mirror of
https://github.com/oceanprotocol/docs.git
synced 2024-11-26 19:49:26 +01:00
105 lines
3.4 KiB
Markdown
105 lines
3.4 KiB
Markdown
---
|
|
description: This page shows how you can get datatokens & download an asset
|
|
---
|
|
|
|
# Consume Flow
|
|
|
|
Consume flow highlights the methods for getting a datatoken for accessing an asset from Ocean Market and for downloading the content of the asset.
|
|
|
|
We assumed that you accomplished the publish flow presented previously.
|
|
|
|
Now let's see how can Bob get access to Alice's asset in order to download/consume it.
|
|
|
|
### Get access for a dataset 🔑
|
|
|
|
Below, we show four possible approaches:
|
|
|
|
* A & B are when Alice is in contact with Bob. She can mint directly to him, or mint to herself and transfer to him.
|
|
* C is when Alice wants to share access for free, to anyone
|
|
* D is when Alice wants to sell access
|
|
|
|
<figure><img src="../../.gitbook/assets/gif/giphy.webp" alt="" width="199"><figcaption></figcaption></figure>
|
|
|
|
In the same Python console:
|
|
|
|
```python
|
|
from ocean_lib.ocean.util import to_wei
|
|
|
|
#Approach A: Alice mints datatokens to Bob
|
|
datatoken.mint(bob, to_wei(1), {"from": alice})
|
|
|
|
#Approach B: Alice mints for herself, and transfers to Bob
|
|
datatoken.mint(alice, to_wei(1), {"from": alice})
|
|
datatoken.transfer(bob, to_wei(1), {"from": alice})
|
|
|
|
#Approach C: Alice posts for free, via a dispenser / faucet; Bob requests & gets
|
|
datatoken.create_dispenser({"from": alice})
|
|
datatoken.dispense(to_wei(1), {"from": bob})
|
|
|
|
#Approach D: Alice posts for sale; Bob buys
|
|
# D.1 Alice creates exchange
|
|
price = to_wei(100)
|
|
exchange = datatoken.create_exchange({"from": alice}, price, ocean.OCEAN_address)
|
|
|
|
# D.2 Alice makes 100 datatokens available on the exchange
|
|
datatoken.mint(alice, to_wei(100), {"from": alice})
|
|
datatoken.approve(exchange.address, to_wei(100), {"from": alice})
|
|
|
|
# D.3 Bob lets exchange pull the OCEAN needed
|
|
OCEAN_needed = exchange.BT_needed(to_wei(1), consume_market_fee=0)
|
|
ocean.OCEAN_token.approve(exchange.address, OCEAN_needed, {"from":bob})
|
|
|
|
# D.4 Bob buys datatoken
|
|
exchange.buy_DT(to_wei(1), consume_market_fee=0, tx_dict={"from": bob})
|
|
```
|
|
|
|
For more info, check [Technical Details](technical-details.md) about ocean.py most used functions and also the smart contracts for [Dispenser](https://github.com/oceanprotocol/contracts/blob/main/contracts/pools/dispenser/Dispenser.sol) & [Fixed Rate Exchange](https://github.com/oceanprotocol/contracts/blob/main/contracts/pools/fixedRate/FixedRateExchange.sol).
|
|
|
|
### Consume the asset ⬇️
|
|
|
|
To "consume" an asset typically means placing an "order", where you pass in 1.0 datatokens and get back a url. Then, you typically download the asset from the url.
|
|
|
|
Bob now has the datatoken for the dataset! Time to download the dataset and use it.
|
|
|
|
<figure><img src="https://media.giphy.com/media/px8O7NANzzaqk/giphy.gif" alt="" width="375"><figcaption></figcaption></figure>
|
|
|
|
In the same Python console:
|
|
|
|
```python
|
|
# Bob sends a datatoken to the service to get access
|
|
order_tx_id = ocean.assets.pay_for_access_service(ddo, {"from": bob})
|
|
|
|
# Bob downloads the file. If the connection breaks, Bob can try again
|
|
asset_dir = ocean.assets.download_asset(ddo, bob, './', order_tx_id)
|
|
|
|
import os
|
|
file_name = os.path.join(asset_dir, "file0")
|
|
```
|
|
|
|
Let's check that the file is downloaded. In a new console:
|
|
|
|
```bash
|
|
cd my_project/datafile.did:op:*
|
|
cat file0
|
|
```
|
|
|
|
The _beginning_ of the file should contain the following contents:
|
|
|
|
```bash
|
|
% 1. Title: Branin Function
|
|
% 3. Number of instances: 225
|
|
% 6. Number of attributes: 2
|
|
|
|
@relation branin
|
|
|
|
@attribute 'x0' numeric
|
|
@attribute 'x1' numeric
|
|
@attribute 'y' numeric
|
|
|
|
@data
|
|
-5.0000,0.0000,308.1291
|
|
-3.9286,0.0000,206.1783
|
|
...
|
|
```
|
|
|