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The module is dependent on the Helpful Libraries module, so make sure to install it first!
Combinator needs at least Orchard 1.8!

The module is also available for DotNest sites.

The module's admin settings

After installation the module adds a settings page to the Settings menu. You can also empty the cache there.
Note: Currently the module preserves a combined resource forever, without updating it if the resources have changed. If you have modified a stylesheet or javascript file (or its resource's settings, like conditions) and want to see the updates you should empty the cache. If the list of resource for a specific page changes, however (e.g. from Script1.js, Script2.js to include Script3.js too), Combinator will produce a new resource.
Note that Combinator also has a command line argument for emptying the cache: "combinator empty".

Exclusion filters and why they matter

You can set exclusion filters (regular expressions) on combination, minification and image embedding.
  • Sometimes a resource does not play well with combination: e.g. WYSIWYG editors (like TinyMCE) tend to load scripts on the fly, based on relative paths to the script's location. Combinator can do nothing with such mechanisms, so it's better not to touch them: therefore, excluding from combination is the way to go.
  • Javascript minification is not bullet-proof, there are rare cases (mostly with already minified scripts) when the produced script is syntactically incorrect. To overcome this, you can exclude such scripts from minification.
  • Excluding stylesheets from embedding their images is useful for conditional stylesheets specifically targeted at browsers that don't support data urls.

Development best practices

  • Don't have Combinator always enabled in your development (and testing) environment, as combined resources make it harder to find bugs in resources. Only enable Combinator steadily in the live environment.
  • You should, however, always test the impact of the module on your site. Try all pages where distinct sets of resources are used.
  • When testing in the development environment, don't have Shape Tracing enabled.
  • Always empty the cache in the live environment when you push resource changes to it.
  • Unless you adjust the urls to be the same, you can't push combined resources to the live environment (since Combinator adjusts relative paths, these will include the url of your development environment; however if you don't have AppPath set you should be able to publish to live, but if you have one, like the default "OrchardLocal", resources should be recompiled in live). Therefore, it's best to publish changes with the cache emptied and let combination happen on the live site (which will only cause a performance impact on the first views of pages with unique set of resources).
  • If you're using resource sharing check whether tenants can have different resources with the same paths because that would cause inconsistencies. E.g. if you have a module that provides a dynamic (e.g. user-configurable) stylesheet under the fixed path /dynamicstylesheet, where the path does not contain anything unique to the tenant (what would be e.g. /tenantname/dynamicstylesheet) then this stylesheet will be shared among all the tenants. Resource sharing only works if the resources with the same path also contain the same data.
  • Until this issue is fixed, place font-face CSS declarations into separate CSS files and exclude them from combination.

Important notes on sprite generation

Image sprite generation features a partially automatic detection whether an image is suitable for sprite generation or not: backgrounds with a size, position other than top-left, and repetition other than no-repeat are excluded. Only images with the these criteria are used for sprite generation.

However, Combinator can do nothing when these properties are set somewhere else than in the block of the background declaration. Therefore if an image
  • has those properties set somewhere,
  • is already a sprite or
  • its container's size exceeds its size
then exclude it manually by using "no-sprite" in their file path or by adding the ".no-sprite" class to the selectors of the css block they're included in.

Warning: sprite generation is experimental not only itself but it also needs the ExCSS library to work. The latter one is undergoing heave refactoring but the current release can fail on some CSS files and produce incorrect results, thus rendering the CSS produced by Combinator incorrect too.

Notes on using with Azure Blob storage

If your site runs on Azure Cloud Services or Azure Web Sites (probably this also affects Azure VMs) and uses Blob storage to store media files then you have to take the below actions to ensure that resources processed by Combinator are properly served.

When Orchard stores files in Blob storage it also sets their mime types; this is then also used when serving the files. For JavaScript files the mime type should be "application/javascript". However on Azure webservers are missing the correct mime map for JavaScript files, thus also the mime type of processed scripts is set wrong (or not set at all). Orchard, by default, reads mime types first from the Web.config, then from the registry. So to fix this the easiest way is to set up the correct mime map in your site's Web.config as following:

      <remove fileExtension=".js" />
      <mimeMap fileExtension=".js" mimeType="application/javascript" />


If something fails, Combinator returns the original set of resources for a specific resource type (like head scripts) or even for all resources, depending on the type of failure. So if looking at the html source you see that nothing has changed then something has gone wrong. Possible causes are that a local or remote resource was not found or an exclusion regex was erroneous. Take a look at the log file to see what happened. If you're in doubt what have caused the failure, don't be afraid to ask.

Who's using it?

Among others Combinator speeds up the Orchard Gallery, all sites on DotNest, the Hungarian Orchard Community site, all the Lombiq sites like and Orchard Dojo, and the Associativy home page. If you use and like Combinator, let me know and your site will be listed here.

Many thanks

To randompete, Sebastien Ros (for the incredible overridden stylesheet discovery) and Znowman for their valuable contributions!

See the Version history

Last edited Nov 23, 2015 at 11:11 PM by MilanKeszthelyi, version 54


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