I created my blog series on SharePoint BCS quite some time ago in order to illustrate how easy it is to access data outside of SharePoint and present it within a list or document library. I have been meaning for quite some time to demonstrate how writing code for external lists\libraries is very similar to writing code for internal lists\libraries. Today I am going to start a new three part series on SharePoint BCS development by showing you how you can enhance your solutions using PowerShell to access data in external lists. The posts aren’t going to be too in-depth, but meant to get you started. I hope to build on them later and post a series on creating an entire solution around BCS.
Using PowerShell to Manage Data in Internal Lists
With SharePoint PowerShell you are basically using the server object model for development. So this means you have access to the methods and processes utilised by this system. What you’ll notice is that code to perform inserts, updates, reads and deletions is pretty much exactly the same. Where the code differs between internal and external is actually around accessing the item to be updated, read or deleted.
To illustrate I have created a script that performs an insert, update, read and delete. To show you what’s happening here’s the config for the code:
<List ParentSiteURL="http://teams.drevsp2016.com/bcs/" ListName="DemoCode">
<ListItems>
<ListItem Action="Insert" ID="">
<Fields>
<Field Title="Title" Value="New Item"/>
<Field Title="Description" Value="This Field was created using PowerShell and SOM"/>
</Fields>
</ListItem>
<ListItem Action="Update" ID="1">
<Fields>
<Field Title="Title" Value="BCS is Really Awesome"/>
<Field Title="Description" Value="This Field was UPDATED using PowerShell and SOM"/>
</Fields>
</ListItem>
<ListItem Action="Update" ID="3">
<Fields>
<Field Title="Title" Value="Dave is a great speaker and should get a great review"/>
<Field Title="Description" Value="This Field was UPDATED using PowerShell and SOM"/>
</Fields>
</ListItem>
<ListItem Action="Read" ID="4">
<Fields>
<Field Title="Title" Value=""/>
<Field Title="Description" Value=""/>
</Fields>
</ListItem>
<ListItem Action="Delete" ID="2">
<Fields>
<Field Title="" Value=""/>
<Field Title="" Value=""/>
</Fields>
</ListItem>
</ListItems>
</List>
As you can see the code should insert a new item, update two, read a third and finally delete. The code is pretty straight forward:
foreach($xmlItem in $xmlList.ListItems.ListItem)
{
switch($xmlItem.Action)
{
"Insert"
{
$newListItem = $spList.AddItem();
foreach($xmlField in $xmlItem.Fields.Field)
{
$newListItem[$xmlField.Title] = $xmlField.Value;
}
#Update the new list item
$newListItem.Update();
break;
}
"Update"
{
$updateListItem = $spList.GetItemByID($xmlItem.ID);
foreach($xmlField in $xmlItem.Fields.Field)
{
$updateListItem[$xmlField.Title] = $xmlField.Value;
}
#Update the new list item
$updateListItem.Update();
break;
}
"Read"
{
$readListItem = $spList.GetItemByID($xmlItem.ID);
foreach($xmlField in $xmlItem.Fields.Field)
{
write-host("The Value of field '{0}' is '{1}'" -f $xmlField.Title, $readListItem[$xmlField.Title]) -ForegroundColor Cyan;
}
break;
}
"Delete"
{
$deleteListItem = $spList.GetItemByID($xmlItem.ID);
$deleteListItem.Delete();
Write-Host("Successfully deleted item #{0}" -f $xmlItem.ID) -ForegroundColor Magenta;
break;
}
}
}
Using the following list:
And running the above script:
We end up with the result:
Using PowerShell to Update External Lists
