blockchain – Can Hyperledger Fabric smart contracts be shared with peers outside of the channel where the contract was created?

I am a beginner in Hyperledger Fabric. From my understanding, smart contracts between individuals on a channel are signed and validated by peers within that channel. Can a smart contract between two peers be shared with a peer outside of that channel so that the third peer has “proof” of some of the details in the contract?

For context, I watched this video: (shouldn’t take more than 90 seconds of watching to get context to my question). In this scenario, if the Californian “Organic Market” wanted to sell the radishes to a consumer, can the market provide proof to the consumer that the radishes came from that specific grower in Chile? Additionally, can the organic market share proof of this without sharing all the individual details (wholesale price) of the contract? Thank you for your help.

equipment recommendation – How do I find fabric, tape, or materials that are black on infrared wavelengths?

I’m not exactly doing pro photography here; please forgive me. My baby monitor is mounted in a corner. It shines bright IR at night, and the walls are highly reflective, and I can barely see into the crib because the exposure is destroyed. I’ve tried a few things, including black sticky notes which might as well be white, blue painter’s tape that is currently on the wall because it’s better than nothing, and covering some of the emitters so they’d shine on the wall less, which maybe I didn’t do right but it didn’t help.

I haven’t yet tried my black t-shirts, but I’m not hopeful. Is there a cloth, tape, or something on the market that is dark on the IR spectrum?

plotting – How plot fabric of space time plots like these in Mathematica?

I would like to plot the blue deformed squared pattern rubber sheet surface like in this plot:

fabric space time

in Mathematica, with the modification that the ball or weight is concentrated in a single point with close or equal to zero volume.
Also I would like to plot several weights on the same rubber sheet, and then be able to retrieve the depth or $z$-coordinate, as well as the the given $x$ and $y$ coordinates.

Ultimately I am interested in how this relates to the Travelling Salesman Problem, because I have had the vague idea that given a set of points, say 10 or 20 points each of equal mass/weight, on a rubber sheet one would get a natural sorting of the points by their $z$-coordinates and thereby a solution to the travelling salesman problem.

The $x,y$-coordinates should be considered stationary as if the pointwise weigths are glued to the rubber sheet.

I don’t know how to tag this, but I am adding differential equations since I believe it has something to do with it.

what situation will lead the fabric network to a state fork

I have a question about in what situation it will lead the fabric network to a state fork?
I had met the state fork, see The mismatch of chaincode verison within fabric peers and MVCC_READ_CONFLICT error when update the fabric chaincode with composer, but I am not very certain about the reason. The offline peer will receive the txs and blocks from the orders and other peers when it is up.

spfx – Fabric UI Navbar components- How to swtich to horizontal layout?

I have done this using the CommandBar. I have created a Menu component and I set the items property from the WebPart.ts file (MenuWebPart.ts).

Below is the code for MenuWebPart.ts.

export default class MenuWebPart extends BaseClientSideWebPart<IMenuWebPartProps> {

  public render(): void {
    const element: React.ReactElement<IMenuProps> = React.createElement(
        items: (
          { name: 'Documents', url: '', key: 'key3', isExpanded: true },
          { name: 'Pages', url: '', key: 'key4' },
          { name: 'Notebook', url: '', key: 'key5' },
          { name: 'Long Name Test for ellipse', url: '', key: 'key6' }

    ReactDom.render(element, this.domElement);

And below is my code for the Menu.tsx file.

import * as React from 'react';
import { IMenuProps } from './IMenuProps';
import { CommandBar } from 'office-ui-fabric-react/lib/CommandBar';

export default class Menu extends React.Component<IMenuProps, {}> {
  constructor(props: IMenuProps) {
  public render(): React.ReactElement<IMenuProps> {
    const { items } = this.props;

    return (
        <CommandBar items={items} />

With this configuration, if you run your application, you will be able to see the menu in horizontal as follows.

enter image description here

Study – What are the differences between the different types of fabric backgrounds?

