Condition to see if a File exists within a folder

[SamMartin]

Hi community!

I have been making a flow that Gets the last 25 emails in a folder, uses substring to get a certain part of the body of the email, then checks a file location using the substring as the end of the file path to see if the attachment on the email already exists or not, and if not creates the file using the attachment name and attachment content. I don't know why is isn't working!!! I have done everything in my power to try and figure it out but cannot. I have even added a step to create the file if the list files in folder does not work, but it seems to do that step every-time. I have attached photos of the flow, let me know if you need anymore info 🙂 The create file actions work as they do create them, the sub string works as it gets the correct string. It seems to just be the condition.

  

[creativeopinion · Accepted solution]

@SamMartin The logic in your flow needs some adjusting. The nested Apply to Each actions aren't necessary. 

Instead, it would be more efficient to collect the substrings from your all emails first than

loop through those to check if a file exists. Remember to rename your actions to keep things organized.

Get Emails

In the advanced option of the Get Emails (V3) action you can specify the top count. This will limit the number of emails returned to the number you input here. I would recommend putting a low number here while you are building and testing your flow. The max number of emails this action can return at a time is 25. 

Select No for the Fetch Only Unread Messages—if you want to return messages that have already be read in your inbox. Otherwise, this action will only look for unread emails. You can include attachments as well.

If you only want to return emails with attachments—you'll need to select Yes for the Only with Attachments dropdown. 

Loop through Each Email

Add an Apply to Each action and insert the value output from the Get Emails (V3) action. This action will loop through each email. 

Get Substring

You can use the substring action or an expression in a Compose action—I'll use a Compose action and an expression.

Add a Compose action to your flow.

In the Expression tab, enter the string() function. 

Click on the Dynamic content tab and insert the body dynamic content from the Get Emails (V3) action into the string() function.

Place your cursor at the start of the expression by pressing the up arrow key and type in substring with an opening bracket.

substring(

Go to the end of the expression by pressing the down arrow key and add a comma and the start index integer—922 in your case. A tooltip will appear above indicating which parameter the expression is expecting.

Add another comma and the length integer—6 in your case.

Add a closing bracket and run a test. Verify the outputs are what you expect.

Check if File Exists

I'm using a Get files (properties only) action in my case—here you can insert your List Files In Folder action. I'm using a Filter Query to limit the items returned to files only as this particular action does return folders as well. 

Count Files Returned

For troubleshooting purposes, add a Compose action with an expression to return the number of files returned from your action. 

Use the length() function and insert the values dynamic content from the action above.

Run a test.

Get File Names of Files in Folder

Add a Select action to your flow. Insert the Value dynamic content from the Get files (properties only) action. 

Click on the icon to change from map to text mode.

Insert the File name with extension dynamic content from the Get files (properties only) action. This action will return an array of all the file names of the files in the specified folder.

Next, add a Join action. Insert the output from the Select action above. In the Join with field insert a comma with a space after it.

This action will convert the array of file names into a string of file names. Run a test. 

Filter Array on Attachments

The Attachments dynamic content returns an array of attachments. Use the Filter Array action to check if any of those attachments exist in your folder already. This is more efficient than looping through each attachment and running a condition check to see if the file exists. 

To learn more about how to use the Filter Array action, please refer to this recent YT Tutorial I uploaded.

In the From field, insert the Attachments dynamic content.

In the first value field, insert the output from the Join action (the one that has the attachment file names from your folder in a comma separated string).

Change the operator to does not contain.

In the second value field, insert the Attachments Name dynamic content from the Get Emails (V3) action. Important: Power Automate will automatically nest the Filter Array action inside another Apply to Each action. This is NOT required. 

Drag your Filter Array action outside of the Apply to Each action that was automatically added—delete it.

Add a Compose action to store the number of items in your Filter Array action. Run a test.

In my example, I have an email with 3 attachments. One of those attachments already exist in my folder.

The Filter Array action essentially cross-checks the file names of my attachments in the current email (being looped through) to see if those files exist already. If they do, the Filter Array action will filter that item/those items out.

The Filter Array action filtered out that item, returning only two files. 

Group Actions (optional)

To keep things organized, you can use a Scope action to group actions together. This will allow you to quickly collapse actions with a single click. This is totally optional—however I prefer to use them to keep my flows organized.

Condition Check

Add a Condition action. In the first value field, insert the output from the Compose action with the Filtered Files count.

Change the operator to is not equal to and enter 0 into the second value field. This condition will check if there are any filtered files before continuing on with your flow. Add the rest of your actions to the YES branch.

Loop Through Filtered Array

Add an Apply to Each action to loop through your Filtered Array of attachments.

The next step is optional. I'll be inserting a Compose action to store the Attachment ID, Name and Content from the Filter array action. Alternatively, you can insert the expressions right into the Create File action—I prefer to use Compose actions.

Compose Dynamic Content from Filter Array

Add a Compose action to store the Attachment ID. Alternatively you can insert the expression directly into the Get Attachment (V2) action. I prefer to use Compose actions.

If you look at the output of the Filter Array action you can access the dynamic content from it by using an expression and referencing a key. The key is the red text between the quote marks.

Please refer to this section of my YT Tutorial that covers how to return the dynamic content from the Filter Array action. 

To return the Attachment Id, you'll need to use the item() function. Add a question mark and square brackets with single quotes.

item()?['']

In between the single quotes insert the key (red text between double quotes).

Run a test. The

Repeat this step for the name and attachment content (contentBytes).

Create File(s)

Add a Create File action. I'm using the Create File SharePoint action—you'll need to select the proper action for your flow requirements. 

In the folder path—I've inserted the output from the Compose action with the substring. 

In the File Name field, I've inserted the output from the Compose action that has the Attachment Name. For the File Content field, I've inserted the output from the Compose action that has the Attachment Content.

Run a test. The two attachments returned from the Filter Array action have been created.

I have a whole tutorial on how to save attachments from email onto SharePoint—you can reference that tutorial as well. Most of the concepts covered above are also covered in that tutorial.

Hope this helps!

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[SamMartin]

Hi @creativeopinion  thanks for looking into this with me 🙂

I notice using this it will not loop through each of the emails it retrieves in the Get Emails V3, therefore would it need to be nested in a loop so that it moves onto the next email and gets the next substring? 

There should be 10 different values here but this value is the one on the first email, it isn't getting the rest from the other 10 emails?

[creativeopinion]

@SamMartin This select action doesn't require to be nested inside an Apply to Each loop. The From value is the value dynamic content from the Get emails (V3) action—essentially the items returned from that action. 

You should check your Get Emails (V3) action to ensure the top count of emails being returned as well as only including email with attachments.

I've limited my top count to 3 for testing purposes. I would recommend you do the same to speed up your flow runs while you are building and testing your flow. 

Will be adding additional instructions shortly... 

[creativeopinion]

@SamMartin I've updated the instructions. I realized after reviewing your requirements again that I made an error in my original recommendation. I've updated the original post. Please take a look. Hope it helps!

[SamMartin]

@creativeopinion Thanks for this massively! This worked, had to do a bit of tweaking to adjust it for my file system but it was very inline with your method. The only thing I noticed was when I tried using a compose the get the substring in the array it would still only result with the first emails substring 3 times rather than the 3 emails substrings, I changed it to the substring action and it worked perfectly 🙂 I have marked as solution.