The code is almost identical. What actually changes is the code used for finding the items we want to update. We also have to define the ServiceContext scope to process the transactions. External list manipulation requires the scope to import the data catalogue (more information can be found here). First the config to see what the plan is:
<Lists>
<List ParentSiteURL="http://teams.drevsp2016.com/bcs/" ParentSiteColURL="http://teams.drevsp2016.com" ListName="Asset List">
<ListItems>
<ListItem Action="Insert" AssetID="">
<Fields>
<Field Title="Type" Value="Printer"/>
<Field Title="Make" Value="Brother"/>
<Field Title="Model" Value="MJD-2500"/>
<Field Title="Details" Value="This Item Added Via PowerShell"/>
</Fields>
</ListItem>
<ListItem Action="Update" AssetID="1">
<Fields>
<Field Title="Location" Value="Denver"/>
<Field Title="Details" Value="This Field was UPDATED using PowerShell and SOM"/>
</Fields>
</ListItem>
<ListItem Action="Update" AssetID="9">
<Fields>
<Field Title="Type" Value="Monitor"/>
<Field Title="Make" Value="Samsung"/>
<Field Title="Model" Value="30inch"/>
<Field Title="Details" Value="This Field was UPDATED using PowerShell and SOM"/>
</Fields>
</ListItem>
<ListItem Action="Read" AssetID="9">
<Fields>
<Field Title="Type" Value=""/>
<Field Title="Make" Value=""/>
<Field Title="Model" Value=""/>
<Field Title="Details" Value=""/>
</Fields>
</ListItem>
<ListItem Action="Delete" AssetID="22">
<Fields>
<Field Title="" Value=""/>
<Field Title="" Value=""/>
</Fields>
</ListItem>
</ListItems>
</List>
</Lists>
Then using the code:
foreach($xmlList in $testExternalList.Config.Lists.List)
{
#Define the SPServiceContextScope to access the Data Catalog
$ctx = get-SPServiceContext $xmlList.ParentSiteColURL;
$scope = new-object Microsoft.SharePoint.SPServiceContextScope $ctx
$spWeb = Get-SPWeb $xmlList.ParentSiteURL;
$spList = $spWeb.Lists[$xmlList.ListName];
foreach($xmlItem in $xmlList.ListItems.ListItem)
{
switch($xmlItem.Action)
{
"Insert"
{
$newListItem = $spList.Items.Add();
foreach($xmlField in $xmlItem.Fields.Field)
{
$newListItem[$xmlField.Title] = $xmlField.Value;
}
#Update the new list item
$newListItem.Update();
Write-Host "Successfully inserted new item" -ForegroundColor Cyan;
break;
}
"Update"
{
$updAssetID = [int]$xmlItem.AssetID;
#Use PowerShell query to find the item to update
$updateListItem = $spList.Items | Where-Object {$_["AssetID"] -eq $updAssetID};
foreach($xmlField in $xmlItem.Fields.Field)
{
$updateListItem[$xmlField.Title] = $xmlField.Value;
}
#Update the new list item
$updateListItem.Update();
Write-Host ("Updated AssetID: {0}" -f $updAssetID) -ForegroundColor Green;
break;
}
"Read"
{
$readAssetID = [int]$xmlItem.AssetID;
#Use PowerShell query to find the item to update
$readListItem = $spList.Items | Where-Object {$_["AssetID"] -eq $readAssetID};
foreach($xmlField in $xmlItem.Fields.Field)
{
write-host("The Value of field '{0}' is '{1}'" -f $xmlField.Title, $readListItem[$xmlField.Title]) -ForegroundColor Cyan;
}
break;
}
"Delete"
{
$delAssetID = [int]$xmlItem.AssetID;
#Use PowerShell query to find the item to update
$deleteListItem = $spList.Items | Where-Object {$_["AssetID"] -eq $delAssetID};
$deleteListItem.Delete();
Write-Host("Successfully deleted item #{0}" -f $delAssetID) -ForegroundColor Magenta;
break;
}
}
}
}
Notice in the code above that we are using a pipe to gather the data. One thing to note with External Lists is they do not have a numerical ID field. However, in this case we are grabbing the ID field of the Asset so we can search on the AssetID of the item.
We then update the following list:
by running the code:
And receive the following updated list:
That’s the basics of updating an External List with PowerShell. In the next post I will cover updating using CSOM.
Thanks for Reading!
Comments