naveegator.in

Author: Naveen

  • Why we fail to prepare for disasters

    Considering the current COVID-19 pandemic, one of the best things I have read on why we failed to get a grasp on this.

    Part of the problem may simply be that we get our cues from others. In a famous experiment conducted in the late 1960s, the psychologists Bibb Latané and John Darley pumped smoke into a room in which their subjects were filling in a questionnaire. When the subject was sitting alone, he or she tended to note the smoke and calmly leave to report it. When subjects were in a group of three, they were much less likely to react: each person remained passive, reassured by the passivity of the others.

    As the new coronavirus spread, social cues influenced our behaviour in a similar way. Harrowing reports from China made little impact, even when it became clear that the virus had gone global. We could see the metaphorical smoke pouring out of the ventilation shaft, and yet we could also see our fellow citizens acting as though nothing was wrong: no stockpiling, no self-distancing, no Wuhan-shake greetings. Then, when the social cues finally came, we all changed our behaviour at once. At that moment, not a roll of toilet paper was to be found.

    Why we fail to prepare for disasters

    But at the end it gets scary, really scary.

    Because Covid-19 has spread much faster than HIV and is more dangerous than the flu, it is easy to imagine that this is as bad as it is possible to get. It isn’t. Perhaps this pandemic, like the financial crisis, is a challenge that should make us think laterally, applying the lessons we learn to other dangers, from bioterrorism to climate change. Or perhaps the threat really is a perfectly predictable surprise: another virus, just like this one, but worse. Imagine an illness as contagious as measles and as virulent as Ebola, a disease that disproportionately kills children rather than the elderly.

    What if we’re thinking about this the wrong way? What if instead of seeing Sars as the warning for Covid-19, we should see Covid-19 itself as the warning?

    Next time, will we be better prepared?

    Why we fail to prepare for disasters

    If COVID-19 is a warning, then what will the actual disaster look like?

  • Testing SPFx web part on Modern page – not on workbench

    For a long time I have been developing and testing my SPFx web part on workbench.aspx, which is a terrible option considering you only have limited screen space and you don’t get to see how your web part will look like once it is added to the page. Well, there is a way to test and debug your web part on Modern page.

    First, lets create sppkg package to deploy. For that, run the below commands.

    1. gulp clean
    2. gulp bundle
    3. gulp package-solution

    Note that I am not using the --ship option while running the bundle and package-solution tasks. This will give you a warning – [package-solution] This is not a production build (--ship or --production), therefore the "includeClientSideAssets" setting will be ignored. That’s what we want.

    Second, deploy your generated sppkg package to App Catalog and add web part to your page. When you load the page it will give error.

    This is because our code was not added to sppkg package as we did not use the --ship option.

    Third and final step, run gulp serve command and view the page. You can now test and debug the web part on the page.

  • TextEdit on Mac without formatting

    By default TextEdit shows rich text formatting options and saves file in RTF format. If you are looking for no-frills plain text editor, go to Format > Make Plain Text or press command + shift + T. The menu and key are essentially a toggle which switch between rich text and plain text. To make the plain text permanent go to TextEdit > Preferences… and select Plain text under the Format section.

  • Get count of items/files in list/document library in SharePoint Online with SPFx

    In SharePoint Online, when we view Site Contents, internally a call is made to the end point /_api/web/AppTiles to get the count of items/files in list/document library that the current site collection has. We can call this API in SPFx webpart to get these details. Below is the sample code.

    import { SPHttpClient, SPHttpClientResponse, SPHttpClientConfiguration } from '@microsoft/sp-http';

this.context.spHttpClient.get(`${this.context.pageContext.web.absoluteUrl}/_api/web/AppTiles`, SPHttpClient.configurations.v1)
  .then((response: SPHttpClientResponse) => {
    response.json()
      .then((responseJSON: any) => {
        console.log(responseJSON); // Gets all the list and document library details in JSON
      })
      .catch(error => {
        console.log(error);
      });
  })
  .catch(error => {
    console.log(error);
  });

    this.context refers to WebPartContext in the BaseClientSideWebPart class. The output will looks something like below JSON snippet. There is a lot of detail here which we can filter using $select. The attributes we require are Title and ChildCount.