You might want to keep in mind that I've been out of the professional game for a while, and that I tend to shoot people "in the wild" these days, so I'm not fully up to date on the latest deals. I was really hoping to see some other information here from people who have more recent experience in a professional study environment, but here goes:


The canvas is extremely durable, but it is not particularly portable or storable. As a painted cloth, it is suitable for surface cleaning (wipe with a cloth or sponge); As a dyed fabric, it should allow light colors to get a bit dirtier over time and shadows to fade – dry cleaning, rather than washing, helps, just like dark storage in a sealed bag. White is not very white unless the canvas is painted (whitening only takes it a long way), so you need space to illuminate the background separately if you want something that is apparently White. (We will take as read that if you want "digitally white", you must overexpose none background.)

The canvas can be quite heavy; Even the lightest grades of cotton duck sold as "canvas" are in the 10-12oz range. region and painted finishes add considerably to that, so you need a sturdy mount (not necessarily a certified and approved official bottom mount set, but a pair of thumbtacks won't). It takes and shows wrinkles and folds, although over time they will relax until they are almost invisible if the canvas is dyed and without size (and can be ironed). The painted canvas really needs to be treated like a roll of paper; The binder in the paint (even if there is no visible paint film) makes wrinkles and wrinkles very prominent. It's a great thing for interchangeable stages or a durable seamless material, but they really do need to be kept hung or rolled up (and it can take days to hang them up so they can be used if they were bent, even around a form, when you bought them).

Synthetics may have changed the game a bit since the last time I looked; I imagine something more than the dropcloth grade cotton duck (which was the base fabric for all the lightest canvases I have ever worked with) could behave somehow better, but I haven't seen any evidence of them in my local Pro Photo Emporia.


I don't know what kids are doing with muslin these days, but back in my day it was the placement alternative to dappled canvas bottoms. Muslin is not only much lighter and slightly cheaper, but it also removes wrinkles better. Yes, that was the point. Bringing the canvas to a location meant carrying a long, unwieldy roll of cloth, carefully folding it and having a regular crease pattern (which looks like a bad background image from the web page), or having a very prominent web of irregular creases . The canvas is a heavy cloth; he just wrinkled a lot. Muslin, on the other hand, is very light and glorifies the ability to take on an almost fractal irregular wrinkled texture if you simply wrinkle it and store it in a bag. When that texture is combined with the smooth mottling that is usually applied, it just disappears. If you want a smooth background, you should treat the muslin with almost the same care as the canvas.

Muslin tends to be made from a higher grade yarn than canvas (looms and home yarns are used for things like bedding rather than industrial applications and motifs for painting when they are not doing their twenty minutes a year of photographic applications) That means fading and dying results tend to be better – you can get good white and bright, vivid colors without painting as well as dark dyes without gloss. But wrinkles and folds will always be a problem if you need to store or move them.

Jersey (Fabrics)

T-shirts tend to get around the problem of wrinkles and wrinkles very clearly, which is why they create great solid color backgrounds. Being fabrics, of course, they will wrinkle and wrinkle, but those wrinkles and folds can be easily stretched. But as the man said, there is no free lunch.

T-shirts don't just hang there; they practically need to be stretched. If you put a plain jersey bottom panel on a standard bottom bracket, the top may be the advertised width, but it will come down to this little six-inch-wide cylinder at the bottom. You must fasten the fabric to the studs to maintain width, and the clamps must be frequent enough to avoid creating a visible diamond pattern due to variations in tension. And it is more or less a background material; It doesn't work well without problems, even if you try to stretch and weigh the perimeter of the piece on the floor / table. (Elasticity means that a bubble almost always appears somewhere.) However, it is a fantastic popup and works great in a frame – wrinkles just disappear.

And therein lies the problem of pills. If you never need to clean the fabric, it can be like new for a long time. If you need to wash it, you must remember that this is actually just an oversized shirt. Handwashing in cold water in the tub by squeezing it (no shaking) and hanging it to dry works well, but anything harder than that will ruin it. If it's something that's going to experience a lot of shaking, it's the wrong tissue.

Velvet / velvet

These make great solid colors (assuming we are not talking about the "squashed" variety) and there is no substitute for black velvet as an absolute black, apart from the immense distance: light enters and does not come out again. The nap hides wrinkles and wrinkles on the base fabric very well. For lighter / brighter colors, you may need to brush the surface of the nap to avoid apparent color changes (one of those big slate erasers which is essentially a foam rubber block with a stick inside and a suede glued onto one side is very fast and effective for this). Velvet / Velvet is ideal for solid whites, solid absolute blacks, and chromakey-like colors, and a white or gray panel combined with gelled lighting can make very smooth gradients. Velvets can be surprisingly light (although some made as lining fabrics, i.e. fabrics of adequate weight to use for coats, and those based on a knitted fabric rather than a fabric, can be surprisingly heavy).

