JS:Rest File Upload Sharepoint

jsRestFileUplodeSharepoint.js

'use strict';

//*These Variables are to store Application URL and Sharepoint Web URL
var appWebUrl, hostWebUrl;


//*This step is to check that FileReader function is supported in the Browser In which REST File Uplode is being done.
jQuery(document).ready(function () {

    // Check for FileReader API (HTML5) support.
    if (!window.FileReader) {
        alert('This browser does not support the FileReader API.');
    }

    // Get the add-in web and host web URLs.
    appWebUrl = decodeURIComponent(getQueryStringParameter("SPAppWebUrl"));
    hostWebUrl = decodeURIComponent(getQueryStringParameter("SPHostUrl"));
});


//*This is the Function from where Execution of the Program starts.
/*
	When you will click on the Uplode Buttom This function will kick in to action and
	all execution will start from here.
*/
// Upload the file.
// You can upload files up to 2 GB with the REST API.
function uploadFile() {

    // Define the folder path for this example.
    var serverRelativeUrlToFolder = '/shared documents';

    // Get test values from the file input and text input page controls.
    // The display name must be unique every time you run the example.
    var fileInput = jQuery('#getFile');//* Here the File is Added
    var newName = jQuery('#displayName').val();//* Name of file

    // Initiate method calls using jQuery promises.
    // Get the local file as an array buffer.
    var getFile = getFileBuffer();//* This function will return File data stored in an FileBuffer as ArrayBuffer
	/*
	From Here it Deals with what to deal when File is stored in Array Buffer
	*/
    getFile.done(function (arrayBuffer) {

        // Add the file to the SharePoint folder.
		/*This Function will send the a REST query to save the file to a desired location 
		and return jQuery.ajax object.
		*/
        var addFile = addFileToFolder(arrayBuffer);
		//When successfully updated file
        addFile.done(function (file, status, xhr) {

            // Get the list item that corresponds to the uploaded file.
			/*
			Next Operation is to Get the Item which is just being uploded to Site vai REST
			*/
            var getItem = getListItem(file.d.ListItemAllFields.__deferred.uri);//GET ITEM
            getItem.done(function (listItem, status, xhr) {

                // Change the display name and title of the list item.
				/*
				When Getting Item is Successful then Update the Item with New values.
				*/
                var changeItem = updateListItem(listItem.d.__metadata);//Update Function
                changeItem.done(function (data, status, xhr) {//On Success
                    alert('file uploaded and updated');
                });
                changeItem.fail(onError);
            });
            getItem.fail(onError);
        });
        addFile.fail(onError);
    });
    getFile.fail(onError);

    // Get the local file as an array buffer.
    function getFileBuffer() {
        var deferred = jQuery.Deferred();
        var reader = new FileReader();
        reader.onloadend = function (e) {
            deferred.resolve(e.target.result);
        }
        reader.onerror = function (e) {
            deferred.reject(e.target.error);
        }
        reader.readAsArrayBuffer(fileInput[0].files[0]);
        return deferred.promise();
    }

    // Add the file to the file collection in the Shared Documents folder.
    function addFileToFolder(arrayBuffer) {

        // Get the file name from the file input control on the page.
        var parts = fileInput[0].value.split('\\');
        var fileName = parts[parts.length - 1];

        // Construct the endpoint.
        var fileCollectionEndpoint = String.format(
            "{0}/_api/sp.appcontextsite(@target)/web/getfolderbyserverrelativeurl('{1}')/files" +
            "/add(overwrite=true, url='{2}')?@target='{3}'",
            appWebUrl, serverRelativeUrlToFolder, fileName, hostWebUrl);

        // Send the request and return the response.
        // This call returns the SharePoint file.
        return jQuery.ajax({
            url: fileCollectionEndpoint,
            type: "POST",
            data: arrayBuffer,
            processData: false,
            headers: {
                "accept": "application/json;odata=verbose",
                "X-RequestDigest": jQuery("#__REQUESTDIGEST").val(),
                "content-length": arrayBuffer.byteLength
            }
        });
    }

    // Get the list item that corresponds to the file by calling the file's ListItemAllFields property.
    function getListItem(fileListItemUri) {

        // Construct the endpoint.
        // The list item URI uses the host web, but the cross-domain call is sent to the
        // add-in web and specifies the host web as the context site.
        fileListItemUri = fileListItemUri.replace(hostWebUrl, '{0}');
        fileListItemUri = fileListItemUri.replace('_api/Web', '_api/sp.appcontextsite(@target)/web');
        
        var listItemAllFieldsEndpoint = String.format(fileListItemUri + "?@target='{1}'",
            appWebUrl, hostWebUrl);

        // Send the request and return the response.
        return jQuery.ajax({
            url: listItemAllFieldsEndpoint,
            type: "GET",
            headers: { "accept": "application/json;odata=verbose" }
        });
    }

    // Change the display name and title of the list item.
    function updateListItem(itemMetadata) {

        // Construct the endpoint.
        // Specify the host web as the context site.
        var listItemUri = itemMetadata.uri.replace('_api/Web', '_api/sp.appcontextsite(@target)/web');
        var listItemEndpoint = String.format(listItemUri + "?@target='{0}'", hostWebUrl);

        // Define the list item changes. Use the FileLeafRef property to change the display name. 
        // For simplicity, also use the name as the title.
        // The example gets the list item type from the item's metadata, but you can also get it from the
        // ListItemEntityTypeFullName property of the list.
        var body = String.format("{{'__metadata':{{'type':'{0}'}},'FileLeafRef':'{1}','Title':'{2}'}}",
            itemMetadata.type, newName, newName);

        // Send the request and return the promise.
        // This call does not return response content from the server.
        return jQuery.ajax({
            url: listItemEndpoint,
            type: "POST",
            data: body,
            headers: {
                "X-RequestDigest": jQuery("#__REQUESTDIGEST").val(),
                "content-type": "application/json;odata=verbose",
                "content-length": body.length,
                "IF-MATCH": itemMetadata.etag,
                "X-HTTP-Method": "MERGE"
            }
        });
    }
}

// Display error messages. 
function onError(error) {
    alert(error.responseText);
}

// Get parameters from the query string.
// For production purposes you may want to use a library to handle the query string.
function getQueryStringParameter(paramToRetrieve) {
    var params = document.URL.split("?")[1].split("&");
    for (var i = 0; i < params.length; i = i + 1) {
        var singleParam = params[i].split("=");
        if (singleParam[0] == paramToRetrieve) return singleParam[1];
    }
}