    {
    "@odata.context": "https://mysite.sharepoint.com/sites/mysitecollection/_api/$metadata#AppTiles",
    "value": [
      {
        "@odata.type": "#SP.AppTile",
        "@odata.id": "https://mysite.sharepoint.com/sites/mysitecollection/_api/SP.AppTile0aab34a5-8bb4-4d5e-bac0-90841a08dd34",
        "@odata.editLink": "SP.AppTile0aab34a5-8bb4-4d5e-bac0-90841a08dd34",
        "AppId": "58de69fc-9e3f-4375-af44-205eeb452366",
        "AppPrincipalId": "",
        "AppSource": 0,
        "AppStatus": 4,
        "AppType": 0,
        "AssetId": "0;00bfea23-e717-4e80-bb17-d0c71b360101;101;",
        "BaseTemplate": 101,
        "ChildCount": 5,
        "ContentMarket": "",
        "CustomSettingsUrl": "",
        "Description": "",
        "IsCorporateCatalogSite": false,
        "LastModified": "4/26/2020 4:16 AM",
        "LastModifiedDate": "2020-04-26T11:16:27Z",
        "ProductId": "00cfea20-e900-4e80-aa17-d0c71b360101",
        "Target": "/sites/mysitecollection/Shared Documents/Forms/AllItems.aspx",
        "Thumbnail": "/_layouts/15/images/ltdl.png?rev=47",
        "Title": "Documents",
        "Version": "4"
      },
      ...
    ]
  }

  • Adding boilerplate code of React component in SPFx using VS Code

    React does not provide command line interface like Angular’s ng generate to create boilerplate code for React components. So you end up copying code from previous components and then modifying it. VS Code has snippets feature that we can leverage to create our own boilerplate code.

    To create your own snippets, go to User Snippets under File > Preferences (Code > Preferences on macOS) and select New Global Snippets file… Enter the name of the snippet file. You get a JSON file with below contents.

    {
	// Place your global snippets here. Each snippet is defined under a snippet name and has a scope, prefix, body and 
	// description. Add comma separated ids of the languages where the snippet is applicable in the scope field. If scope 
	// is left empty or omitted, the snippet gets applied to all languages. The prefix is what is 
	// used to trigger the snippet and the body will be expanded and inserted. Possible variables are: 
	// $1, $2 for tab stops, $0 for the final cursor position, and ${1:label}, ${2:another} for placeholders. 
	// Placeholders with the same ids are connected.
	// Example:
	// "Print to console": {
	// 	"scope": "javascript,typescript",
	// 	"prefix": "log",
	// 	"body": [
	// 		"console.log('$1');",
	// 		"$2"
	// 	],
	// 	"description": "Log output to console"
	// }
}

    Update the file with below code.

    {
	"SPFx React Component Template": {
		"prefix": "spfxtsx",
		"body": [
			"import * as React from 'react';" ,
			"export default class $1 extends React.Component<I$1Props, {}> {" ,
			"    constructor(props: I$1Props, public state: any) {" ,
			"        super(props);" ,
			"    }" ,
			"    public componentDidMount() {" ,
			"    }" ,
			"    public render(): React.ReactElement<I$1Props> {" ,
			"        return(<>" ,
			"        </>);" ,
			"    }" ,
			"}" ,
			"interface I$1Props {}"
		],
		"description": "Creates React component boilerplate code for SPFx"
	}
}

    The prefix (spfxtsx) here is the trigger text which will give you option to enter the snippet. $1 indicates tabstop and allows user to enter the name of the component, which is also used in name of props interface. In your tsx file when you start entering spfxtsx, it will populate with boilerplate code.

  • Uploading file with progress indicator in SPFx webpart using PnPJS in SharePoint

    SharePoint provides StartUpload, ContinueUpload and FinishUpload REST APIs to upload large files in chunk. PnPJS Library simplifies the implementation and we have to call only one method to upload file in chunks.

    To upload file in chunks in PnPJS, you call addChunked method by supplying a callback function which can be used to track the progress of the upload.

    sp.web.getFolderByServerRelativeUrl("/sites/naveegator/Shared%20Documents/")
    .files
    .addChunked(file.name, file,
        data => {
            // Here we update the progress by fetching data.blockNumber and data.totalBlocks
        }, true)
    }

    The third parameter in addChunked method is the callback function which provides ability to view in how many chunks the file are being uploaded (totalBlocks) and what is the current chunk (blockNumber) that is being uploaded. Using this information we can create progress bar to show percentage of file uploaded. Below is the React component in SPFx webpart. It uses PorgressIndicator from Office UI Fabric aka Fluent UI to display the progress bar.

