Search, replace, and store again

This tutorial lesson provides examples of content adaptations involving search and replace, and then storing the resource back to the DB. It requires the PHP Functions via Schema extension.

🔥 Tips:

The PHP Functions via Schema extension provides the following "search and replace" fields:

  • _strReplace: Replace a string with another string
  • _strReplaceMultiple: Replace a list of strings with another list of strings
  • _strRegexReplace: Search for the string to replace using a regular expression
  • _strRegexReplaceMultiple: Search for the strings to replace using a list of regular expressions

Search and replace a string permalink

This GraphQL query retrieves a post, replaces all occurrences of some string with another one in the post's content and title, and stores the post again:

query GetPostData(
$postId: ID!
$replaceFrom: String!,
$replaceTo: String!
) {
post(by: { id: $postId }) {
title
adaptedPostTitle: _strReplace(
search: $replaceFrom
replaceWith: $replaceTo
in: $__title
)
@export(as: "adaptedPostTitle")

rawContent
adaptedRawContent: _strReplace(
search: $replaceFrom
replaceWith: $replaceTo
in: $__rawContent
)
@export(as: "adaptedRawContent")
}
}

mutation UpdatePost($postId: ID!)
@depends(on: "GetPostData")
{
updatePost(input: {
id: $postId,
title: $adaptedPostTitle,
contentAs: { html: $adaptedRawContent },
}) {
status
errors {
__typename
...on ErrorPayload {
message
}
}
post {
id
title
rawContent
}
}
}

To execute the query, we provide the dictionary of variables with the strings to search and replace:

{
"postId": 1,
"replaceFrom": "Old string",
"replaceTo": "New string"
}

Search and replace multiple strings permalink

This is the same query as above, but by using _strReplaceMultiple we can replace a list of strings with another list of strings:

query GetPostData(
$postId: ID!
$replaceFrom: [String!]!,
$replaceTo: [String!]!
) {
post(by: { id: $postId }) {
title
adaptedPostTitle: _strReplaceMultiple(
search: $replaceFrom
replaceWith: $replaceTo
in: $__title
)
@export(as: "adaptedPostTitle")

rawContent
adaptedRawContent: _strReplaceMultiple(
search: $replaceFrom
replaceWith: $replaceTo
in: $__rawContent
)
@export(as: "adaptedRawContent")
}
}

mutation UpdatePost($postId: ID!)
@depends(on: "GetPostData")
{
updatePost(input: {
id: $postId,
title: $adaptedPostTitle,
contentAs: { html: $adaptedRawContent },
}) {
status
errors {
__typename
...on ErrorPayload {
message
}
}
post {
id
title
rawContent
}
}
}

The dictionary of variables now receives a list of strings to search and replace:

{
"postId": 1,
"replaceFrom": ["Old string 2", "Old string 2"],
"replaceTo": ["New string1", "New string 2"]
}

This GraphQL query does a regex search and replace to add missing links in the post's HTML content:

query GetPostData($postId: ID!) {
post(by: { id: $postId }) {
id
rawContent
adaptedRawContent: _strRegexReplace(
searchRegex: "#\\s+((https?)://(\\S*?\\.\\S*?))([\\s)\\[\\]{},;\"\\':<]|\\.\\s|$)#i"
replaceWith: "<a href=\"$1\" target=\"_blank\">$3</a>$4"
in: $__rawContent
)
@export(as: "adaptedRawContent")
}
}

mutation UpdatePost($postId: ID!)
@depends(on: "GetPostData")
{
updatePost(input: {
id: $postId,
contentAs: { html: $adaptedRawContent },
}) {
status
errors {
__typename
...on ErrorPayload {
message
}
}
post {
id
title
rawContent
}
}
}

All URLs which are not surrounded by an anchor tag, such as:

<p>Visit my website: https://mysite.com.</p>

...are added the correspondig <a> tag around them (while also removing the domain from the text, and adding a target to open in a new window), becoming:

<p>Visit my website: <a href="https://mysite.com" target="_blank">mysite.com</a>.</p>

🔥 Tips:

Replacing HTTP with HTTPS permalink

This GraphQL query replaces all http URLs with https in HTML image sources:

query GetPostData($postId: ID!) {
post(by: {id: $postId}) {
id
rawContent
adaptedRawContent: _strRegexReplace(
searchRegex: "/<img(\\s+)?([^>]*?\\s+?)?src=([\"'])http:\\/\\/(.*?)/"
replaceWith: "<img$1$2src=$3https://$4$3"
in: $__rawContent
)
@export(as: "adaptedRawContent")
}
}

mutation UpdatePost($postId: ID!)
@depends(on: "GetPostData")
{
updatePost(input: {
id: $postId,
contentAs: { html: $adaptedRawContent },
}) {
status
errors {
__typename
...on ErrorPayload {
message
}
}
post {
id
title
rawContent
}
}
}

Extensions referenced in this tutorial permalink

  1. Field To Input permalink

    Retrieve the value of a field, manipulate it, and input it into another field or directive, all within the same operation.

  2. Multiple Query Execution permalink

    Combine multiple queries into a single query, sharing state across them and executing them in the requested order.

  3. PHP Functions via Schema permalink

    Manipulate the field output using standard programming language functions available in PHP.