Nov

How to access object attributes based on a variable in Typescript

Nov 08, 2019

Typescript is obscurely particular with accessing attribute keys on objects that lack a generic signature. Adding generic signatures reduces type-safety though.

Here’s a Typescript-friendly way to verify an attribute exists in an object, and then access that attribute.

// implicitly typed object
const myObj = {
  Hello: "world"
};

const myObjKey = "Hello";

// The commonly recommended way to check if an attribute exists,  
// which throws a no signature lint error Element implicitly 
// has any type (TS7053) in Typescript
//
// if (myObj[myObjKey]) {
//     ...
// }

// The 'in' way, which Typescript likes
if (myObjKey in myObj) {
  // Now that we've confirmed the attribute exists, it's
  // type-safe to recast myObjKey and access it as an attribute
  console.log(myObj[myObjKey as keyof typeof myObj]);
}

// implicitly typed object

const myObj = {

Hello: "world"

};

const myObjKey = "Hello";

// The commonly recommended way to check if an attribute exists,

// which throws a no signature lint error Element implicitly

// has any type (TS7053) in Typescript

// if (myObj[myObjKey]) {

// ...

// }

// The 'in' way, which Typescript likes

if (myObjKey in myObj) {

// Now that we've confirmed the attribute exists, it's

// type-safe to recast myObjKey and access it as an attribute

console.log(myObj[myObjKey as keyof typeof myObj]);

}

This post originally posted at https://blog.smartlogic.io/accessing-object-attributes-based-on-a-variable-in-typescript/

5 years ago Short URL Comments

Programming/Uncategorized/Web-Dev

Mar

Drupal 7: Converting a text field to a long text (aka textarea) field

Mar 20, 2015

Realize later on that text field you created needs to actually be a long text field? You’re not alone.

After doing some research, I found zero complete solutions. The ones I found leave problemattic remnants in the database, which can cause hard to diagnose issues such as restricted field length. See references.

Luckily for you, the drush script below will do a more complete conversion.

Thanks go out to the references though, for getting me started.

<?php

/**
 * Change a field from textfield to textarea
 * Unlike other guides online, this one actually corrects the blob values
 * Run this using drush: `drush scr <filepath>`
 */

$field_name = "field_test_text_field_2";

$rows = db_query("SELECT id,data FROM {field_config} WHERE field_name = '{$field_name}' ")->fetchAll(PDO::FETCH_OBJ);

foreach ($rows as $row ){
 $row->data=unserialize($row->data);
 unset($row->data['settings']['max_length']);
 $row->type="text_long";
 drupal_write_record("field_config", $row, "id");
}

// Update field_config_instance
$rows = db_query("SELECT id,data FROM {field_config_instance} WHERE field_name = '{$field_name}'")->fetchAll(PDO::FETCH_OBJ);

foreach ($rows as $row ){
 $row->data=unserialize($row->data);
 $row->data['widget']['type']='text_textarea';
 unset($row->data['widget']['settings']['size']);
 $row->data['widget']['settings']['rows']=3;
 drupal_write_record("field_config_instance", $row, "id");
}

// Update the field table
db_change_field("field_data_{$field_name}", "{$field_name}_value", "{$field_name}_value", array(
 "type" => "varchar",
 "length" => "20000",
));
db_change_field("field_revision_{$field_name}", "{$field_name}_value", "{$field_name}_value", array(
 "type" => "varchar",
 "length" => "20000",
));

// Clear caches.
field_cache_clear(TRUE);

<?php

/**

* Change a field from textfield to textarea

* Unlike other guides online, this one actually corrects the blob values

* Run this using drush: `drush scr <filepath>`

$field_name = "field_test_text_field_2";

$rows = db_query("SELECT id,data FROM {field_config} WHERE field_name = '{$field_name}' ")->fetchAll(PDO::FETCH_OBJ);

foreach ($rows as $row ){

$row->data=unserialize($row->data);

unset($row->data['settings']['max_length']);

$row->type="text_long";

drupal_write_record("field_config", $row, "id");

}

// Update field_config_instance

$rows = db_query("SELECT id,data FROM {field_config_instance} WHERE field_name = '{$field_name}'")->fetchAll(PDO::FETCH_OBJ);

foreach ($rows as $row ){

$row->data=unserialize($row->data);

$row->data['widget']['type']='text_textarea';

unset($row->data['widget']['settings']['size']);

$row->data['widget']['settings']['rows']=3;

drupal_write_record("field_config_instance", $row, "id");

}

// Update the field table

db_change_field("field_data_{$field_name}", "{$field_name}_value", "{$field_name}_value", array(

"type" => "varchar",

"length" => "20000",

));

db_change_field("field_revision_{$field_name}", "{$field_name}_value", "{$field_name}_value", array(

"type" => "varchar",

"length" => "20000",

));

// Clear caches.

field_cache_clear(TRUE);

References:

http://www.pixelite.co.nz/article/convert-existing-textfield-textarea-drupal-7/
http://www.up2technology.com/blog/converting-drupal-fields/

9 years ago Short URL 11 Comments

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How to access object attributes based on a variable in Typescript

Drupal 7: Converting a text field to a long text (aka textarea) field