Solved: Column definition sintax using js file - Page 2

giopappy · 05-08-2024 06:08 AM

Hi All,

to make more flexible the creation of standard views, I'm trying to define them using javascript, but I can't assign a description to columns. This is an example code:

const col = "COL1: \"test col\"";
publish("testview",{
    type: "view",
    columns: {col}
}).query(ctx => "SELECT 1 AS COL1")

The view has been created but no description is available for COL1

This work:

publish("testview",{
    type: "view",
    columns: {COL1: "test col"}
}).query(ctx => "SELECT 1 AS COL1")

but I've to put this sentence in a for loop to create lots of views based on different queries.

Can anyone help me?

Thanks

ms4446

You're correct in avoiding the use of eval for dynamically constructing code due to its potential security and performance implications. Instead, a cleaner and safer approach is to create views with variable numbers of columns and distinct queries using JavaScript object manipulation. Here’s how you can achieve this:

Example:

 

const viewDefinitions = [
  {
    name: "view1",
    columns: [
      { name: "COL1", description: "Description for COL1" },
      { name: "COL2", description: "Description for COL2" }
    ],
    query: () => `SELECT 1 AS COL1, 2 AS COL2` // Custom query for view1
  },
  {
    name: "view2",
    columns: [
      { name: "COL3", description: "Description for COL3" },
      { name: "COL4", description: "Description for COL4" },
      { name: "COL5", description: "Description for COL5" }
    ],
    query: () => `SELECT 3 AS COL3, 4 AS COL4, 5 AS COL5` // Custom query for view2
  }
  // Additional view definitions can be added here as needed
];

viewDefinitions.forEach(viewDef => {
  const columnDefinitions = viewDef.columns.reduce((acc, col) => {
    acc[col.name] = col.description; // Dynamically build column definitions
    return acc;
  }, {});

  publish(viewDef.name, { type: "view", columns: columnDefinitions })
    .query(viewDef.query); // Apply the custom query for this view
});

Explanation:

viewDefinitions Array: This contains objects, each defining a view's configuration, including the name, columns, and the query.
Dynamic Columns Object: Uses .reduce() on the columns array to transform it into the required object structure for the columns property in the publish function.
publish Call: Invokes the publish function with the dynamically constructed columns object, the view's name, and specifying it as a "view".
query() Call: Chains this method to publish to assign the custom SQL query for the view.

Key Improvements:

Structured and Clear: Each view is neatly defined within its own object, making the code easy to manage and update.
Security Enhanced: Avoids the security risks associated with eval by utilizing safe JavaScript practices.
Flexible and Customizable: Allows for easy addition and modification of views by adjusting the viewDefinitions array.
Adaptable Queries: Each view can have a tailored query, enhancing the versatility for specific requirements.

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