Display a link from an existing link relation

[czcpf]

Hello,

Let's say we have EntityA, EntityB and another EntityC. How do I create a notStorable field link to EntityC in EntityA so that it can be displayed and sorted in list view. (Assume I define a loader to set its id and name).

Custom/Resources/metadata/entityDefs/EntityA.json

{
    "fields": {​
        "entityB": {
        "type": "link",
        "isCustom":true,
    },​
    "links": {
        "entityB": {
            "type": "belongsTo",
            "foreign": "entityAs",
            "entity": "EntityB",
            "isCustom": true
        },​
    }
},

Custom/Resources/metadata/entifyDefs/EntityB.json

{
    "fields": {​
        "entityAs": {
            "type": "linkMultiple",
           "isCustom":true,
        },​
        "entityC": {
            "type": "link",
            "isCustom": true,
        },​
    },
    "links": {
        "entityAs": {
            "type": "hasMany",
             "foreign": "entityB",
             "entity": "EntityA",
             "isCustom": true
        },​
        "entityC": {
            "type": "belongsTo",
             "foreign": "entityBs",
             "entity": "EntityC",
            "isCustom": true
        },​
    }
}

[rabii]

hey czcpf

If you have the relationship set already between entityC and entityA then you can take advantage of foreign fields which are not sortable by default, e.g you can do something like below:

{
    "fields":{
        "entityB": {
                "readOnly": true,
                "type": "foreign",
                "link": "entityB",
                "field": "name",
                "view": "views/fields/foreign-varchar", // you an even create your own custom view
                "notStorable": true
            }
    },

    "links": {
        "entityB": {
            "type": "belongsTo",
            "entity": "EntityB",
            "foreign": "entityAs"
        },
    }
}​ 

[czcpf]

Thats the issue though. There is no existing relationship between entityA and entityC. The relationship goes like entityA->entityB-entityC. So entityA has a single link to entityB && entityB has a single link to entityC. I want to create a readOnly, notStorable field for entityC in entityA. Espo doesn't seem to allow you to create a foreign field to a link in the foreign entity.

[rabii]

I don't think it would be possible, because this set up should represent a relationship between the entities otherwise there could be no link. i suggest that you create a relationship (readonly) between entityA and entityC, unless if you want to customise how relationships work in espo and add your own something like hasOneThrough or hasManayThrough.

Personnaly i would just add that relationship and set it up as a readOnly link and maybe use formula or hooks to wire it all up.

[czcpf]

Thanks. How do you create a readonly relationship?

[rabii]

Hey

You can try something as below, create a relationship between entityA and entityC as below, then use formula on entityB so that when the field relationship of entityC is changed then update it on entityA, i think the structure below would allow to use a notsortable link between the two entities:

​(entityA) One-to-One Left (entityC)

{
    "fields": {
        "entityCField": {
            "type": "linkOne",
            "readOnly": true,
            "notStorable": true,
            "view": "views/fields/link-one"
        }
    },

    "links": {
        "entityCField": {
            "type": "hasOne",
            "entity": "entityC",
            "foreign": "entityAField"
        },
    }
}


(entityC) One-to-One Right (entityA)

{
    "fields": {
        "entityAField": {
            "type": "link",
            "layoutDetailDisabled": true
        }
    },

    "links": {
        "entityAField": {
            "type": "belongsTo",
            "entity": "entityA",
            "foreign": "entityCField"
        },
    }
}​ 

This should work and it would set the link as a notSortable.

I hope this helps, sorry couldn't come with proper name fields but just used entity like field name.