", line 17, in main
AttributeError: qSlicerExtensionsManagerModel has no attribute named 'retrieveExtensionMetadataByName'
```
the command hangs, and the installation does not take place.
So maybe something changed from the version you used at the time (5.0.2 according to the commit message) and 5.2.2?
---
### Author:  [@jcfr](https://discourse.slicer.org/u/jcfr)
#### Post date: [August 30, 2023, 4:53am UTC](https://discourse.slicer.org/t/install-extensions-from-the-command-line-using-slicer-5-2-2/31439/5 "2023-08-30T04:53:11Z")
Starting with Slicer 5.4, a dedicated API was introduced to streamline the programmatic installation of extensions.
See [https://slicer.readthedocs.io/en/latest/developer\_guide/script\_repository.html#download-and-install-extension](https://slicer.readthedocs.io/en/latest/developer_guide/script_repository.html#download-and-install-extension)
---
### Author:  [@jhlegarreta](https://discourse.slicer.org/u/jhlegarreta)
#### Post date: [August 30, 2023, 12:48pm UTC](https://discourse.slicer.org/t/install-extensions-from-the-command-line-using-slicer-5-2-2/31439/6 "2023-08-30T12:48:17Z")
Steve already pointed to that possibility for Slicer 5.4; I’m using 5.2.2, though.
---
### Author:  [@jcfr](https://discourse.slicer.org/u/jcfr)
#### Post date: [August 30, 2023, 1:15pm UTC](https://discourse.slicer.org/t/install-extensions-from-the-command-line-using-slicer-5-2-2/31439/7 "2023-08-30T13:15:09Z")
> [@jhlegarreta](#):
>
> So maybe something changed from the version you used at the time (5.0.2 according to the commit message) and 5.2.2?
See [BUG: fix/doc DMRIInstall (#6594) · Slicer/Slicer@537281b · GitHub](https://github.com/Slicer/Slicer/commit/537281b6cfeaa3bdf9f35538efb53846a2fe3729#diff-1c3362f027f4595ea24d34d4627256f9d63d418fcddbd325fe8d022829c611ac)
---
### Author:  [@jhlegarreta](https://discourse.slicer.org/u/jhlegarreta)
#### Post date: [August 30, 2023, 1:24pm UTC](https://discourse.slicer.org/t/install-extensions-from-the-command-line-using-slicer-5-2-2/31439/8 "2023-08-30T13:24:22Z")
Hitting the very same error reported earlier even when modifying the script according to it.
---
### Author:  [@jcfr](https://discourse.slicer.org/u/jcfr)
#### Post date: [August 30, 2023, 1:33pm UTC](https://discourse.slicer.org/t/install-extensions-from-the-command-line-using-slicer-5-2-2/31439/9 "2023-08-30T13:33:02Z")
With Slicer \>= 5.2, consider using the following script:
```python
import os
extensionName = os.environ['EXTENSION_TO_INSTALL']
em = slicer.app.extensionsManagerModel()
if not em.isExtensionInstalled(extensionName):
em.interactive = False # prevent display of popups
em.updateExtensionsMetadataFromServer(True, True) # update extension metadata from server now
installDependencies = True
if not em.downloadAndInstallExtensionByName(extensionName, installDependencies, True):
raise ValueError(f"Failed to install {extensionName} extension")
```
Assuming you saved it as `/tmp/install_slicer_extension.py`, you may run it using:
```bash
$ EXTENSION_TO_INSTALL=Sandbox \
~/Downloads/Slicer-5.2.2-linux-amd64/Slicer \
--exit-after-startup \
--no-main-window \
--disable-modules \
--python-script /tmp/install_slicer_extension.py
Retrieving extension metadata for Sandbox extension
Retrieving Sandbox extension files (extensionId: 63f5ca688939577d9867ba35)
Downloading Sandbox extension (item_id: 63f5ca688939577d9867ba35, file_id: 64c8c82516826926710d5a97)
Installed extension Sandbox (63f5ca688939577d9867ba35) revision e163d61
```
---
### Author:  [@jcfr](https://discourse.slicer.org/u/jcfr)
#### Post date: [August 30, 2023, 1:42pm UTC](https://discourse.slicer.org/t/install-extensions-from-the-command-line-using-slicer-5-2-2/31439/10 "2023-08-30T13:42:34Z")
And here is an improved version allowing to install extensions in Slicer 5.2.2 while passing extension names as regular arguments:
```python
import sys
def install_exttension(extensionName, installDependencies=True):
print(f"\nInstalling extension {extensionName}")
em = slicer.app.extensionsManagerModel()
