CrowdFunding | 基于区块链（以太坊）技术的安全众筹系统 | Cryptocurrency library

Do i need something in Javascript?

No, you don't. At least not for a

with regular height
• elements.
  Regular Height
• elements

For a

with regular height
• elements, it will suffice to use:
  • an explicit height for
  • an explicit max-height for
    • overflow-y: auto on

      Working Example:

You might decide to switch to a newer version of Solidity (current is 0.8.4), where now is deprecated so I already used block.timestamp instead. It's the same thing - now was just its alias.

The SafeMath library checks whether an arithmetic operation (such as multiplication or addition) on two unsigned integers would overflow/underflow. If it would, it throws an exception. If it wouldn't, it performs the arithmetic operation. Since Solidity 0.8 this is done automatically and SafeMath is not needed, so another reason to use the current version.

In Solidity 0.8 and newer, if this would overflow, it would throw an exception automatically

I think you've missed a few entities and relationships.

I found the following to be working. From what I can gather, one problem was, that the required encoding was form, not json. Another problem was, that from the request you posted, you did not send any body, meaning information on what you want to get back from the API. As it is a pain to type all that out, I typically copy the curl command from chrome and paste it here to get the body formatted nicely.

If you plan on doing this frequently, I recommend putting your email adress or something in the headers of your request, so that Sysadmins have a chance of contacting you if this behavior is not wanted.

I believe the answer to futures is no. Here's more explanation:

I think it is better to think about what programming primitives are available inside a Substrate runtime, instead of trying to use a concept from general purpose programming (future) and try and re-purpose it for the Substrate runtime (top-down vs. bottom-up viewpoint).

So, let's think about the lifecycle of a runtime and see what makes sense there:

Inside a runtime, you are kinda stuck in a box. A (wasm) runtime code is spawned and executed by the (always native) client whenever a new block is there to be imported (or authored, but let's assume just importing for now), and killed and set aside afterwards (at least from the perspective of the runtime -- the client has runtime caching). My point being, anything that you don't commit to state (i.e. write in storage) at the end of the execution of each block is lost. This includes all the local variables, stack, heap, and anything else. So even if you were to use a future to spawn a task, that doesn't really fit into the programming model of Substrate runtimes, because even if that future lived in the runtime, as soon as the block is done, the wasm instance is dead and so is the future.

That is all ignoring the fact that you can only use crates that support no_std in the runtime, so not every async library will be available anyhow.

The main solution, as I hinted, is probably something that uses state storage to record the starting point of the auction, so that x blocks later you can still know when you started it, and if some threshold is passed, then you can finish your auction. You could use either a timestamp or a number of blocks for your duration of auction. Something along the lines of:

As Eldar said in the comment:

Some of the text you're writing to CSV might contain newlines. You can remove them like so:

Try to render the graph after receiving the response from the http request, maybe with an if statement and a variable as flag:

As Dimitri mentioned (and also confirmed here) you should not use ->all() when you only need the count and not the data in the model itself.

Replace $data like so: