{"id":505,"date":"2021-04-12T03:43:48","date_gmt":"2021-04-12T03:43:48","guid":{"rendered":"https:\/\/portfolio.accrualhub.com\/powergi2\/?p=505"},"modified":"2025-09-11T19:54:56","modified_gmt":"2025-09-11T19:54:56","slug":"azure-function-to-combine-pdf-files","status":"publish","type":"post","link":"https:\/\/powergi.net\/es\/blog\/azure-function-to-combine-pdf-files\/","title":{"rendered":"Azure Function to combine PDF files"},"content":{"rendered":"\t\t
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We will create an Azure Function that will merge PDF documents stored in a container of our storage account in Azure, this function will receive the file names to be merged\/combined in the parameters of the URL and they will be separated by commas.<\/p>\n\n

Below is an example of the POST request that the code presented in this blog will be able to process.<\/p>

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From vision to execution<\/p>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Whether you're just starting or scaling automation, we help turn your ideas into impactful solutions.<\/p>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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\"\"<\/figure>\n\n

Set up your project<\/h3>\n\n
    \n
  1. Create an azure function project and use the HTTP Trigger<\/li>\n
  2. Make sure you install the below packages before getting started with coding<\/li>\n<\/ol>\n\n
    \"\"<\/figure>\n\n

    Create the Function code<\/h3>\n\n

    We are ready to start writing code. We need two files:<\/p>\n\n

    ResultClass.cs<\/strong> \u2013 will return the file(s) merged as list<\/p>\n\n

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    using System;\nusing System.Collections.Generic;\n\nnamespace FunctionApp1\n{\n\n    public class Result\n    {\n\n        public Result(IList newFiles)\n        {\n            this.files = newFiles;\n        }\n\n        public IList files { get; private set; }\n    }\n}<\/code><\/pre>\n<\/div>\n<\/div>\n\n
    Function1.cs<\/strong> \u2013 Code that will receive the file names in the URL, grab them from the Storage account, merge them into one and return a download URL<\/p>\n\n
    using System;\nusing System.Collections.Generic;\nusing System.IO;\nusing System.Net.Http;\nusing System.Threading.Tasks;\nusing Microsoft.AspNetCore.Http;\nusing Microsoft.AspNetCore.Mvc;\nusing Microsoft.Azure.WebJobs;\nusing Microsoft.Azure.WebJobs.Extensions.Http;\nusing Microsoft.Extensions.Logging;\nusing Microsoft.Extensions.Configuration;\nusing Microsoft.WindowsAzure.Storage.Blob;\nusing Newtonsoft.Json;\nusing PdfSharp.Pdf;\nusing PdfSharp.Pdf.IO;\n\nnamespace FunctionApp1\n{\n    public class Function1\n    {\n\n        static Function1()<\/span><\/strong>\n        {\n\n            \/\/ This is required to avoid the \"No data is available <\/span>                        for encoding 1252\" exception when saving the PdfDocument<\/span>\nSystem.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);\n\n        }\n\n        [FunctionName(\"Function1\")]\n        public async Task SplitUploadAsync(\n            [HttpTrigger(AuthorizationLevel.Anonymous, \"post\", Route = null)] HttpRequestMessage req,\n            \/\/container where files will be stored and accessed for retrieval. in this case, it's called temp-pdf\n<\/span>            [Blob(\"temp-pdf\", Connection = \"\")] CloudBlobContainer outputContainer,\n            ILogger log)\n        {\n            \/\/get query parameters\n<\/span>\n            string uriq = req.RequestUri.ToString(); \n            string keyw = uriq.Substring(uriq.IndexOf('=') + 1);\n\n            \/\/get file name in query parameters\n<\/span>            String fileNames = keyw.Split(\"mergepfd&filenam=\")[1];\n\n            \/\/split file name<\/span>\n            string[] files = fileNames.Split(',');\n\n            \/\/process merge<\/span>\n            var newFiles = await this.MergeFileAsync(outputContainer, files);\n\n            return new Result(newFiles);\n\n        }\n\n        private async Task<IList> MergeFileAsync(CloudBlobContainer container, string[] blobfiles)<\/span><\/strong>\n        {\n            \/\/init instance<\/span>\n            PdfDocument outputDocument = new PdfDocument();\n\n            \/\/loop through files sent in query<\/span>\n            foreach (string fileblob in blobfiles)\n            {\n                String intfile = $\"\" + fileblob;\n\n                \/\/ get file<\/span>\n                CloudBlockBlob blob = container.GetBlockBlobReference(intfile);\n\n                using (var memoryStream = new MemoryStream())\n                {\n                    await blob.DownloadToStreamAsync(memoryStream);\n\n                    \/\/get file content<\/span>\n                    string contents = blob.DownloadTextAsync().Result;\n                   \n                    \/\/open document<\/span>\n                    var inputDocument = PdfReader.Open(memoryStream, PdfDocumentOpenMode.Import);\n\n                    \/\/get pages<\/span>\n                    int count = inputDocument.PageCount;\n                    for (int idx = 0; idx < count; idx++)\n                    {\n                        \/\/append<\/span>\n                        outputDocument.AddPage(inputDocument.Pages[idx]);\n                    }\n\n\n                }\n            }\n\n\n            var outputFiles = new List();\n            var tempFile = String.Empty;\n\n            \/\/call save function to store output in container<\/span>\n            tempFile = await this.SaveToBlobStorageAsync(container, outputDocument);\n\n            outputFiles.Add(tempFile);\n\n            \/\/return file(s) url<\/span>\n            return outputFiles;\n        }\n\n        private async Task SaveToBlobStorageAsync(CloudBlobContainer container, PdfDocument document)<\/span><\/strong>\n        {\n\n            \/\/file name structure<\/span>\n            var filename = $\"merge-{DateTime.Now.ToString(\"yyyyMMddhhmmss\")}-{Guid.NewGuid().ToString().Substring(0, 4)}.pdf\";\n\n            \/\/ Creating an empty file pointer<\/span>\n            var outputBlob = container.GetBlockBlobReference(filename);\n\n            using (var stream = new MemoryStream())\n            {\n                \/\/save result of merge<\/span>\n                document.Save(stream);\n                await outputBlob.UploadFromStreamAsync(stream);\n            }\n\n            \/\/get sas token<\/span>\n            var sasBlobToken = outputBlob.GetSharedAccessSignature(new SharedAccessBlobPolicy()\n            {\n                SharedAccessExpiryTime = DateTime.UtcNow.AddMinutes(5),\n                Permissions = SharedAccessBlobPermissions.Read\n            });\n\n            \/\/return sas token<\/span>\n            return outputBlob.Uri + sasBlobToken;\n        }\n    }\n}\n\n<\/code><\/pre>\n\n
    Our expertise in Power Platform consulting services<\/strong><\/a> helps transform ideas into impactful digital solutions, merging efficiency with innovation. Whether it\u2019s optimizing your workflow or automating routine tasks through Microsoft Power Platform, our tailored consultancy ensures seamless execution.<\/p>\n
    Create Azure Function<\/h3>\n\n
    Create the resource in Azure for the Azure Function. Below you can see how I did the set up for my function<\/p>\n\n
    \"\"<\/figure>\n\n
    Publish your Code<\/h3>\n\n
    Now it\u2019s time to Publish our Function to the Azure service. Right click on your solution and select the \u201cPublish\u201d option.<\/p>\n\n
    Follow the instructions in the next screens, once you reach the Service Dependencies <\/strong>section, make sure that you select the storage account where your PDF documents to merge are saved<\/strong>. Also, double check that the right container name is used in the connection string.<\/p>\n\n
    In below screenshot you can see how I selected storageaccountazure8721 <\/em><\/strong>as the one that contains my \u201ctemp-pdf<\/em><\/strong>\u201d container. Note that this container can be the same where your Function is storing its files or it can a completely different.<\/p>
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    Free up your team\u2019s time and focus on strategic work with digital and robotic automation.<\/p>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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    \"\"<\/figure>\n\n
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    Make sure that the container name in the connection string exists in the Storage account you select in the dependency \u2013 in this case \u201ctemp-pdf\u201d<\/figcaption>\n<\/figure>\n\n
    Click publish and wait for the success confirmation from Visual Studio.<\/p>\n\n
    You\u2019re all set!<\/h3>\n\n
    All is ready. You can merge any number of pdf documents into one and get a link that will allow direct download of the merged file.<\/p>\n\n
    \"\"<\/figure>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"
    We will create an Azure Function that will merge PDF documents stored in a container of our storage account in Azure, this function will receive the file names to be merged\/combined in the parameters of the URL and they will be separated by commas. Below is an example of the POST request that the code […]<\/p>\n","protected":false},"author":2,"featured_media":2630,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"glossary_letter":"","footnotes":""},"categories":[32],"tags":[13,14,33],"class_list":["post-505","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-azure-cat","tag-automation","tag-azure_tag","tag-azure-function"],"glossary_letter":null,"rank_math_title":null,"rank_math_description":"How to use Azure Functions to merge PDF files automatically. An advanced technical integration solution for your business on the Power GI blog.","rank_math_focus_keyword":null,"_links":{"self":[{"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/posts\/505","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/comments?post=505"}],"version-history":[{"count":0,"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/posts\/505\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/media\/2630"}],"wp:attachment":[{"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/media?parent=505"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/categories?post=505"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/powergi.net\/es\/wp-json\/wp\/v2\/tags?post=505"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}