Extend Site Designs With Microsoft Flow In SharePoint Online

Overview

The Modern site offers two out of the box templates - Team Site and Collaboration Site. These templates can be extended by using Site Designs to provision additional SharePoint artifacts on the site.

The Site design can be based on either Team site or Collaboration site. Site design can be associated with one or multiple site scripts. Each site script can have series of actions that gets executed.

SharePoint Online Site Creation Process

Open SharePoint tile (https://tenant.sharepoint.com/_layouts/15/sharepoint.aspx)
It offers an option to create a new Modern SharePoint site.
The available site designs (out of box and custom) appears in site creation process.
After selection of site design, providing site name and option site description, click Finish.
During the site design application process, the Modern site with base site design gets created. During the site creation process, the selected site design applies the associated site scripts.
After the site scripts have finished running, we will see the updates to the site.

Limitation of Site Scripts

The actions in site script are limited and do not fit all possible scenarios, for example adding footer to every page or creating pages.
The Site script has a limit of 30 cumulative actions that can be specified across one or more site scripts including sub actions. If we want to execute more than 30 actions to suffice our business requirements, we have to raise our voice to Microsoft with business justification.

However, during the time we are not limited. The site script supports calling Microsoft flows. We can extend this functionality to provision additional artifacts to SharePoint site.

{
"$schema": "schema.json",
"actions": [
{
"verb": "triggerFlow",
"url": "[paste the workflow trigger URL here]",
"name": "Apply Template",
"parameters": {
"event":"",
"product":""
}
}
],
"bindata": {},
"version": 1
}

Site Design Extensibility Process

The below diagram explains the process to extend the site design using Microsoft flow.

We will require below components to setup,

Site design and associated site script
Microsoft Flow
Azure Storage Queue
Azure Function
PnP Provisioning template
PowerShell Script
App ID and App secret with administrative rights on Office 365 tenant

Step 1 - Setup App Only Access to Office 365 Tenant

Setup on normal SharePoint site

Open SharePoint root site. You may also perform this on any other SharePoint site other than root site
Navigate to url https://[tenant].sharepoint.com/_layouts/15/appregnew.aspx
Generate new Client Id and Client Secret by clicking Generate button next to it.
Enter title for app. Example: "Extend Site Design"
In the App Domain, specify localhost
In the redirect URI, specify https://localhost
Click Create

Note down the Client ID and Client Secret for future reference.

Trust the App for appropriate access to tenant

Open SharePoint central admin site.
Navigate to https://[tenant]-admin.sharepoint.com/_layouts/appinv.aspx
Paste the Client Id to App Id text box
Click Lookup
Paste below XML in Permission Request XML textbox
1. <AppPermissionRequests AllowAppOnlyPolicy="true" >
2. <AppPermissionRequest Scope="http://sharepoint/content/tenant" Right="FullControl" />
3. </AppPermissionRequests>
Click Create
Click Trust It

Step 2 - Create Azure Storage Queue

Azure storage queue will receive a message from Microsoft Flow. When there will be a new message in the queue, an Azure function will be triggered to execute PowerShell script.

Open Azure Portal https://portal.azure.com
Click Create a resource
Select Storage > Storage account - blob, file, table, queue
Provide the values by filling up the form
Click Create
Open Storage account, navigate to Queues.
Create queue with name sitedesignqueue
Click Access keys under Settings
Note down Storage Account Name and the key1 Key value for future reference.

Step 3 - Setup Microsoft Flow

Open SharePoint site
In the next tab navigate to MS Flow (https://flow.microsoft.com)
Click My flows
Click Create from blank
From search results, select Request - When an HTTP Request is received
Search Request
Select Request - When a HTTP Request is received
Enter below JSON as request body
1. {
2. "type": "object",
3. "properties": {
4. "webUrl": {
5. "type": "string"
6. },
7. "parameters": {
8. "type": "object",
9. "properties": {
10. "event": {
11. "type": "string"
12. },
13. "product": {
14. "type": "string"
15. }
16. }
17. }
18. }
19. }
Click New Step
Select Add an action
Search Azure Queues
Select Azure Queues - Put a message on a queue
Enter any name for connection
Enter storage account name
Enter storage shared key
Click Create
Select the queue name
In the message, select webUrl
Click Save
At the end, the flow will look like below
Note down HTTP POST URL for future reference.