if em.isExtensionInstalled(extensionName):
print(f"Extension {extensionName} already installed")
return
em.interactive = False # prevent display of popups
em.updateExtensionsMetadataFromServer(True, True) # update extension metadata from server now
if not em.downloadAndInstallExtensionByName(extensionName, installDependencies, True):
raise ValueError(f"Failed to install {extensionName} extension")
if __name__ == " __main__":
for extensionName in sys.argv[1:]:
install_exttension(extensionName)
```
For future reference, to install extension in Slicer 5.4, there is a dedicated API to do so. See [here](https://slicer.readthedocs.io/en/5.4/developer_guide/script_repository.html#download-and-install-extension)
Then, to install extensions:
```bash
$ ads/Slicer-5.2.2-linux-amd64/Slicer \
--exit-after-startup \
--no-main-window \
--disable-modules \
--python-script /tmp/install_slicer_extension.py \
Sandbox \
SlicerHeart \
SlicerDMRI
```
and example of output:
```plaintext
Installing extension Sandbox
Retrieving extension metadata for Sandbox extension
Retrieving Sandbox extension files (extensionId: 63f5ca688939577d9867ba35)
Downloading Sandbox extension (item_id: 63f5ca688939577d9867ba35, file_id: 64c8c82516826926710d5a97)
Installed extension Sandbox (63f5ca688939577d9867ba35) revision e163d61
Installing extension SlicerHeart
Retrieving extension metadata for SlicerHeart extension
Retrieving SlicerHeart extension files (extensionId: 63f5f3f08939577d9867dbc7)
Downloading SlicerHeart extension (item_id: 63f5f3f08939577d9867dbc7, file_id: 64de321206a93d6cff35a4c1)
"The following extensions are required by SlicerHeart extension therefore they will be installed now: SlicerIGT, SlicerIGSIO"
Retrieving extension metadata for SlicerIGT extension
Retrieving SlicerIGT extension files (extensionId: 63f5f2d78939577d9867da34)
Downloading SlicerIGT extension (item_id: 63f5f2d78939577d9867da34, file_id: 64aa9a94b81c954f339bfef6)
Retrieving extension metadata for SlicerIGSIO extension
Retrieving SlicerIGSIO extension files (extensionId: 63f5da488939577d9867c528)
Downloading SlicerIGSIO extension (item_id: 63f5da488939577d9867c528, file_id: 64c0f2c6c0e19dd3b30f7352)
Installed extension SlicerHeart (63f5f3f08939577d9867dbc7) revision 09e440d
Installed extension SlicerIGT (63f5f2d78939577d9867da34) revision 245fa92
Installed extension SlicerIGSIO (63f5da488939577d9867c528) revision b6328fd
Installing extension SlicerDMRI
Retrieving extension metadata for SlicerDMRI extension
Retrieving SlicerDMRI extension files (extensionId: 63fb32ce8939577d9869e2b2)
Downloading SlicerDMRI extension (item_id: 63fb32ce8939577d9869e2b2, file_id: 64ccc3ed16826926710f2500)
"The following extensions are required by SlicerDMRI extension therefore they will be installed now: UKFTractography"
Retrieving extension metadata for UKFTractography extension
Retrieving UKFTractography extension files (extensionId: 63f5eae38939577d9867d2b3)
Downloading UKFTractography extension (item_id: 63f5eae38939577d9867d2b3, file_id: 63f5eae38939577d9867d2ba)
Installed extension SlicerDMRI (63fb32ce8939577d9869e2b2) revision aad4331
Installed extension UKFTractography (63f5eae38939577d9867d2b3) revision fcf83e2
```
---
### Author:  [@jhlegarreta](https://discourse.slicer.org/u/jhlegarreta)
#### Post date: [August 30, 2023, 2:59pm UTC](https://discourse.slicer.org/t/install-extensions-from-the-command-line-using-slicer-5-2-2/31439/11 "2023-08-30T14:59:10Z")
OK, after some more work, got it working: looks like I had still carried over the statement to call `retrieveExtensionMetadataByName` in [https://github.com/pieper/SlicerDockers/blob/master/slicer-plus/install-slicer-extension.py#L7C3-L7C77](https://github.com/pieper/SlicerDockers/blob/master/slicer-plus/install-slicer-extension.py#L7C3-L7C77), so the instructions in [Install extensions from the command line using Slicer 5.2.2 - #10 by jcfr](https://discourse.slicer.org/t/install-extensions-from-the-command-line-using-slicer-5-2-2/31439/10) worked.
Thanks for the effort @jcfr.