    import * as React from 'react';
import { ProgressIndicator } from 'office-ui-fabric-react/lib/ProgressIndicator';
import { PrimaryButton } from 'office-ui-fabric-react';
import { sp } from "@pnp/sp/presets/all";

export default class UploadFile extends React.Component<IUploadFileProps, {}> {
  constructor(props: IUploadFileProps, public state: any) {
    super(props);

    this.state = {
      showProgress: false,
      progressLabel: "File upload progress",
      progressDescription: "",
      progressPercent: 0
    };
  }

  public render(): React.ReactElement<IUploadFileProps> {
    return (
      <>
        <input type="file" id="fileInput" /><br />
        <PrimaryButton text="Upload" onClick={this.uploadFile} /> <br />
        <ProgressIndicator
          label={this.state.progressLabel}
          description={this.state.progressDescription}
          percentComplete={this.state.progressPercent}
          barHeight={5} />
      </>
    );
  }

  private uploadFile = () => {
    let input = document.getElementById("fileInput") as HTMLInputElement;
    let file = input.files[0];
    let chunkSize = 40960; // Default chunksize is 10485760. This number was chosen to demonstrate file upload progress
    this.setState({ showProgress: true });
    sp.web.getFolderByServerRelativeUrl("/sites/naveegator/Shared%20Documents/")
      .files
      .addChunked(file.name, file,
        data => {
          let percent = (data.blockNumber / data.totalBlocks);
          this.setState({
            progressPercent: percent,
            progressDescription: `${Math.round(percent * 100)} %`
          });
        }, true,
        chunkSize)
      .then(r => {
        console.log("File uploaded successfully");
        this.setState({
          progressPercent: 1,
          progressDescription: `File upload complete`
        });
      })
      .catch(e => {
        console.log("Error while uploading file");
        console.log(e);
      });

  }
}

interface IUploadFileProps { }

    I have used chunkSize as 40960 so that I could display the progress bar for smaller sized file. For actual implementation you can omit that argument.

  • The Stockdale Paradox

    You must never ever ever confuse, on the one hand, the need for absolute, unwavering faith that you can prevail despite those constraints with, on the other hand, the need for the discipline to begin by confronting the brutal facts, whatever they are.

    The Stockdale Paradox

  • Passing function keys to Windows on Amazon WorkSpaces from MacBook with Touch Bar

    If you have MacBook with Touch Bar and you use it to access Windows on Amazon WorkSpaces then pressing fn + (function key) does not do anything on Windows. To get around this problem you have to update the below settings.

    Go to  > System Preferences… > Keyboard and update the settings Touch bar shows to F1, F2, etc. Keys.

    Downsides to this work around:

    • The function key F11 still goes to Mac and shows Desktop on Mac
    • You lose direct access to App Controls via Touch Bar

  • The Ellsberg Paradox

    You’re in a room with two large urns.

    The urns are covered so you can’t see inside them. But you know the urn on the left contains 50 white marbles and 50 black marbles. The urn on the right also contains 100 marbles, but the ratio of white to black marbles is unknown, with every ratio as likely as any other.

    […]

    What Ellsberg found is that people overwhelmingly choose to draw the ball from the urn with a known set of probabilities, rather than take a chance on the urn with an unknown ratio.

    This is despite the fact that the second urn could have better odds of drawing black marbles, like 99 to 1 or even 100 to no white marbles. Of course, the ratio in the unknown urn could also be tilted in the other direction. There’s no way of knowing.

    The fact is, the probability of drawing a black marble from either urn is identical.

    To verify this for yourself, just simplify the example.

    Instead of 100 marbles, imagine there are only 2. In the known urn, there is 1 black and 1 white. In the unknown urn, one-third of the time you’d be picking out of an urn with 2 black marbles. Another third of the time, 2 white marbles. And another third of the time, the urn has 1 of each.

    When you sum these probabilities up, you see that the chance of picking a black marble in the second urn is identical to picking one from the first urn: 50%.

    […]

    The takeaway? People exhibit strong aversion to ambiguity and uncertainty, meaning they have an inherent preference for the known over the unknown.

    The Ellsberg Paradox: Why You Don’t Take Risks and Settle for the Mediocre

    Thanks to Finshots for dropping this one in my inbox.

  • View all print screen keyboard shortcuts on Mac

    > System Preferences… > Keyboard > Shortcuts > Screenshots