Test the flow

Run below PowerShell

$uri = "[Flow URI]"
$body = "{webUrl:'siteurl'}"
Invoke-RestMethod -Uri $uri -Method Post -ContentType "application/json" -Body $body

See the run history, if flow is successful.

Step 4 - Create PnP provisioning template

Connect to SharePoint Modern site using PnP PowerShell

Connect-PnPOnline -Url "SharePoint site url"

Run the below command to generate the provisioning template from the site

Get-PnPProvisioningTemplate -Out .\CustomTemplate.xml -ExcludeHandlers Navigation, ApplicationLifecycleManagement -IncludeNativePublishingFiles

Make edits to the xml or use attached FlowSiteDesignTemplate.xml

Step 5 - Setup Azure Function

Open Azure Portal https://portal.azure.com
Click Create a resource
Select Compute > Function App
In Storage field, select Use existing and select the storage account created earlier.
Click Create
Open Function app. Select Functions > New function
From language dropdown, select PowerShell
Select QueueTrigger - PowerShell
Name function as ApplyPnPProvisioningTemplate
Enter the queue name created earlier
Click Create

Step 6 - Upload PnP PowerShell module to Azure Function

Download PnP PowerShell Module

On local drive create temporary folder

Run the below PowerShell

Save-Module -Name SharePointPnPPowerShellOnline -Path [pathtoyourfolder]

This will download PnP PowerShell module files to local folder

Upload PnP PowerShell Module to Azure function

In the Function app, click Platform features
Under Development tools, select Advanced tools (Kudu)
On Kudu page, under Debug console select either CMD or PowerShell
Navigate to site\wwwroot\[nameofyourazurefunction]
Click New Folder option
Create folder named modules
Inside modules folder, create another folder called SharePointPnPPowerShellOnline
Open SharePointPnPPowerShellOnline folder and drag drop the downloaded PnP PowerShell Module files.

Implement Azure Function

Open Azure function
Click View files
Click Upload
Upload FlowSiteDesignTemplate.xml
Update PowerShell as below
1. $in = Get-Content $triggerInput -Raw
2. Write-Output "PowerShell script processed queue message '$in'"
4. Connect-PnPOnline -AppId $env:SPO_AppId -AppSecret $env:SPO_AppSecret -Url $in
5. Write-Output "Connected to site"
6. Apply-PnPProvisioningTemplate -Path D:\home\site\wwwroot\ApplyPnPProvisioningTemplate\FlowDemoTemplate.xml
7. Write-Output "Finished provisioning to site"
To set the environment variables, select Application Settings
Click Add new setting
Add the below settings

SPO_AppId Value of Client ID created in Step 1: Setup App Only Access to Office 365 Tenant
SPO_AppSecret Value of Client Secret created in Step 1: Setup App Only Access to Office 365 Tenant

Click Save

Step 7 - Create Site Script

Site script JSON will look like below. Refer to the attached site-script-flow.json

{
"$schema": "schema.json",
"actions": [
{
"verb": "triggerFlow",
"url": "[paste the workflow trigger URL here]",
"name": "Apply Template",
"parameters": {
"event":"",
"product":""
}
}
],
"bindata": {},
"version": 1
}

Open PowerShell.

Run the below commands

Connect-SPOService -Url "https://[tenant]-admin.sharepoint.com"
Get-Content .\site-script-flow.json -Raw | Add-SPOSiteScript -Title "PnP Flow Site Script"

Note down Script ID to register with Site Design

Step 8 - Create Site Design

Open PowerShell.

Run the below commands

Add-SPOSiteDesign -Title "Site with flow" -SiteScripts [ID of the Site Script] -WebTemplate "64"

Step 9 - Verify the results

To test the entire implementation,

Create new site in SharePoint tenant.
Click Team site
Select design Site with flow
Fill in the site name
Click Next
Observe site design getting applied to site
Click View updated site.
Verify Run history of MS Flow is succeded.
Open Azure queue and see the message in the queue
Look at the SharePoint site. It should have provisioning changes applied. For example HomePnP.aspx, in this case in "Site Pages" library.

Summary

Site designs can be extended using MS Flow to perform the actions not supported natively by Site scripts and overcome the 30 cumulative actions limitation.

SPO_AppId	Value of Client ID created in Step 1: Setup App Only Access to Office 365 Tenant
SPO_AppSecret	Value of Client Secret created in Step 1: Setup App Only Access to Office 365 Tenant