Adding USGSCSM plugin to ISIS (#37)

# Adding USGSCSM Plugin to ISIS

???+ warning

      Upcoming ISIS version 8.2 and future releases will include the USGSCSM library and does __not__ require a separate installation of the plugin.

      ISIS versions 8.0LTS, 8.1, and earlier _require_ a separate installation of the USGSCSM plugin as shown below.

## For users

You can install the latest [USGSCSM](https://github.com/DOI-USGS/usgscsm) library via conda:

```sh

conda install conda-forge::usgscsm

```

## For developers

???+ info

    For USGSCSM versions 2.0 and above, the plugin is installed in `$CONDA_PREFIX/lib/csmplugins/` in an Anaconda environment.

### Plugin setup

If you are testing a new plugin or using older versions of USGSCSM/ISIS, you will need to update your `IsisPreferences` file located under the `ISIS3/isis` directory with the appropriate plugin path change. 

For example, if your `CONDA_PREFIX` path is not the same are your `ISISROOT` path, you can add `"$CONDA_PREFIX/lib/csmplugins/"` to your `IsisPreferences` file under `Group = Plugins`:

  ```

  Group = Plugins

    CSMDirectory = ("$CONDA_PREFIX/lib/csmplugins/", -

                    "$ISISROOT/lib/csmplugins/", -

                    "$ISISROOT/lib/isis/csm3.0.3/", -

                    "$ISISROOT/csmlibs/3.0.3/", -

                    "$HOME/.Isis/csm3.0.3/")

  EndGroup

  ```

### Using your local build

If you are working on USGSCSM, you can build a local conda package of USGSCSM and install that in your ISIS conda environment for testing. 

#### Step 1: Create your local build

First, activate your ISIS environment:

```sh

conda activate isis3

```

Second, go to your USGSCSM `/build` directory if it already exists and remove the CMakeCache.txt file:

```sh

cd <path-to-repos>/usgscsm/build

rm -rf CMakeCache.txt

```

Third, run `cmake` while specifying the installation to be located in your currently activated conda environment's directory:

```sh

cmake .. -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX/

```

???+ note

    Verify that you are in an activated conda environment: `echo $CONDA_PREFIX`

Once the `cmake` command has finished running, build and install your local build:

```sh

make

make install

```

#### Step 2: Install your local build

First, make sure you are in the conda environment you installed the USGSCSM library to.

Second, check if the USGSCSM package is conda installed. If so, remove it from your environment:

```sh

conda list usgscsm

conda remove --force usgscsm

```

Third, remove the cmake cache from your ISIS build dir and [re-build ISIS](../isis-developer-guides/developing-isis3-with-cmake.md#building-isis3):

```sh

cd <path-to-repos>/ISIS3/build

rm -rf CMakeCache.txt

```

#### Step 3: Test your local build

Make sure your local build of USGSCSM is installed properly by running `csminit`:

```sh

which csminit

csminit -h

```

      - Installing ISIS Via Anaconda:      how-to-guides/environment-setup-and-maintenance/installing-isis-via-anaconda.md

      - Anaconda in a Network Environment: how-to-guides/environment-setup-and-maintenance/anaconda-in-a-network-environment.md

      - SPICE Kernel Updates in ISIS:      how-to-guides/environment-setup-and-maintenance/spice-kernel-updates-in-isis.md

      - Adding USGSCSM Plugin to ISIS:     how-to-guides/environment-setup-and-maintenance/adding-usgscsm-plugin-to-isis.md

    - SPICE: 

      - Creating Spice Config Files in SpiceQL: how-to-guides/SPICE/creating-spice-config-files-in-spiceql.md

    - Image Processing: