How To Create a Customised Theme For SLM Availability Reports¶
The HTML version of customer’s Availability Reports can be modified on a per-customer basis, allowing therefore to provide reports with a unique, tailored layout to each customer.
This feature works currently only from the command line; hence a basic degree of knowledge and acquaintance with the Linux command line and with HTML and CSS is required in order to successfully complete this howto.
Custom reports are built using the Handlebars templating engine; hence all necessary file that you would use need to have the .hbs extension (like e.g., custom_logo.hbs). You can find some basic notions of Handlebar’s syntax and capabilities in the official language guide.
First of all, we mention some important directory that will be used next:
Default templates can be found and reused from
/usr/share/slmd/templates/
Customised templates are stored in a directory under
/neteye/shared/slmd/conf/custom_templates/
Scenario¶
We want to customise a theme for SLM Availability Report for customer ACME, Inc., which conforms to their corporate identity, by adding (1) their logo and (2) the font they use in all its reports, that is, for the daily, weekly, and monthly reports.
Step #1: Copy the necessary files¶
The first step is to create a new directory in which to store the customised files. We’ll call it simply acme:
.. code:: bash
# mkdir -p /neteye/shared/slmd/conf/custom_templates/acme/partials # ls -l /neteye/shared/slmd/conf/custom_templates/acme/
total 0
drwxr-xr-x. 2 root root 6 Jun 17 15:16 partials
Next, we need to copy there all the necessary files; we mentioned that
default templates are in /usr/share/slmd/templates
. Under that
directory, you find the following files:
├── partials
│ ├── report_legend.hbs
│ ├── report_header.hbs
│ ├── report_footer.hbs
│ └── outages_report.hbs
├── weekly_report_template.hbs
├── monthly_report_template.hbs
└── daily_report_template.hbs
Files right under the templates
directory define the structure of
the build daily, weekly, and monthly reports and pull the content from
SLM data, while files under the templates/partials
directory contain
only part of the reports and might be included or not in the
above-mentioned three reports.
Since we want to customise the logo in the header, we copy only
partials/report_header.hbs
:
.. code:: bash
# cp /usr/share/slmd/templates/partials/report_header.hbs /neteye/shared/slmd/conf/custom_templates/acme/partials
In order to customise a whole report, you should copy also the
appropriate daily, weekly, or monthly template under the acme
directory you just created, for example, to modify only the daily
template, copy the daily_report_template.hbs:
.. code:: bash
# cp /usr/share/slmd/templates/daily_report_template.hbs /neteye/shared/slmd/conf/custom_templates/acme/
If you do not copy any of the daily, weekly, or monthly report, the report_header.hbs file will be used for all templates, which is indeed what is required in our sample scenario.
Note
The acme template will now be shown in the drop-down menu called Report Template that appears when you add a new customer under
.Step #2: Add the logo¶
The logo needs to be encoded in base64; under Linux you can simply use the application with the application of the same name (there exist online converters as well):
.. code:: bash
# base64 logo.png > /neteye/shared/slmd/conf/custom_templates/acme/partials/acme_logo.hbs
We pipe the output to a file, so it is immediately available for inclusion in the templates.
By using the {{~> partials/acme_logo ~}}
syntax, indeed, Handlebars
will look for a file called acme_logo and replace that whole string
with the verbatim content of the file, in this case the
acme_logo.hbs file saved in the partials
directory.
You can then edit the file report_header.hbs and add the string
{{~> partials/acme_logo ~}}
in the most appropriate place of the
template, making sure to omit the suffix:
<!-- Partial - SLM Report Header -->
<!-- SLM Report Name -->
<section class="section section--evencolumns">
<img src="data:image/png;base64,{{~> partials/logo~}}" />
<div class="wpcol wpcol--2of3">
<h1 class="title title--large">{{report_data.report_name}}</h1>
</div>
</section>
Note that the path is always relative to the base directory, which
in this case is /neteye/shared/slmd/conf/custom_templates/acme
.
Step #3: Customise the CSS¶
Since ACME corporate identity uses a given font, Lato
, we want its
template to mimic it; therefore we need to change the reports’ style to
use that font by default.
Remaining under the partials
directory, we create a new file
acmestyle.hbs with the following content:
<style>
body {
font-family:"Lato","Helvetica New",Arial,sans-serif;
}
</style>
As you can see from this snippet, only inline CSS is supported in templates. As the last task, we need to tell the header to use the the custom CSS. Similar to what we did in the previous step for the logo, we need to make sure that the template includes this file:
<!-- Partial - SLM Report Header -->
{{~> partials/acmestyle ~}}
<!-- SLM Report Name -->
<section class="section section--evencolumns">
{{~> partials/custom_logo ~}}
<div class="wpcol wpcol--2of3">
<h1 class="title title--large">{{report_data.report_name}}</h1>
</div>
</section>
You can now use your fully customised template for ACME, Inc.’s report templates: edit the ACME, Inc. customer under SLM > Customers and assign to it the acme template.
Conclusions¶
We have shown how to modify a few characteristics of a report template,
but many more possibilities exists: you can completely revamp the layout
of the templates by adding a completely customised CSS; you can add a
background image to the report, modify the fonts used for every
component of the HTML report (div
, span
, h2
etc).
When dealing with Handlebars, like for any other templating engine, it is nonetheless important to focus on two points:
There is no check on the syntax of the file(s) you include, so make sure that the elements you include are valid (like, e.g., CSS and HTML structure and syntax, correctly encoded images, and so on)
In the template, all the strings that need to pull data and content from the SLM backend must be enclosed in double curly braces (like, e.g.,
{{month_day_number}}
or{{translate "report.common.week_days.short.mon"}}