Velvet and velvet, however, are lint magnets, and the lighter colors can detect dirt handling quickly. They are not absolutely suitable for uninterrupted applications involving anything heavy (such as a person or even a large tabletop subject) – napping again after being completely crushed is a difficult job.

There is a wide variety of washability: the name really only tells you what the fabric surface looks like; It doesn't tell you much about the underlying construction. Some will go bald if you see them funny, some will feel, others will laugh at your "hot" water and small washing machines. Some will dry quickly and easily, others will soak up Lake Superior in one gulp and be ready to use again next February if you're lucky. It is probably safe to assume that any company that relies on the goodwill of professional photographers (Lastolite, Photek, Photoflex, Westcott, etc.) will sell you something suitable for that purpose; but as with anything else in life, I would be suspicious of anything that is priced at the "too good to be true" level; It may work immediately, but it is probably disposable.

Really white

If you are working in a small space (there is no real space to separately illuminate the background evenly from the front) and you need something that is digitally white instead of just white (i.e. something that not only looks white to the viewer, and it may have shadows, but in reality it will be all F when you look at the values), then it may be worth looking back. Commercially, that means using a huge softbox or something like Lastolite's Hilite background system (which is essentially a low-sidelight softbox). A DIY version would not be too difficult to create: the only piece that is critical is the diffusion panel, and that is really "critical" in the sense that it must be perfect (one piece). The rest is just reflective fabric (which may be the cheapest silver lamé you can find at the fabric store, and can be full of stitching everywhere) and a hanging frame (PVC, anyone?).

Analysis of the food traceability system developed by Walmart with Hyperledger Fabric – Cryptocurrency corner

Creating a (traceability) system for the entire food supply ecosystem is always a challenge. At Oodles, we believe that blockchain technology is a good option to address this problem with the Hyperledger application development services. Blockchain enables trust, immutability and transparency in the business ecosystem. In the past, many companies tried to create a traceability system, but they never escalated because they were centralized databases. Blockchain is a decentralized and shared ledger that can improve the legacy food system. Given the potential of blockchain in business, Walmart decided to develop two proof-of-concept (POC) projects.

Google Analytics: Is there any analogue for the Fabric board?

I existed a lot with the Fabric board, which clearly shows all the things I needed in one place. But this day is coming: Fabric will close very soon, and I don't know where to find such a simple analogue, which will be useful for non-professional sellers.

The Google Firebase Analytics panel seems very complicated to my opinion, and it works very slowly. Are there other analogs?

The string code is not implemented in the test network after running the implementation script in the Hyperledger Fabric 2.0 documentation

I ran the script ./ deployCC, then you cannot implement it on the network (Fabric 2.0), this is the error:

deploying chaincode on channel 'mychannel'

Vendoring Go dependencies ...
go: unknown subcommand "mod"
Run 'go help' for usage.
Finished vendoring Go dependencies
Using organization 1
++ peer lifecycle chaincode package fabcar.tar.gz --path 
../chaincode/fabcar/go/ --lang golang --label fabcar_1
++ res=1
++ set +x
Error: error getting chaincode bytes: listing deps for pacakge 
../chaincode/fabcar/go/ failed: exit status 2
!!!!!!!!!!!!!!! Chaincode packaging on peer0.org1 has failed 

ERROR !!! Deploying chaincode failed

terminal – Fabric | cancel error message

Good wednesday guys

I'm struggling with Fabric today and I can't find a way out :(.

I installed everything according to the documentation provided by + some other commands to access a user database in Opsgerrit.

The steps respectively:

  1. sudo easy_install pip; sudo pip install fabric;

  2. pip install pytz dateutils requests PyYAML docker-py

3)git clone ssh://

cd fabric

sudo pip install virtualenv

virtualenv env

source env/bin/activate

pip install -r requirements.txt

fab -l

and now the fight I'm talking about:

  1. fab utils.setup_ops_git

Every time I execute this command or try to execute another command with fab I get the following error:

Random number + abort