ::

    ./simple/stats.html:49: <span style="width: calc(max(2px, 100%*{{ (engine_stat.result_count / engine_stats.max_result_count )|round(3) }}))" class="stacked-bar-chart-serie1"></span>{{- "" -}}
    ./simple/stats.html:57: <span style="width: calc(max(2px, 100%*{{ (engine_stat.http / engine_stats.max_time )|round(3) }}))" class="stacked-bar-chart-serie1"></span>{{- "" -}}
    ./simple/stats.html:58: <span style="width: calc(100%*{{ engine_stat.processing / engine_stats.max_time |round(3) }})" class="stacked-bar-chart-serie2"></span>{{- "" -}}
    ./oscar/stats.html:50:  <span style="width: calc(max(2px, 100%*{{ (engine_stat.result_count / engine_stats.max_result_count )|round(3) }}))" class="stacked-bar-chart-serie1"></span>{{- "" -}}
    ./oscar/stats.html:58:  <span style="width: calc(max(2px, 100%*{{ (engine_stat.http / engine_stats.max_time )|round(3) }}))" class="stacked-bar-chart-serie1"></span>{{- "" -}}
    ./oscar/stats.html:59:  <span style="width: calc(100%*{{ engine_stat.processing / engine_stats.max_time |round(3) }})" class="stacked-bar-chart-serie2"></span>{{- "" -}}

Reported-by: https://github.com/searxng/searxng/issues/57
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

1 files changed, 38 insertions, 0 deletions

diff --git a/searx/static/themes/__common__/less/stats.less b/searx/static/themes/__common__/less/stats.less
new file mode 100644
index 000000000..6c2117b39
--- /dev/null
+++ b/searx/static/themes/__common__/less/stats.less
@@ -0,0 +1,38 @@
+.bar-chart-value {
+    width: 3em;
+}
+
+.bar-chart-graph {
+    width: 300px;
+}
+
+.bar-chart-bar {
+    border: 3px solid #5bc0de;
+    margin: 1px 0;
+}
+
+.bar-chart-serie1 {
+    border: 3px solid #5bc0de;
+    margin: 1px 0;
+    float: left;
+}
+
+.bar-chart-serie2 {
+    border: 3px solid #deb15b;
+    margin: 1px 0;
+    float: left;
+}
+
+.bar0{
+    width: 0;
+    border: 0;
+}
+
+.generate-bar(100);
+
+.generate-bar(@n, @i: 1) when (@i =< @n) {
+  .bar@{i} {
+    width: (@i * 100% / @n);
+  }
+  .generate-bar(@n, (@i + 1));
+}