Need help with content types in http request

Answered

Christoph Käferböck

• Created February 26, 2024 14:22

Hi together,

I need your help regarding a http request for getting file content.

The regarding action can be found in our solution reccomglobaldata_dev in the list "Vorgänge", Disp-Form, action "Weiterleiten" and also in the file attached.

 

I want to get the content of an attachment file of a list element and add it as an attachment file in an other list element (similar to function "forwarding" when writing an email). I used an http request for getting the file content, but unfortunately the content has many errors. I guess the reason can be found in the content-type used. Unfortunately i have just little experience with http-requests. Can somebody tell me how to setup such an http request/workflow to work properly?

Best regards,

Christoph

0

• Official comment

  

  skybow Support

  • February 28, 2024 16:51
  • Edited

  Hi Christoph,

  This example demonstrates how to copy list items attachments to a new item from another SharePoint list.
  In order to archive this, I customized the display form of List1, and added a new button with the following actions configuration:

  
  1) Variables:

  SourceListTitle - title of source list
  SourceItemID - ID of source list item
  TargetListTitle - the title of the target list, where new item will be added
  TargetListItemID - ID of new item, that should be attachments copied to. Initially value is empty, it will be set after the item is created

  

  2) Add List item

  In this step, we add a new item to List2

  
  3) Set variable
  It updates the value for TargetListItemID variable, it will be a newly created item ID from the previous step.

  
  4) Send HTTPRequest - GetAttachments
  Load a list of attachments for the item.

  URL: [[@Web.ServerRelativeUrl]]/_api/web/lists/getbytitle('[[@Variables.SourceListTitle]]')/items([[@Variables.SourceItemID]])/AttachmentFiles

  Headers:

  Accept: application/json;odata=verbose

   The resonse will have the following JSON format :
  {
    d : {
      results: [{
        FileName: "file1.txt",
        ServerRelativeUrl: "/sites/site1/test-solution2/Lists/List1/Attachments/1/file1.txt"
      },
      {
        FileName: "file2.txt",
        ServerRelativeUrl: "/sites/site1/test-solution2/Lists/List1/Attachments/1/file2.txt"
      }]
    }
  }

  
  5) Next steps I go through all attachments and copy them one by one synchronously

  Script:

  //Read the attachment file content
  function downloadfile(downloadUrl) {
      return new Promise(resolve => {
          var xhr = new XMLHttpRequest();
          xhr.open('GET', downloadUrl, true);
          xhr.setRequestHeader('binaryStringResponseBody', 'true');
          xhr.responseType = 'arraybuffer';
          xhr.onload = function (e) {
              if (this.status == 200) {
                  var arrayBuffer = this.response;
                  resolve(arrayBuffer);
              }
          };
          xhr.send();
      });
  }
  
  //Uploads the attachment file to list item
  function uploadAttachment(uploadUrl, arrayBuffer, fileName) {
      return new Promise((resolve, reject) => {
          jQuery.ajax({
              url: uploadUrl,
              type: "POST",
              data: arrayBuffer,
              processData: false,
              contentType: "application/json;odata=verbose",
              headers: {
                  "accept": "application/json;odata=verbose",
                  "X-RequestDigest": jQuery("#__REQUESTDIGEST").val()
              }
          }).done(postData => {
              console.log("Uploaded file attachment: " + fileName);
              resolve();
          }).fail(function (jqXHR, errorText) {
              console.error(errorText);
              reject("File attachment is not uploaded: " + fileName);
          });
      });
  }
  
  //Copy attachment from source item to the newly created item of target list
  function copyAttachment(fileName) {
      return downloadfile([[@Web.ServerRelativeUrl]]+ "/_api/web/lists/getbytitle('" + [[@Variables.SourceListTitle]]+ "')/items(" + [[@Variables.SourceItemID]]+ ")/AttachmentFiles/getbyfilename('" + fileName + "')/$value')")
          .then(arrayBuffer => {
              return uploadAttachment([[@Web.ServerRelativeUrl]]+ "/_api/web/lists/GetByTitle('" + [[@Variables.TargetListTitle]]+ "')/items(" + [[@Variables.TargetListItemID]]+ ")/AttachmentFiles/add(FileName='" + fileName + "')", arrayBuffer, fileName)
          });
  }
  
  //A list of file names of item attachments
  var attachmentFileNames = [[@Actions.Send_HTTP_request_GetAttachments.ResponseBody]].d.results.map(attachment => attachment.FileName);
  
  //Copies all attachments synchronously one by one
  function uploadNextAttachment() {
      if (attachmentFileNames.length == 0) {
          return Promise.resolve();
      }
      else {
          //Get first attachment file name and remove it from a list
          var fileName = attachmentFileNames.shift();
          return copyAttachment(fileName).then(() => {
              return uploadNextAttachment();
          });
      }
  }
  
  return uploadNextAttachment();

   

  Best regards,

  YuriyStetsyuk
• 

  Christoph Käferböck

  • February 28, 2024 09:55

  Hi Yuriy,

  I implemented your solution and it worked from the first moment on as expected. Many thanks to you!

  Christoph

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